An annotated checklist of the nematodes parasites of Argentinian freshwater fishes is presented. This review includes information for 42 taxa of parasitic nematodes from 56 species of freshwater fish hosts. Fourty nematode species have been reported as adults and two as larvae. Camallanidae was the nematode family with the highest number of taxa (12 species), followed by Cucullanidae (4 species) and Raphidascarididae (4 species and 1 at genus level). The larval nematode Contracaecum sp. was the parasite with the widest range of host species, follow by Spirocamallanus hilarii, Spirocamallanus inopinatus, and Camallanus corderoi. Of the 570 species of freshwater fishes reported in Argentina, only 65 (11.4 %) were recorded as hosts of nematodes. Most records were in Characiformes, Siluriformes and Galaxiiformes, which may reflects sampling effort, since its abundance and widely distributions across differents ichthyogeographic provinces of Argentina. Most sampling were done in Great River and Patagonian ichthyogeographic provinces. The small number of examined fish hosts and geographically biased studies may not reflect the real richness and distribution of these parasites. Other obstacles that also contributes to the lack of completeness of this checklist are the problems in the taxonomic validity of some nematode species, doubtful host identification, and poor taxonomic resolution for larval stages of nematodes. Therefore, it is strongly recommended to deposit voucher specimens, including also of the hosts in reference collection, as well as performing integrative studies to elucidate the real taxonomic identity of nematode larvae. This is the first compilation on the nematode parasites of freshwater fishes from Argentina, including three nematode taxa recorded for new host records and four from new localities. Despite this study is exhaustive, the knowledge about parasitic nematodes from Argentinian freshwater fishes is far from complete, since some hydrological basin mainly in Pampean and Andean Cuyan regions and some host families remain unexplored in terms of nematode parasite detection.
INTRODUCTION
The class Nematoda represents a taxonomical, ecological and geographically diverse helminth assemblage (Luque et al., 2011). To date, nematode biodiversity (parasitic and free living forms) has been estimated at 25 043 species, thus representing the fourth species-rich taxa within the kingdom Animalia (Zhang, 2013). Nematodes represent a conspicuous component of the parasite assemblages in fishes and have a considerable importance from veterinary medicine and public health points of view (Moravec, 1998; Luque et al., 2011). According to Luque et al. (2016), nematodes are the fourth taxon in terms of species reported in fishes from Southamerica, after Monogenea, Trematoda, and Cestoda.
Research on freshwater fish nematodes from Argentina date back to mid 20th Century. The first publication was by Shuurmans-Stekhoven (1951), who reported larvae of Contracaecum sp. in Pseudoplatystoma corruscans (Spix & Agassiz) (= Platystoma sp.) in the Paraná River, Corrientes Province. Subsequently, Zeiss & Seigneur (1981) reported Contracaecum rudolphii Hartwich, 1964 in Pimelodus albicans (Valenciennes) and Salminus brasiliensis (Cuvier) from Los Quirogas Dam, Santiago del Estero Province. Later Hamann (1982a, b, c, 1984, 1985, 1986, 1995/1996) performed several taxonomic studies about nematode parasites of freshwater fishes from Paraná River basin, contributing to knowledge about the parasitic nematodes of Argentinian freshwater fishes. From 1995 to today, the number of descriptions and/or reports have considerably increased (e.g., Ramallo & Torres 1995; Ramallo, 1997, 1999, 2008, 2011, 2012; Brugni & Viozzi, 1999, 2003, 2010; Ailán-Choke et al., 2014, 2017, 2018). Chemes & Takemoto (2011) published a commented list of helminth parasites of freshwater fishes from Middle Paraná System, and Rauque et al. (2018) included records of nematode parasites in a study about helminth parasites of alien freshwater fishes in Patagonia. However, an actualized checklist about nematode parasites of Argentinian freshwater fish has not yet been published. Therefore, the knowledge about the nematode parasites of Argentinian freshwater fishes is scattered and the studies are focused mainly on taxonomy.
The aim of this study is to update the list of nematode parasites of freshwater fishes from Argentina. It is based on the compilation of published papers and reports of species herein cited for the first time.
MATERIAL AND METHODS
We compiled and reviewed all publications refering to nematode parasites of Argentinean freshwater fishes (estuarineexcluded),during1951-2021.Thebibliographic search was complemented by the information gathered from Host-Parasite Database of the Natural History Museum, London (Gibson et al., 2005), Google Scholar, ScienceDirect and Web of Knowledge. We used the following keywords: Biodiversity, nematodes, parasites, freshwater fishes, Argentina, Parana River basin, Juramento River basin, Bermejo River basin, Colorado River, and Patagonia. Each taxonomic category of Nematoda is presented in alphabetical order, each one followed by author and publication year, and synonyms under which the original records appeared. The list also includes host(s) and localities in which the nematode species was collected (Lo), the geographical coordinates indicated in the publications, the site of infection (SI); the institution where the material is deposited and the accession numbers (MD); developmental stage (DS), references and remarks (when justified).
The taxonomy of nematodes follows Moravec (1998), Anderson et al. (2009), and Ailán-Choke & Pereira (2021) for camallanids. Collection acronyms, whenever possible, are as follows: In Argentina: CH-N-FML: Colección de Invertebrados (Sección Helmintos y Anélidos), Fundación Miguel Lillo, San Miguel de Tucumán; CECOAL: Centro de Ecología Aplicada, Corrientes, UNSa-IEBI-I: Colección de Invertebrados del Instituto para el Estudio de la Biodiversidad de Invertebrados, Universidad Nacional de Salta, Salta; CHMLP: Colección de Helmintología del Museo de La Plata, La Plata; MACN-Pa: Colección Nacional de Parasitología, Museo Argentino de Ciencias Naturales Bernardino Rivadavia; UNCo-Pa: Colección Parasitológica de la Universidad Nacional del Comahue, Bariloche; Colección del Museo Provincial de Ciencias Naturales Florentino Ameghino, Santa Fé, Argentina. In other countries: USNPC: U.S. National Parasite Collection, Beltsville, Maryland; IPCAS Helm.: Helminthology Collection, Institute of Parasitology, Academy of Sciences of the Czech Republic, České Budějovice; NHM: The Natural History Museum, London; CHIOC: Helminthological Collection of the Instituto Oswaldo Cruz, Rio de Janeiro, Brazil; IPUAT: Instituto de Parasitología de la Universidad Austral de Chile.
The fish taxonomy follows Mirande & Koerber (2015), Lucena & Gouvea Soares (2016), Mirande & Koerber (2020), Terán et al. (2020), Fricke et al. (2021), and Froese & Pauly (2021). The names of ichthyogeographic provinces follow López et al. (2008). Type material is indicated with H (Holotype), A (Allotype), and P (Paratype) after the collection acronym. The following abbreviations and symbols are used: *new host record by the present authors, **new locality record by the present authors, • indicates doubtful fish host; ◦ indicates doubtful record of parasite.
RESULTS
The parasite-host list comprises records of 42 taxa of nematode parasites (36 nominal species and 6 identified at generic level), belonging to 3 orders and 12 families. These parasites were associated with 56 species of freshwater fishes from 9 orders and 21 families (Table 1). Fourty nematode taxa were reported as adults and two unidentified species as larvae (Contracaecum sp. and Eustrongylides sp.). In the particular case of Hysterothylacium sp., it was recorded as larvae only in Odontesthes bonariensis (Valenciennes), while in the other fish hosts [Odontesthes hatcheri (Eigenmann) and Percichthys trucha (Valenciennes)] was recorded as adult. Camallanidae was the family with the highest number of species recorded (12), followed by Cucullanidae (4) and Raphidascarididae (4), whereas Guyanemidae and Philometridae are only represented by one species each. The larval nematode Contracaecum sp. was the parasite with the widest range of host species, parasitizing 28 fish species, follow by Spirocamallanus hilarii Vaz & Pereira, 1934 reported in 15 fish species, S. inopinatus Travassos, Artigas & Pereira, 1928 and Camallanus corderoi Torres, Teuber & Miranda, 1990; both in 10 fish species (see Table 1). Additionally, we reported new hosts for three taxa [Spirocamallanus hilarii, Rhabdochona acuminata (Molin, 1860) and Contracaecum sp.] and four nematodes were recorded in new localities [Cucullanus (Cucullanus) pinnai pinnai Travassos, Artigas & Pereira, 1928, Spirocamallanus hilarii, Rhabdochona acuminata and Contracaecum sp. in the present survey (see the Parasite-Host list)].
Fish orders with the highest number of nematode taxa were Siluriformes (32), Characiformes (24), and Galaxiiformes (11). Among Siluriformes, pimelodids present the highest number of nematode taxa recorded, Pimelodus albicans (Valenciennes) with eight taxa recorded, followed by P. maculatus Lacépède, and Pseudoplatystoma corruscans (Spix & Agassiz) (four each) (see Table 1). Trichomycterus spegazzini (Berg) (Siluriformes) has six nematode taxa recorded. Among Galaxiiformes, Galaxias maculatus (Jenyns) with nine taxa and G. platei Steindachner with eight taxa (see Table 1). In the case of Characiformes, the bryconid Salminus brasiliensis presents four taxa, the characids Astyanax lacustris (Luetken) and Oligosarcus jenynsii (Günther) has three taxa each one.
Table 1.
List of the Argentinian fish hosts and their nematodes (host species are presented by order and families in alphabetical order). * Doubtful identification of host species. ◦ Doubtful identification of nematode.
Continued
Continued
Most records of nematode parasite in freshwater fishes were from Great River ichthyogeographic province, especially in Salta and Corrientes provinces with 35 and 23 records of host-nematode parasite associations, respectively; and Patagonian ichthyogeographic provinces, represented mainly by studies carried out in Río Negro province with 36 records of host-nematode parasite associations. The remaining ichthyological provinces present few records or none like in the Andean-Cuyan region.
PARASITE-HOST LIST
Class Nematoda
Subclass Adenophorea
Order Enoplida
Superfamily Dioctophymatoidea
Family Dioctophymatidae
Genus Eustrongylides Jagerskiöld, 1909
Eustrongylides sp.
Host Galaxias maculatus (Jenyns)
SI: Caudal peduncle. Lo: Gutierrez Lake (41°12′S, 71°26′W) (Brugni & Viozzi, 1999) and (41°10′S, 71°24′W) (Guagliardo et al., 2019), Moreno Lake (41°04′S, 71°33′W) and Quillén Lake (39°25′S, 71°20′W) (Brugni & Viozzi, 2003), all Río Negro Province. MD: Not indicated. DS: Third and four-stage larvae were found inside melanized capsules. Remark: The larvae have always been found in conspicuous, external, and strongly melanized cysts on the caudal peduncle of G. maculatus (Brugni & Viozzi, 1999, 2003). Moravec (1998) mentioned that the species identification of Eustrongylides larvae is problematic and that the only reliable way to determine the species is to obtain adult nematodes from experimental infections to the definitive host (piscivorous bird).
Eustrongylides tubifex (Nitzsch, 1819)
Host Galaxias maculatus (Jenyns)
SI: Caudal peduncle. Lo: Moreno Lake and Quillén Lake, Río Negro Province. MD: Not reported. DS: Third stage larvae inside melanized capsules. Reference: Brugni & Viozzi (2003). SI: Caudal peduncle. Lo: Carilafquén, Neuquén Province. MD: MACN-Pa # 467 DS: Larvae. Reference: Viozzi et al. (2009).
Subclass Secernentea
Order Ascaridida
Superfamily Ascaridoidea
Family Anisakidae
Genus Contracaecum Railliet & Henry, 1912
Synonyms: Kathleena Leiper & Atkinson, 1914; Amphicaecum Walton, 1927; Cerascaris Cobb, 1929; Contracaecum (Ornitocaecum) Mozgovoi, 1951; Contracaecum (Synthetonema) Kreis, 1952.
Contracaecum sp.
Host Astyanax lacustris (Luetken)
SI: Corporal cavity. Lo: El Tunal Reservoir (25°15′S, 64°25′W), Salta Province. MD: Not indicated. DS: Larvae. Reference: Cancino & Ramallo (2008). SI: Corporal cavity. Lo: Itaú River (22°20′S, 64°05′W), Salta Province. MD: CH-N-FML# 7481. DS: Larvae. Reference: Antelo et al. (2016).
Host Cyprinus carpio Linnaeus
SI: corporal cavity. Lo: Casa de Piedra Reservoir (38°10′S, 67°09′W) and downstream Ballester Dam (38°43.9′S, 68°10′W), Colorado River; Herradura Backwater (38°57.44′S, 68°10.5′W); China Muerta Town (38°59.5′S, 68°19′W) and downstream Arroyito Dam (39°04.5′S, 68°33′W), Limay River; Allen City (39°02′S, 67°50′W) and Guardia Mitre Town (40°26.5′S, 63°41′W), Negro River; all Río Negro Province. MD: not indicated. DS: Larvae. Reference: Rauque et al. (2018). SI: Liver and visceral fat. Lo: Ingeniero Ballester dam (38°43′S, 68°10′W), Río Negro Province. MD: MACN-Pa # 562/1. DS: Larvae. Reference: Waicheim et al. (2014).
Host Galaxias maculatus (Jenyns)
SI: Corporal cavity, gonads. Lo: Moreno (41°05′S, 71°35′W) and Escondido (39°09′S, 71°17′W) Lakes, Río Negro Province. MD: Not indicated. DS: Larvae. Reference:Ortubayetal.(1994).SI:Abdominalcavity.Lo: Lakes Ñorquinco (39°09′S, 71°17′W); Quillén (39°25'S, 71°20'W); Huechulafquén (39°45′S; 71°25′W); Lácar (40°10′S; 71°30′W); Machónico (40°20′S, 71°33′W); Meliquina (40°23′S, 71°17′W); Filo Hua Hum (40°30′S, 71°17′W); Villarino (40°28′S, 71°35′W), Espejo Chico (40°35′S, 71°44′W); Traful (40°37′S, 71°25′W); Bailey Willis (40°38′S, 71°40′W); Espejo (40°41′S, 71°40′W) Correntoso (40°44′S, 71°39′W); Patagua (40°47′S, 71°37′W); Verde (40°46′S, 71°39′W); Nahuel Huapi (40°48′S, 71°39′W); El Trébol (41°04′S, 71°30′W); Morenito (41°05′S, 71°31′W); Escondido (41°05′S, 71°35′W); Mallín Ingeniero (41°15′S, 71°40′W); Llum (41°16′S, 71°40′W); Mascardi (41°17′S, 71°38′W); Fonck (41°18′S, 71°43′W); Hess (41°22′S, 71°43′W), Los Césares (41°19′S, 71°43′W); Verde (Villa Mascardi) (41°20′S, 71°31′W); Roca (41°21′S, 71°25′W); Los Moscos (41°21′S, 71°36′W); Juventus (41°22′S, 71°31′W); Huala Hue (41°25′S, 71°30′W); Steffen (41°31′S, 71°33′W); Rivers: Caleufu (40°30′S, 71°17′W), Ñirihuau (41°06′S, 71°10′W), Santa Cruz (50°00′S, 69°00′W), and Senillosa Channel (Limay River) (38°50′S, 68°30′W), Lakes. Patagonia. MD: MACN-Pa 464. DS: Larvae. References: Viozzi et al. (2009); Fernandez et al. (2015).
Host Galaxias platei
SI: Liver. Lo: Rosario Lake (43°15′S, 71°30′W), Chubut Province and Pueyrredón Lake (47°16′S, 72°00′W), Santa Cruz Province. MD: Not indicated. DS: Larvae. Reference: Ortubay et al. (1994).
Host Hoplias argentinensis Rosso et al.
SI: Free or encapsulated in abdominal cavity. Lo: Lago 2 (34°02′S, 59°07′W), Buenos Aires Province; Lagoon 2 (34°46′S, 63°38′W) and Lagoon 8 (33°06′S, 63°03′W) Córdoba Province. MD: Not indicated. DS: Third-stage larvae (Type 2). Reference: Mancini et al. (2014).
Host Hoplias misionera Rosso et al.
SI: Free or encapsulated in abdominal cavity, mesenteries. Lo: Pilcomayo River (22°22′S, 62°32′W), Salta Province. MD: CH-N-FML# 7771. DS: Larvae. Reference: Ramallo et al. (2020).
Host Jenynsia alternimaculata (Fowler) **
SI: Abdominal cavity, mesenteries. Lo: Isasmendi Stream (24°48′S, 65°26′W) and Stream afluent to Yacones River (24°31′S, 65°24′W), Salta Province. MD: CH-N-FML # 7514. DS: Larvae. Reference: Ailán-Choke et al. (2014). SI: abdominal cavity, mesenteries. Lo: Yacones River (24°40′S, 65°24′W) and Arias-Arenales River (24°48′S, 65°25′W), Salta Province. MD: UNSa-IEBI-I # 055. DS: Larvae. Reference: Present study. Remarks: New locality records.
Host Jenynsia obscura (Weyenbergh)
SI: Abdominal cavity. Lo: Vis-Vis River (27°15′S, 66°35′W) and Agua Fresca Dam (27°16′S, 66°35′W), Catamarca Province. MD: CH-N-FML # 07479. DS: Larvae. Reference: Ramallo & Padilla Bortayro (2011).
Host Odontesthes bonariensis (Valenciennes)
SI: Corporal cavity. Lo: lagoon south of the Córdoba Province (34°36′S, 64°24′W). MD: Not indicated. DS: Larvae. Reference: Mancini et al. (2005). SI: Corporal cavity. Lo: Shallow lake, Córdoba Province. MD: Not indicated. DS: Larvae. Reference: Mancini et al. (2006). SI: Corporal cavity. Lo: La Viña Reservoir, (31°17′S, 65°01′W), Córdoba Province. MD: Not indicated. DS: Larvae. Reference: Mancini et al. (2008). SI: Mesentery. Lo: Salada Grande, General Lavalle (36°55′S, 56°58′W) and Lacombe, Lezama (35°49′S, 57°49′W) lagoons, Buenos Aires Province. MD: CHMLP. DS: Larvae (L3). Reference: Drago (2012). SI: Free or encapsulated in abdominal cavity. Lo: Reservoir 3 (31°17′S, 65°01′W), Lake 1 (33°00′S, 63°55′W), Lagoon 3 (33°48′S, 64°51′W), Lagoon 5 (33°30′S, 63°06′W), Lagoon 6 (34°28′S, 64°23′W), Lagoon 7 (33°25′S, 62°53′W), Córdoba Province. MD: Not indicated. DS: Third-stage larvae (Type 2). Reference: Mancini et al. (2014). SI: Free or encapsulated in abdominal cavity. Lo: Reservoir 6 (32°48′S, 65°28′W), Lagoon 1 (33°59′S, 65°24′W), San Luis Province. MD: Not indicated. DS: Third-stage larvae (Type 2). Reference: Mancini et al. (2014). SI: Abdominal cavity. Lo: La Plata River (34°28′S, 58°23′W); Lacombe Pampaen Lake (35°49′S, 57°53′W); Chascomús pampean Lake (35°37′S, 58°00′W) Buenos Aires Province. MD: CHMLP. DS: Third-stage larvae. Reference: Flores et al. (2016). SI: Abdominal cavity. Lo: Casa de Piedra Reservoir (38°10′S, 67°09′W), Colorado River, La Pampa-Río Negro Provinces and Pellegrini Lake (38°41′S, 68°00′W), Neuquén River, Río Negro Province. MD: MACN-Pa. DS: Larvae. Reference: Rauque et al. (2018).
Host Odontesthes hatcheri (Eigenmann) (syn. Patagonina hatcheri)
SI: Intestine. Lo: Moreno Lake (41°06′S, 71°32′W), Río Negro Province; Alicurá Reservoir (40°40′S, 71°00′W), Río Negro-Neuquén Provinces. MD: Not indicated DS: Adults and larvae. Reference: Ortubay et al. (1994). SI: Intestine wall. Lo: El Chañar (Neuquén River) (38°34′S, 68°24′W), Caleufú River (Limay River) (40°23′S, 70°44′W), Neuquén Province; Carrilafquén Chica Lagoon (41°12′S, 69°25′W); Morenito lake (41°02′S, 68°34′W); Moreno Oeste Lake (41°06′S, 71°32′W), Río Negro Province; Musters (45°25′S, 69°11′W), Chubut Province. MD: CHMLP. DS: Third- stage larvae. Reference: Flores et al. (2016).
Host Oligosarcus jenynsii (Günther)
SI: Free or encapsulated in abdominal cavity. Lo: Lagoon 2 (34°46′S, 63°38′W), Lagoon 4 (33°09′S, 63°31′W), Lagoon 9 (34°53′S, 63°31′W), Córdoba Province. MD: Not indicated. DS: Third- stage larvae (Type 2). Reference: Mancini et al. (2014). SI: Free or encapsulated in abdominal cavity. Lo: Stream (33°45′S, 69°02′W) Mendoza Province. MD: Not indicated. DS: Third- stage larvae (Type 2). Reference: Mancini et al. (2014).
Host Olivaitchthys viedmensis (MacDonagh)
SI: Mesentery, stomach, intestine. Lo: Alicurá Reservoir (40°40′S, 71°00′W), Río Negro-Neuquén Provinces. MD: Not indicated. DS: Larvae. Reference: Ortubay et al. (1994).
Host Oncorhynchus mykiss (Walbaum)
SI: Corporal cavity. Lo: El Chañar Reservoir (38°34′S, 68°24′W) Neuquén River; Arroyito Reservoir (38°40′S, 68°33′W), Limay River; Ballester Dam (38°43′S, 68°10′W), Neuquén River; Ramos Mexia Reservoir (39°26′S, 68°56′W), Limay River; Piedra del Aguila Reservoir (40°19′S, 70°93′W), Limay River; Nahuel Huapi Lake (41°04′S, 71°25′W), Limay River; Moreno Lake (41°04′S, 71°33′W), Limay River, Escondido Lake (41°05′S, 71°35′W), Limay River, Río Negro Province; Traful Lake (40°38′S, 71°24′W), Limay River; Alicurá Reservoir (40°40′S, 71°00′W), Limay River, Neuquén Province; Cholila Lake (42°27′S, 71°40′W), Futaleufú River, Chubut Province. MD: MACN–Pa. DS: Larvae. Reference: Rauque et al. (2018).
Host Percichthys trucha (Valenciennes)
SI: Intestine. Lo: Alicurá Reservoir (40°40′S, 71°00′W), Río Negro-Neuquén Provinces; Moreno Lake (Río Limay) (41°04′S, 71°33′W), and Escondido Lake (41°05′S, 71°35′W), Río Negro Province. MD: Not indicated. DS: Larvae. Reference: Ortubay et al. (1994).
Host Piabina thomasi (Fowler) (syn. Bryconamericus thomasi) **
SI: Abdominal cavity, mesenteries. Lo: Puerta de Díaz Dam (25°16′S, 65°31′W), Salta Province. MD: UNSaIEBI-I # 145/1. DS: Larvae. Reference: Párraga & Davies (2015). SI: Abdominal cavity, mesenteries. Lo: Puerta de Díaz Dam (25°16′S, 65°31′W), Salta Province. MD: UNSa-IEBI-I # 0055. DS: Larvae. Reference: Present study. Remarks: New locality record.
Host Pimelodus albicans (Valenciennes)
SI: Free or encapsulated in abdominal cavity. Lo: Laguna 2 (35°46′S, 63°38′W), Laguna 7 (33°25′S, 62°53′W), Río Cuarto (33°09′S, 64°16′W), Córdoba Province. MD: Not indicated. DS: Third stage larvae (Type 2). Reference: Mancini et al. (2014). SI: Free or encapsulated in abdominal cavity, mesenteries, intestine or liver Lo: Misión La Paz, Pilcomayo River (22°22′S, 62°32′W), Rivadavia Department, Salta Province. MD: CH-N-FML#7772. DS: Third stage larvae (Type 2). Reference: Ramallo et al. (2020).
Host Psalidodon eigenmanniorum (Cope) (syn. Astyanax eigenmanniorum)
SI: Free or encapsulated in abdominal cavity. Lo: Castaño River, San Juan Province. MD: CH-N-FML #07799. DS: Larvae. Reference: Ramallo & Cancino (2021).
Host Psalidodon endy (Mirande, Aguilera & Azpelicueta) (syn. Astyanax endy) ***
SI: Abdominal cavity, mesenteries. Lo: Campo Alegre Dam (24°34′S, 65°21′W), Salta Province. MD: UNSaIEBI-I # 0055. DS: Larvae. Reference: Present study. Remarks: New host and locality records.
Host Pseudoplatystoma corruscans (Spix & Agassiz)
SI: Stomach and intestine. Lo: Parana River, Santa Fé Province. MD: CH-N-FML# 212 (missing material). DS: Larvae. Reference: Schuurmans Stekhoven (1951). SI: Free or encapsulated in abdominal cavity, mesenteries. Lo: Pilcomayo River (22°22′S, 62°32′W), Salta Province. MD: CH-N-FML #7769. DS: Larvae. Reference: Ramallo et al. (2020).
Host Pygocentrus nattereri Kner
SI: Free or encapsulated in abdominal cavity, mesenteries. Lo: Pilcomayo River (22°22′S, 62°32′W) Salta Province. MD: CH-N-FML# 7785. DS: Larvae. Reference: Ramallo et al. (2020).
Host Rhamdia quelen (Quoy & Gaimard)**
SI: Free or encapsulated in abdominal cavity. Lo: Lake 2, Buenos Aires (34°03′S, 59°07′W), Buenos Aires Province. MD: Not indicated. DS: Third-stage larvae (Type 2). Reference: Mancini et al. (2014). SI: Free or encapsulated in abdominal cavity. Laguna 2 (36°46′S, 63°38′W), Lagoon 9 (34°53′S, 63°31′W), Córdoba Province. MD: Not indicated. DS: Third-stage larvae (Type 2). Reference: Mancini et al. (2014). SI: Free or encapsulated in abdominal cavity. Lo: El Cero Dam, Figueroa Water System (27°07′S, 63°37′W), Santiago del Estero Province. MD: CH-N-FML # 07787. DS: Third stage larvae (Type 2). Reference: Present study. Remarks: New locality record.
Host Salminus brasiliensis (Cuvier)
SI: Intestinal caecum and peritoneum of intestine. Lo: Río Hondo Reservoir (27°31′S, 64°53′W) Tucumán-Santiago del Estero Provinces. MD: CH-FML # 01830 and IPUAT # 0247. DS: Larvae. Reference: Ramallo & Torres (1995).
Host Salmo salar Linnaeus
SI: Mesentery, stomach and intestine. Lo: Alicurá Reservoir (40°40′S, 71°00′W), Río Negro-Neuquén Provinces. MD: Not indicated. DS: Larvae. Reference: Ortubay et al. (1994). SI: Abdominal cavity. Lo: Piedra del Águila Reservoir (40°19′S, 70°03′W), Limay River, Río Negro-Neuquen Provinces. MD: MD: MACN-Pa. DS: Larvae. Reference: Rauque et al. (2018).
Host Salmo trutta Linnaeus
SI: Corporal cavity. Lo: Pichi Picún Leufú Reservoir (40°01′S, 70°00′W); Piedra del Águila Reservoir (40°19′S, 70°03′W); Alicurá Reservoir (40°35′S, 70°50′W); Nahuel Huapi Lake (41°05′S, 71°25′W); Moreno Lake (41°04′S, 71°33′W), all Limay River, Río Negro Province. MD: MACN-Pa. DS: Larvae. Reference: Rauque et al. (2018).
Host Salvelinus fontinalis (Mitchill)
SI: Corporal cavity. Lo: Moreno Lake (41°05′S 71°30′W), Limay River, Neuquén Province. MD: MACN-Pa. DS: Larvae. Reference: Rauque et al. (2018).
Host Serrasalmus spilopleura Kner •
SI: Encysted in mesentery, wall of intestine, stomach and pyloric caecum. Lo: Riachuelo basin, Paraná River, Corrientes Province. MD: Not indicated. DS: Larvae. Reference: Hamann (1995/1996, 1999). Remarks: According to Mirande & Koerber (2020), S. spilopleura is not distributed in Argentina, but this record could correspond to Serrasalmus maculatus Kner (Jégu & Santos, 2001; Mirande & Koerber, 2020).
Host Sorubim lima (Bloch & Schneider)
SI: Free or encapsulated in abdominal cavity, mesenteries. Lo: Pilcomayo River (22°22′S, 62°32′W), Salta Province. MD: CH-N-FML# 2767. DS: Larvae. Reference: Ramallo et al. (2020).
Host Trychomycterus spegazzinii (Berg)
SI: Abdominal cavity, mesenteries. Lo: Stream afluent to Yacones River (24°31′S, 65°24′W), Salta Province. MD: UNSa-IEBI-I #052. DS: Larvae. Reference: Ailán-Choke et al. (2014).
Contracaecum jorgei Sardella, Mancini, Salinas, Simões & Luque, 2020
Host Hoplias argentinensis Rosso et al.
SI: Intestine. Lo: Pampean shallow lakes (33°25′S, 62°54′W), Unión Department, Córdoba Province. MD: (P) CHIOC # 38926. DS: Third stage larvae larvae. Reference: Sardella et al. (2020). Remarks: Contracaecum jorgei was morphologically described for adults and fourth-stage larvae (L4) found in the bird Nannopterum brasilianus and third-stage larvae (L3) found in H. argentinensis. Additionally, in the molecular analyses, sequences obtained from adult, L4 and L3 specimens of this parasite were similar and grouped, forming an independent lineage (Sardella et al., 2020).
Contracaecum rudolphii Hartwich, 1964
Synonyms: Contracaecum spiculigerum (Rudolphi, 1809); Ascaris siluriglanidis Linstow, 1883. Host Pimelodus albicans (Valenciennes) ◦ SI: Mesentery. Lo: Los Quirogas Dam (27°41′S, 64°18′W), Santiago del Estero Province. MD: Not indicated. DS: Larvae. Reference: Zeiss & Seigneur (1981).
Host Salminus brasiliensis (Cuvier) ◦
SI mesentery. Lo: Los Quirogas Dam (27°41′S, 64°18′W), Santiago del Estero Province. MD: Not indicated. DS: Larvae. Reference: Zeiss & Seigneur (1981). SI: Intestinal caecum and peritoneum of intestine. Lo: Río Hondo Reservoir (27°31′S, 64°53′W) Tucumán-Santiago del Estero Provinces. MD: CH-N-FML # 01830 and IPUAT # 0247. DS: Larvae. Reference: Ramallo & Torres (1995). Remarks: Zeiss & Seigneur (1981) also identified adults of Contracaecum rudolphii in the ventricle of Phalacrocorax brasilianus, but they did not provided morphometric characterizations of the larval stages and adult forms of this parasite. Moreover, the type specimens were not deposited in a collection. Thus, we consider that this record is doubtful and has to be carefully reviewed.
Genus Goezia Zeder, 1800
Synonyms: Cochlus Zeder, 1803; Prionoderma Rudolphi, 1808; Lecanocephalus Diesing, 1839.
Goezia sp.
Host Odontesthes bonariensis ◦
SI: Corporal cavity. Lo: Casa de Piedra Reservoir (38°10′S, 67°30′W), Río Negro-La Pampa Provinces. MD: Not indicated. DS: Not indicated. Reference: Gilbert et al. (1993), Ortubay et al. (1994). Gilbert et al. (1993) recorded Cucullanus sp. in O. mykiss and O. bonariensis from Patagonia, but these records belongs to Goezia sp. according to Ortubay et al. (1994).
Host Oncorhynchus mykiss (Walbaum) ◦
SI: Corporal cavity. Lo: Casa de Piedra Reservoir (38°10′S, 67°30′W), Río Negro-La Pampa Provinces. MD: Not indicated. DS: Not indicated. Reference: Gilbert et al. (1993), Ortubay et al. (1994). Remarks: Gilbert et al. (1993) recorded Cucullanus sp. in O. mykiss and O. bonariensis from Patagonia, but these records belongs to Goezia sp. according to Ortubay et al. (1994). Despite Ortubay et al. (1994) did not report the stage of development of this parasite, considering site of infection it can be inferred that it is a larval form in a paratenic host (Rauque et al., 2018). Odontesthes bonariensis and O. mykiss are introduced species into Patagonia, they are present in in various lakes and rivers of the Andes Mountains (Cussac et al., 2016). Thus, Goezia sp. could be considered an introduced parasite with a high specificity for O. bonariensis and O. mykiss and have not yet switched to the native fish species in Patagonia (Rauque et al., 2018).
Goezia spinulosa (Diesing, 1839)
Host Pseudoplatystoma corruscans (Spix & Agassiz) SI: Stomach. Lo: Río Paraná Medio, Corrientes Province. MD: CECOAL. DS: Adults (males, females). Reference: Hamann (1984).
Family Raphidascarididae
Genus Hysterothylacium Ward & Magath, 1916 Hysterothylacium sp.
Host Odontesthes bonariensis (Valenciennes)
SI: Mesentery. Lo: Salada Grande, General Lavalle (36°55′S, 56°58′W) and Lacombe, Lezama (35°49′S, 57°49′W) Lagoons, Buenos Aires Province. MD: CHMLP. DS: Larvae (L3). Reference: Drago (2012). Remarks: The life cycles and larval developmental of Hysterothylacium species are little known. Hysterothylacium larvae occur in Neotropical freshwater fishes serving as paratenic host (Moravec, 1998). Thus, Odontesthes bonariensis may be likely paratenic host for this parasite.
Host Odontesthes hatcheri (Eigenmann) (syn. Patagonina hatcheri)
SI: Intestine. Lo: Alicurá Reservoir (40°40′S, 71°00′W), Río Negro-Neuquén Provinces. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994). Remarks: Hysterothylacium sp. may be a new parasite species or likely, it belongs to Hysterothylacium patagonense, which was later record in Odontesthes hatcheri by Flores et al. (2016).
Host Percichthys trucha (Valenciennes)
SI: Intestine. Lo: Alicurá Reservoir (40°40′S, 71°00′W), Río Negro-Neuquén Provinces, Escondido Lake (41°05′S, 71°35′W) and Moreno Lake (41°06′S, 71°32′W), Río Negro Province. MD: Not indicated. DS: Adult. Reference: Ortubay et al. (1994).
Hysterothylacium patagonense Moravec, Urawa & Coria, 1997
Host Percichthys trucha (Valenciennes)
SI: Intestine (secondarily found in abdominal cavity). Lo: Aluminé Lake (38°55′S, 71°10′W) Negro River drainage system, Neuquen Province. MD: Type-material: IPCAS Helm. (holotype, allotype, and some paratypes, Cat. # 675); NHM (paratypes, Reg. # 1996.5.30-1-5), and Meguro Parasitological Museum, Tokyo (paratypes, Cat. # 19695). DS: Adults and third and fourth stage larvae. Reference: Moravec et al. (1997a).
Host Galaxias maculatus (Jenyns)
SI: Abdominal cavity. Lo: Quillén Lake, Neuquén; Espejo Chico Lake and Escondido lake, Río Negro Province. MD: MACN-Pa 465. DS: Larvae. Reference: Viozzi et al. (2009).
Host Odontesthes hatcheri (Eigenmann)
SI: Intestine. Lo: Morenito lake (41°02′S, 68°34′W); Moreno Oeste lake (41°06′S, 71°32′W), Río Negro Province. MD: CHMLP. DS: Fourth stage larvae. Reference: Flores et al. (2016).
Host Oncorhynchus mykiss (Walbaum)
SI: Intestine. Lo: Lake Alumine (38°55′S, 71°10′W) and Lake Huechulafquen, Negro River drainage system, Neuquen Province. MD: Not indicated. DS: Third- and fourth-stage larvae. Reference: Moravec et al. (1997a).
Host Salvelinus fontinalis (Mitchill)
SI: Intestine. Lo: Lake Alumine (38°55′S, 71°10′W), Negro River drainage system, Neuquen Province. MD: Not indicated. DS: Third- and fourth-stage larvae. Reference: Moravec et al. (1997a).
Host Salmo trutta Linnaeus
SI: Intestine. Lo: Lake Huechulafquen, Negro River drainage system, Neuquen Province. MD: Not indicated. DS: Third- and fourth-stage larvae. Reference: Moravec et al. (1997a). Remarks: According to Moravec et al. (1997a) these third- and fourth-stage larvae, like those found in O. mykiss and S. fontinalis, are morphologically and biometrically identical with those of H. patagonense from the type-host, Percichthys trucha. Moreover, since H. patagonense seems to be the only Hysterothylacium species present in Alumine and Huechulafquen lakes, the larvae were considered to belong to H. patagonense. These three salmonid species are introduced into Argentina, so apparently they can adquire infection by feeding on intermediate or paratenic hosts, but the nematode larvae cannot mature in them. Thus, salmonids may be considered paratenic hosts of this nematode species.
Hysterothylacium rhamdiae Brizzola & Tanzola, 1995
Host Rhamdia sapo (Valenciennes)
SI: Intestine. Lo: Napostá stream (38°08′S, 61°47′W); and Sauce Grande River (38°43′S, 62°15′W), Buenos Aires Province. MD: Holotype and allotype MACN # 373, and paratypes Laboratorio de Parasitología, Depto. Biología y Bioquímica, Universidad Nacional del Sur # 001-004. DS: Adults (males, females). Reference: Brizzola & Tanzola (1995).
Genus Raphidascaris Railliet & Henry, 1915
Synonyms: Ichthyascaris Wu, 1949; Neogoezia Kreis, 1937; Sprentascaris Petter & Cassone, 1984.
Subgenus Sprentascaris Petter & Cassone, 1984
Raphidascaris (Sprentascaris) marano Ramallo, 2009
Host Hypostomus cordovae (Günther)
SI: Intestine. Lo: Marapa River (27°37′S, 65°41′W), Tucumán Province. MD: Holotype CH-N-FML # 07462-A; allotype CH-N-FML # 07462-B, and paratypes CH-NFML # 07463. DS: Adults. Reference: Ramallo (2009).
Raphidascaris (Sprentascaris) saltaensis Ailán Choke, Ramallo & Davies, 2017
Host Rineloricaria steinbachii (Regan) (syn. Loricaria steinbachii)
SI: Intestine. Lo: La Caldera River (24°35′S, 65°22′W), Salta Province. MD: Holotype: female CH-N-FML #07663; Allotype: not assigned; Paratypes CH-N-FML # 07665. DS: Adults. Reference: Ailán-Choke et al. (2017).
Superfamily Seuratoidea
Family Cucullanidae
Genus Cucullanus Müller, 1777
Subgenus Cucullanus Müller, 1777
Cucullanus (Cucullanus) pauliceae Vaz & Pereira,
1934
Host Zungaro zungaro (Humboldt) [syn. Paulicea luetkeni (Steindachner)] •
SI: Small and large intestine. Lo: Paraná Medio River, Corrientes Province. MD: CECOAL. DS: Adults. Reference: Hamann (1984). Remarks: Host originally reported as Paulicea lutkeni (synonym of Z. zungaro). According to Mirande & Koerber (2020), Z. zungaro is not distributed in Argentina. Probably, due to similarity among them, the original record of P. lutkeni by Hamann (1984) corresponds to Zungaro jahu, which inhabit in the Parana River basin.
Cucullanus (Cucullanus) pinnai pinnai Travassos, Artigas & Pereira, 1928
Host Heptapterus mustelinus (Valenciennes)
SI: Stomach. Lo: El Tunal Dam (25°15′S, 64°25′W), Salta Province. MD: Not indicated. DS: Adults. Reference: Cancino & Ramallo (2008).
Host Jenynsia alternimaculata (Fowler)
SI: Intestine. Lo: Strem affluent of Yacones River (24°31′S, 65°24′W), Isasmendi Stream (24°48′S, 64°26′W), Salta Province. MD: CH-N-FML # 7512, UNSa-IEBI-I # 050. DS: Adults. Reference: Ailán-Choke et al. (2014).
Host Luciopimelodus pati (Valenciennes)
SI: Intestine. Lo: Río Paraná Medio, Corrientes Province. MD: Not indicated. DS: Adults and third- and fourth-stage larvae. Reference: Hamann (1985).
Host Pimelodus maculatus Lacepède [syn. Pimelodus clarias (Linnaeus)].
SI: Intestine. Lo: Río Paraná Medio, Corrientes Province. MD: Not indicated. DS: Adults and third- and fourth-stage larvae. Reference: Hamann (1985). SI: Intestine. Lo: San Javier River (31°13′S, 60°10′W), Cayastá; Feller Lagoon (31°01′S, 60°01′W); San Javier River, Helvecia, Santa Fé Province. MD: MFA-ZI-N-233. DS: Adults. Reference: Chemes & Takemoto (2020).
Host Pimelodus albicans (Valenciennes)
SI: Intestine. Lo: Paraná Medio River, Corrientes Province. MD: Not indicated. DS: Adults. Reference: Hamann (1985). SI: Intestine. Lo: Río Hondo Reservoir (27°31′S, 64°53′W), Santiago del Estero-Tucuman Provinces. MD: CH-N-FML # 01840. DS: Adults. Reference: Ramallo (1999). SI: Stomach. Lo: Pilcomayo River (22°22′S, 62°32′W), Salta Province. MD: CHN-FML # 7775. DS: Adults. Reference: Ramallo et al. (2020).
Host Pseudoplatystoma corruscans (Spix & Agassiz)
SI: Intestine. Lo: Río Paraná Medio, Corrientes Province. MD: Not indicated. DS: Adults and third- and fourth-stage larvae. Reference: Hamann (1985).
Host Trichomycterus spegazzinii (Berg) **
SI: Intestine. Lo: Strem affluent of Yacones River (24°31′S, 65°24′W), Isasmendi Stream (24°48′S, 64°26′W), Salta Province. MD: UNSa-IEBI-I # 050. DS: Adults. Reference: Ailán-Choke et al. (2014). SI: Intestine. Lo: La Caldera River (24°35′S, 65°22′W), Yacones River (24°40′S, 65°24′W) Salta Province. MD: UNSa-IEBI-I # 060. DS: Adults. Reference: Present study. Remarks: New locality record.
Genus Dichelyne Jägerskiöld, 1902
Subgenus Cucullanellus (Tornquist, 1931)
Dichelyne (Cucullanellus) mariajuliae Alarcos et al., 2006
Host Pogonias cromis (Linnaeus)
SI: Middle and posterior intestine. Lo: Mar Chiquita coastal lagoon (37°32′S, 57°19′W), Buenos Aires Province. MD: (H) CHMLP # 5520; (A) CHMLP # 5521; (P) CHMLP # 5522. DS: Adults (males and females). Reference: Alarcos et al. (2006).
Genus Neocucullanus Travassos, Artigas & Pereira,
1928
Neocucullanus marcelae Ramallo, 2012
Host Salminus brasiliensis (Cuvier, 1816)
SI: Intestine, pyloric caeca and liver. Lo: El Chorro, Juramento River (25°13′S, 64°28′W), Salta Province. MD: (H): CH-N-FML# 07488; (A): CH-N-FML #07489; (P) CH-N-FML # 07490. DS: Adults. Reference: Ramallo (2012).
Order Spirurida
Superfamily Camallanoidea
Family Camallanidae
Genus Camallanus Railliet & Henry, 1915
Synonym: Zeylanema Yeh, 1960
Subgenus Zeylanema Yeh, 1960
Camallanus (Zeylanema) corderoi Torres, Teuber &
Miranda, 1990
Host Galaxias maculatus (Jenyns)
SI: Intestine. Lo: Nahuel Huapi Lake (41°03′S, 71°25′W), Neuquén and Río Negro Provinces. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994). SI: Intestine. Lo: Moreno Lake (41°04′S, 71°33′W), Neuquen Province. MD: Not indicated. DS: Not indicated. Reference: Rauque et al. (2003). SI: Intestine. Lo: Senillosa Channel (Limay River) (38°50′S, 68°30′W); Lakes: Ñorquinco (39°09′S, 71°17′W), Huechulafquén (39°45′S, 71°25′W), Morenito (41°05′S, 71°31′W), and Escondido (41°05′S, 71°35 W); and Caleufu River (40°30′S, 71°17′W), Patagonia. MD: MACN-Pa 463. DS: Larvae. Reference: Viozzi et al. (2009). SI: Intestine. Lo Nahuel Huapi Lake (41°04′S, 71°25′W), Neuquén and Río Negro Provinces. MD: Not indicated. DS: Larvae. Reference: Fernandez et al. (2015). Remarks: The records of Camallanus (Zeylanema) corderoi larvae has to be carefully reviewed, because their morphology does not enable to identify them to species. Camallanus (Zeylanema) corderoi is a common parasite of Percichthys trucha. According to Rauque et al. (2018), C. corderoi uses the native G. maculatus as intermediate host and the native P. trucha as definitive.
Host Galaxias platei Steindachner
SI: Intestine. Lo: Ezquerra Lagoon (41°03′S, 71°33′W), Río Negro Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994). SI: Intestine. Lo: Moreno Lake (41°04′S, 71°33′W), Neuquen Province. MD: Not indicated. DS: Not indicated. Reference: Rauque et al. (2003).
Host Jenynsia multidentata (Jenyns)
SI: Intestine. Lo: Arroyón Stream (38°43.66′S 68°02.4′W), Neuquén River, Neuquén Province. MD: MACN–Pa 657/1. DS: non-gravid adults. Reference: Rauque et al. (2018).
Host Odontesthes bonariensis (Valencienne)
SI: Intestine. Lo: Pellegrini Lake (38°41′S, 68°00′W), Neuquén River, Neuquén Province. MD: MACN–Pa 657/1. DS: gravid adults. Reference: Rauque et al. (2018).
Host Odontesthes hatcheri (Eigenmann) (syn. Patagonina hatcheri).
SI: intestine. Lo: Alicurá Reservoir, Río Negro-Neuquén Provinces, Pellegrini Lake, Río Negro Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al., 1994. SI: Intestine. Lo: Marimenuco Reservoir (38°32′S, 69°25′W), Neuquén province; Lezana Lake (42°27′S, 71°29′W) and Musters Lake (45°25′S, 69°11′W), Chubut Province; Morenito lake (41°02′S, 68°34′W) and Moreno Oeste Lake (41°06′S, 71°32′W), Río Negro Province. MD: CHMLP. DS: Adults. Reference: Flores et al. (2016).
Host Oncorhynchus mykiss (Walbaum)
SI: intestine. Lo: Alicurá Reservoir (40°40′S, 71°00′W), Río Negro-Neuquén Provinces. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994). SI: Intestine. Lo: Moreno Lake (41°04′S, 71°33′W), Neuquen Province. MD: Not indicated. DS: Not indicated. Reference: Rauque et al. (2003). SI: Intestine. Lo: El Chañar Reservoir (38°34.5′S, 68°24′W), Neuquén River; Escondido Lake (41°42′S, 71°38′W), Morenito Lake (41°03′S 71°31′W), Moreno Lake (41°05′S, 71°30′W), Nahuel Lake (41°05′S, 71°20′W), Ramos Mexía Reservoir (39°26′S, 68°56′W), downstream Arroyito Dam (39°04.5′S, 68°33′W), all Limay River, Río Negro Province. MD: MACN–Pa 657/1. DS: non-gravid adults. Reference: Rauque et al. (2018).
Host Percichthys trucha (Valenciennes)
SI: Stomach, intestine, pyloric caecum. Lo: Moreno (41°06′S, 71°32′W) and Pellegrini (38°40′S, 68°00′W) Lakes, Ezquerra Lagoon (41°03′S, 71°33′W); Casa de Piedra Stream (38°10′S, 67°30′W) and Alicurá Reservoir (40°40′S, 71°00′W), Río Negro-Neuquén Provinces. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994) and Rauque et al. (2003).
Host Salmo salar Linnaeus
SI: Intestine. Lo: Alicurá Reservoir (40°35′S, 70°50′W), Limay River, Río Negro Province. MD: MACN–Pa 657/1. DS: non-gravid adults. Reference: Rauque et al. (2018).
Host Salmo trutta Linnaeus
SI: Intestine. Lo: Moreno Lake (41°05′S, 71°30′W); Gutiérrez Lake (41°12′S, 71°24.5′W), Nahuel Huapi Lake (41°05′S, 71°20′W), Alicurá Reservoir (40°35′S, 70°50′W), Piedra del Águila Reservoir (40°19′S, 70°03′W), Pichi Picún Leufú Reservoir (40°01′S, 70°00′W), all Limay River, Río Negro Province. MD: MACN–Pa 657/1. DS: non-gravid adults. Reference: Rauque et al. (2018).
Host Salvelinus fontinalis (Mitchill)
SI: Intestine. Lo: General Vintter Lake (43°52′S, 71°30′W) and Corcovado River (40°40′S, 71°00′W), Chubut Province. MD: Not indicated. DS: Not indicated. Reference: Úbeda et al. (1989). SI: Intestine. Lo: Moreno Lake (41°04′S, 71°33′W), Neuquen Province. MD: Not indicated. DS: Not indicated. Reference: Rauque et al. (2003). SI: Intestine. Lo: Moreno Lake (41°05′S, 71°30′W), Limay River, Río Negro Province. MD: MACN–Pa 657/1. DS: non-gravid adults. Reference: Rauque et al. (2018).
Subgenus Camallanus Railliet & Henry, 1915
Camallanus (Camallanus) tridentatus (Drasche, 1884)
Synonym: Cucullanus tridentatus Drasche, 1884
Host Oncorhynchus mykiss (Walbaum) ◦
SI: Intestine. Lo: Lezama Lake, Chubut Province. MD: Not indicated. DS: Adults. Reference: Úbeda et al. (1989).
Host Percichthys colhuapiensis MacDonagh SI: Not indicated. Lo: Ezequiel Ramos Mexia Reservoir (39°30′S, 69°00′W), Río Negro-Neuquén Provinces. MD: Not indicated. DS: Not indicated. Reference: Ortubay et al. (1994).
Host Percichthys trucha (Valenciennes) ◦
SI: Pyloric caecum, small intestine and stomach. Lo: Pellegrini Lake (38°40′S, 68°00′W), Río Negro Province. MD: Not indicated. DS: Adults. Reference: Szidat (1956). SI: Intestine and stomach. Lo: Mosquito Lagoon and Lezama Lake, Chubut Province. MD: Not indicated. DS: Adults. Reference: Úbeda et al. (1989).
Host Salvelinus fontinalis (Mitchill) ◦
SI: Intestine. Lo: Winter Lake and Corcovado River, Chubut Province. MD: Not indicated. DS: Adults. Reference: Úbeda et al. (1989). Remarks: According to Ortubay et al. (1994), C. tridentatus reported on O. mykiss, P. trucha, and S. fontinalis (Úbeda et al., 1989), was misidentified and could correspond to Camallanus corderoi.
Genus Procamallanus Baylis, 1923
Subgenus Denticamallanus Moravec & Thatcher, 1997
Procamallanus (Denticamallanus) ana Ramallo, 2011
Host Thoracocharax stellatus (Kner)
SI: Intestine. Lo: Teuquito River (24°12′S, 62°54′W), Salta Province. MD: (H) CH-N-FML # 07475; (A) CH-NFML # 07476, and (P) CH-N-FML # 07477. DS: Adults. Reference: Ramallo (2011).
Genus Spirocamallanus Olsen, 1952
Spirocamallanus hilarii Vaz & Pereira, 1934
Synonyms: Procamallanus cearensis Pereira, Dias & Azevedo, 1936; Spirocamallanus incarocai Freitas & Ibañez, 1970.
Host Astyanax abramis (Jenyns)
SI: Intestine and stomach. Lo: (27°33′S, 64°57′W), Tucumán and Santiago del Estero Provinces. MD: Not indicated. DS: Adults. Reference: Ramallo (2005a).
Host Astyanax bimaculatus (Linnaeus)
SI: Intestine and stomach. Lo: Escaba Dam (27°42′S, 64°48′W), Río Hondo Reservoir (27°33′S, 64°57′W), Tucumán and Santiago del Estero Provinces. MD: CHN-FML # 04018 for record from Escaba Dam. DS: Adults. Reference: Ramallo (2005a). SI: Intestine and stomach. Lo: El Tunal Reservoir (25°14′S, 64°31′W), Salta Province. MD: Not indicated. DS: Adults. Reference: Cancino & Ramallo (2008). SI: Intestine and stomach. Lo: Itaú River (22°20′S, 64°05′W). MD: CHN-FML #07480. DS: Adults. Reference: Antelo et al. (2016). Remarks: Host originally reported as Astyanax bimaculatus, but according to Lucena & Soares (2016) the material identified as A. bimaculatus corresponds to A. lacustris.
Host Bryconamericus thomasi Fowler (syn. Piabina thomasi) **
SI: Intestine. Lo: Itaú River (22°20′S, 64°05′W), Salta Province. MD: Not indicated. DS: Adults. Reference: Antelo et al. (2016). SI: Intestine. Lo: Arias River (24°47′S, 65°28′W), Arias-Arenales River (24°48′S, 65°25′W), San Lorenzo River (24°47′S, 65°28′W), Salta Province. MD: UNSa-IEBI-I # 0051. DS: Adults. Reference: Present study. Remarks: new locality records.
Host Psalidodon anisitsi (Eigenmann) (syn. Hyphessobrycon anisitsi)
SI: Intestine. Lo: Salado River (28°48′S, 62°39′W), Añatuya, General Taboada Department, Santiago del Estero Province. MD: CH-N-FML # 7732. DS: Adults. Reference: Ramallo & Ailán-Choke (2017).
Host Hoplias misionera Rosso et al.
SI: Intestine and stomach. Lo: Río Hondo Reservoir (27°31′S, 64°53′W), Tucumán-Santiago del Estero Provinces. MD: Not indicated. DS: Adults. Reference: Ramallo (1997).
Host Jenynsia alternimaculata (Fowler)
SI: Intestine. Lo: Isasmendi Stream (24°48′S, 65°26′W); Yacones River (24°40′S, 65°24′W), Salta Province. MD: CH-N-FML # 7513; UNSa-IEBI-I # 0051. DS: Adults. Reference: Ailán-Choke et al. (2014).
Host Megaleporinus obstusidens Valenciennes (syn. Leporinus obtusidens)
SI: Intestine and stomach. Lo: Río Hondo Reservoir (27°31′S, 64°53′W), Tucumán-Santiago del Estero Provinces. MD: Not indicated. DS: Adults. Reference: Ramallo (1997).
Host Oligosarcus jenynsii (Günther)
SI: Intestine and stomach. Lo: Río Hondo Reservoir (27°31′S, 64°53′W), Tucumán-Santiago del Estero Provinces. MD: Not indicated. DS: Adults. Reference: Ramallo (1997).
Host Pimelodus albicans (Valenciennes)
SI: Intestine and stomach. Lo: Río Hondo Reservoir (27°31′S, 64°53′W), Tucumán-Santiago del Estero Provinces. MD: CH-N-FML # 01937. DS: Adults. Reference: Ramallo (1997).
Host Psalidodon eigenmanniorum (Cope) (syn. Astyanax eigenmanniorum) ***
SI: Intestine. Lo: Arias River (24°47′S, 65°28′W), Arias-Arenales River (24°48′S, 65°25′W), San Lorenzo River (24°47′S, 65°28′W), Salta Province. MD: UNSa-IEBI-I # 0051. DS: Adults. Reference: Present study. Remarks: New host and locality records.
Host Psalidodon endy (Mirande, Aguilera & Azpelicueta) (syn. Astyanax endy) ***
SI: Intestine. Lo: La Caldera River (24°35′S, 65°22′W), La Calderilla Stream (24°39′S, 65°22′W), Campo Alegre Dam (24°34′S, 65°21′W) Salta Province. MD: UNSaIEBI-I N°0051. DS: Adults. Reference: Present study. Remarks: New host and locality records.
Host Psalidodon rutilus (Jenyns) [syn. Astyanax fasciatus (non Cuvier, 1819)]
SI: Intestine and stomach. Lo: Río Hondo Reservoir (27°33′S, 64°57′W), Tucumán and Santiago del Estero Provinces. MD: CH-N-FML # 07426. DS: Adults. Reference: Ramallo (2005a).
Host Salminus brasiliensis (Cuvier) **
SI: Intestine and stomach. Lo: Río Hondo Reservoir (27°31′S, 64°53′W), Tucumán-Santiago del Estero Provinces. MD: CH-N-FML #01301. DS: Adults. Reference: Ramallo (1997). SI: Intestine. Lo: Juramento River (25°13′S, 64°28′W), Salta Province. MD: CH-NFML #07800 and 07801. DS: Adults. Reference: Present study. Remarks: New locality record.
Host Trichomycterus spegazzini (Berg) ***
SI: Intestine. Lo: La Caldera River (24°35′S, 65°22′W), Salta Province. MD: UNSa-IEBI-I # 0051. DS: Adults. Reference: Present study. Remarks: New host and locality records.
Spirocamallanus huacraensis Ramallo, 2008.
Host Trichomycterus corduvensis Weyenbergh
SI: Intestine. Lo: Huacra River (28°00′S, 65°33′W), Catamarca Province. MD: (H) CH-N-FML #07432, (A) CH-N-FML # 07431, (P) CH-N-FML #07433. DS: Adults. References: Ramallo (2008). SI: Intestine. Lo: Vis-Vis River (27°15′S, 66°35′W), Catamarca Province. MD: CH-N-FML # 07478. DS: Adults. Reference: Ramallo & Padilla Bortayro (2011).
Host Trichomycterus spegazzinii (Berg)
SI: Intestine. Lo: Escoipe River (25°06′S, 65°36′0.4” W) Salta. MD: MACN-Pa N°662. DS: Adults. Reference: Ailán-Choke et al. (2019).
Spirocamallanus inopinatus Travassos, Artigas & Pereira, 1928
Synonyms: Procamallanus fariasi Pereira, 1935; P. wrighti Pereira, 1935; P. probus Pinto & Fernandes, 1972.
Host Brycon orbignyanus (Valenciennes)
SI: Intestine. Lo: Middle Paraná River and Santa Lucía River, Corrientes Province. MD: Not indicated. DS: Not indicated. Reference: Hamann (1986).
Host Poptella paraguayensis (Eigenmann) (syn. Ephyppicharax orbicularis paraguayensis)
SI: Intestine. Lo: Middle Paraná River and Santa Lucía River, Corrientes Province. MD: Not indicated. DS: Not indicated. Reference: Hamann (1986).
Host Hoplias misionera Rosso et al.
SI: Intestine. Lo: Pilcomayo River (22°22′S, 62°32′W) Rivadavia Department, Salta Province. MD: CH-N-FML # 7776. DS: Adults. Reference: Ramallo et al. (2020).
Host Megaleporinus obtusidens (Valenciennes)
SI: Intestine. Lo: Middle Paraná River and Santa Lucía River, Corrientes Province. MD: Not indicated. DS: Not indicated. Reference: Hamann (1986).
Host Leporinus maculatus Müller & Troschel •
SI: Intestine. Lo: Midle Paraná River and Santa Lucía River, Corrientes Province. MD: Not indicated. DS: Not indicated. Reference: Hamann (1986). Remarks: Leporinus maculatus is not occurring in Argentina (Mirande & Koerber, 2020), but according to Braga (1993) and López et al. (2003), the records of this species could correspond to Leporinus acutidens.
Host Luciopimelodus pati (Valenciennes)
SI: Intestine. Lo: Midle Paraná River and Santa Lucía River, Corrientes Province. MD: Not indicated. DS: Not indicated. Reference: Hamann (1986).
Host Pimelodus maculatus Lacépède
SI: Intestine. Lo: Coronda River (31°41′S, 60°44′W), Santo Tomé, Santa Fé Province. MD: MFA-ZI-N-232. DS: Only one male. Reference: Chemes & Takemoto (2020).
Host Pseudoplatystoma corruscans (Spix & Agassiz)
SI: Intestine. Lo: Middle Paraná River and Santa Lucía River, Corrientes Province. MD: Not indicated. DS: Not indicated. Reference: Hamann (1986).
Host Pygocentrus nattereri Kner (syn. Serrasalmus nattereri).
SI: Intestine. Lo: Perez and Totora Lagoons, Riachuelo Basin, Corrientes Province. MD: Not indicated. DS: Not indicated. Reference: Hamann (1986).
Host Serrasalmus marginatus Valenciennes SI: Intestine. Lo: Perez and Totora Lagoons, Riachuelo Basin, Corrientes Province. MD: Not indicated. DS: Not indicated. Reference: Hamann (1986).
Host Serrasalmus spilopleura Kner •
SI: Intestine. Lo: Perez and Totora Lagoons, Riachuelo Basin, Corrientes Province. MD: Not indicated. DS: Not indicated. Reference: Hamann (1986). Remarks: According to Mirande & Koerber (2020), S. spilopleura is not present in Argentina, but this record could correspond to Serrasalmus maculatus Kner (Jégu & Santos, 2001; Mirande & Koerber, 2020).
SI: Intestine. Lo: Aeroclub and Ramada Lagoons, Riachuelo River basin, Corrientes Province. MD: Not indicated. DS: Adults. Reference: Hamann (1995/1996).
Spirocamallanus juana Ramallo & Ailán Choke, 2017
Host Pimelodus albicans (Valenciennes)
SI: Intestine. Lo: Salado River (28°48′S, 62°39′W) Santiago del Estero Province. MD: (H) CH-N-FML # 07729; (A) CH-N-FML # 07730; (P) CH-N-FML # 07731. DS: Adults. Reference: Ramallo & Ailán-Choke (2017).
Host Pimelodella gracilis (Valenciennes) SI: Intestine. Lo: Salado River (28°48′S, 62°39′W) Santiago del Estero Province. MD: Not indicated. DS: Adults. Reference: Ramallo & Ailán-Choke (2017).
Spirocamallanus neocaballeroi (Caballero-Deloya, 1977)
Host Pimelodus maculatus Lacépède
SI: Intestine. Lo: lag Feller Lagoon (31°01′S, 60°01′W), San Javier River, Helvecia, Santa Fé Province. MD: MFA-ZI-N-231. DS: Only one male. Reference: Chemes & Takemoto (2020).
Spirocamallanus pimelodus Pinto, Fábio, Noronha & Rolas, 1974
Synonym: Procamallanus intermedius Pinto, Fábio, Noronha & Rolas, 1974.
Host Pimelodus maculatus Lacépède
SI: Intestine. Lo: Feller Lagoon (31°01′S, 60°01′W), San Javier River, Helvecia, Santa Fé Province. MD: MFA-ZI-N-234. DS: Adults. Reference: Chemes & Takemoto (2020).
Spirocamallanus pintoi (Kohn & Fernandes, 1988)
Host Trichomycterus spegazzinii (Berg)
SI: Intestine. Lo: Isasmendi Stream (24°48′S, 65°26′W), Salta Province. MD: CH-N-FML #7515. DS: Adult. Reference: Ailán-Choke et al. (2014).
Host Corydoras paleatus (Jenyns)
SI: Intestine. Lo: Arias-Arenales River (24°48′S, 65°25′W) and Arias River (24°47′S, 65°28′W) Salta Province. MD: CH-FML # 7739. DS: Adults. Reference: Ailán-Choke et al. (2018).
Host Corydoras micracanthus Regan
SI: Intestine. Lo: Yacones River (24°40′S, 65°24′W) and Lesser River (24°39′S, 65°28′W), Salta Province. MD: CH-FML # 7740. DS: Adults. Reference: Ailán-Choke et al. (2018).
Spirocamallanus rarus Travassos, Artigas & Pereira, 1928
Synonym: Spirocamallanus rarus Olsen, 1952
Host Pimelodus albicans (Valenciennes)
SI: Small and large intestine. Lo: Middle Paraná River, Corrientes Province. MD: CECOAL. DS: Adults. Reference: Hamann (1984).
Spirocamallanus tomsici Ramallo & Ailán Choke, 2020
Host Pimelodus albicans (Valenciennes)
SI: Intestine. Lo: Misión La Paz, Pilcomayo River (22°22′S, 62°32′W), Rivadavia Department, Salta Province. MD: (H) CH-N-FML #07766; (A) CH-NFML # 07767; (P) CH-N-FML # 07768. DS: Adults. Reference: Ramallo et al. (2020).
Host Pygocentrus nattereri Kner
SI: Intestine. Lo: Misión La Paz, Pilcomayo River (22°22′S, 62°32′W), Rivadavia Department, Salta Province. MD: CH-N-FML #07788. DS: Adults. Reference: Ramallo et al. (2020).
Host Hoplias misionera Rosso et al.
SI: Intestine. Lo: Misión La Paz, Pilcomayo River (22°22′S, 62°32′W), Rivadavia Department, Salta Province. MD: CH-N-FML # 7789. DS: Adults. Reference: Ramallo et al. (2020).
Superfamily Cosmocercoidea
Family Atractidae
Genus Klossinemella Costa, 1961
Klossinemella iheringi (Travassos, Artigas & Pereira,
1928)
Synonym: Monhysterides iheringi Travassos, Artigas & Pereira, 1928
Host Pterodoras granulosus (Valenciennes) SI: Intestine. Lo: Paraná River, Corrientes Province. MD: CECOAL. DS: Adults. Reference: Hamann (1982b).
Genus Rondonia Travassos, 1920
Rondonia rondoni Travassos, 1920
Host Piaractus mesopotamicus (Holmberg) [syn. Colossoma mitrei (Berg)].
SI: Intestine. Lo: Paraná Medio River, Corrientes Province. MD: CECOAL. DS: Adults. Reference: Hamann (1982a).
Host Pterodoras granulosus (Valenciennes)
SI: Intestine. Lo: Parana Medio River, Corrientes Province. MD: CECOAL. DS: Adults. Reference: Hamann (1982b).
Family Kathlaniidae
Genus Spectatus Travassos, 1923
Spectatus spectatus Travassos, 1923
Host Piaractus mesopotamicus (Holmberg) (syn. Colossoma mitrei).
SI: Intestine. Lo: Paraná Medio River, Corrientes Province. MD: CECOAL. DS: Adults. Reference: Hamann (1982a).
Host Pterodoras granulosus (Valenciennes) SI: Intestine. Lo: Paraná Medio River, Corrientes Province. MD: CECOAL. DS: Adults. Reference: Hamann (1982b).
Superfamily Dracunculoidea
Family Guyanemidae
Genus Pseudodelphis Adamson & Roth, 1990
Pseudodelphis limnicola Brugni & Viozzi, 2006
Host Percichthys trucha (Valenciennes)
SI: Sinus venosus and atrium, intestine, and abdominal cavity. Lo: Lake Escondido (41°05′S, 71°35′W), Nahuel Huapi National Park, Río Negro Province. MD: MACNPa (H) # 429/1; (A) # 429/2, (P) # 429/3–6 and 429/7–10; CHMLP (P) # 5519; UNCo-Pa (P) # 201/1–10 and (P) 201/11–20) and IPCAS Helm. (P) # N833 (1 male and 1 female). DS: Adult males and gravid females, larvae and sub-adults. Reference: Brugni & Viozzi (2006).
Family Philometridae
Genus Philonema Kuitunen-Ekbaum, 1933
Synonym: Coregonema Bauer, 1946
Philonema percichthydis Moravec, Urawa & Coria, 1997
Host Percichthys trucha (Valenciennes)
SI: Abdominal cavity. Lo: Lago Aluminé, (38°55′S, 71°10′W), Río Negro basin, Río Negro Province. MD: IPCAS Helm. (holotype and remnants of paratypes, Cat. # N-690. DS: Two gravid females. Reference: Moravec et al. (1997b).
Superfamily Habronematoidea Family Cystidicolidae
Genus Ascarophis van Beneden, 1871
Synonyms: Capillospirura Skrjabin, 1924; Pseudocystidicola Layman, 1933
Ascarophis patagonica Brugni & Viozzi, 2008
Host Galaxias platei Steindachner
SI: Stomach. Lo: Moreno Lake (41°05′S, 71°32′W), Coyte Pond (45°25′S, 71°22′W), Río Negro Province. MD: MACN (H) # 442/1, (A) # 442/2, (P) #442/3-7 and # 442/8-12; CPUNCo (P) #5756; CHMLP (P) # 215/1-7 and # 215/8-14 and USNPC (P) #100568. DS: Males and gravid females. Reference: Brugni & Viozzi (2008).
Genus Placonema Brugni, Viozzi, Fernández & Vega, 2009
Placonema pataguense Brugni, Viozzi, Fernández & Vega, 2009
Host Galaxias maculatus (Jenyns)
SI: Stomach. Lo: Patagua Lake (40°47′S, 71°37′W), Arrayanes National Park, Río Negro Province. MD: MACN-Pa: (H) male # 446/1), (A) female # 446/2, and (P) # 446/3–5 and # 446/6–8. USNPC (P) #101088, # 101090, #101087, # 101089). UNC (P) # 216/1–5 and # 216/6–12. MLP (P) # 5865. DS: Adults. Reference: Brugni et al. (2009).
Genus Spinitectus Fourment, 1883
Spinitectus asperus Travassos, Artigas & Pereira, 1928
Synonym: Spinitectus jamundensis Thatcher & Padilha, 1977
Host Prochilodus lineatus (Valenciennes) (syn. P. platensis Holmberg)
SI: Stomach. Lo: Middle Paraná River, Corrientes Province. MD: CECOAL. DS: male and gravid females. Reference: Hamann (1982c). SI: Cardial stomach. Lo: Río Hondo Reservoir (27°31′S, 64°53′W), Tucumán-Santiago del Estero Provinces. MD: CH-N-FML # 01298. DS: males, gravid females and larvae. Reference: Ramallo (1999). SI: Cardial stomach. Lo: Misión La Paz, Pilcomayo River (22°22′S, 62°32′W), Rivadavia Department, Salta Province. MD: CH-N-FML #07773. DS: Adults. Reference: Ramallo et al. (2020).
Host Pimelodus albicans (Valenciennes)
SI: Posterior intestine. Lo: Río Hondo Reservoir (27°31′S, 64°53′W), Tucumán-Santiago del Estero Provinces. MD: Not indicated. DS: Adults. Reference: Ramallo (1999).
Host Megaleporinus obstusidens Valenciennes
SI: Posterior intestine. Lo: Río Hondo Reservoir (27°31′S, 64°53′W), Tucumán-Santiago del Estero Provinces. MD: Not indicated. DS: Adults. Reference: Ramallo (1999).
Family Hedruridae
Genus Hedruris Nitzsch, 1821
Hedruris sp.
Host Galaxias maculatus (Jenyns)
SI: Abdominal cavity. Lo: Moreno Lake (41°03′S 71°31′W), Río Negro Province. MD: Not indicated. DS: Larvae. Reference: Revenga et al. (2005). SI: Stomach. Lo: Lakes Ñorquinco (39°09′S, 71°17′W), Quillén (39°25′S, 71°20′W), Tromen (39°32′S, 71°28′W); Machónico (40°20′S, 71°33′W), Hermoso (40°21′S, 71°28′W), Pudú Pudú (40°23′S, 71°28′W), Villarino (40°28′S, 71°35′W), Falkner (40°29′S, 71°29′W), Filo Hua Hum (40°30′S, 71°17′W), Espejo Chico (40°35′S, 71°44′W), Traful (40°37′S, 71°25′W), Espejo (40°41′S, 71°40′W), Correntoso (40°44′S, 71°39′W), Patagua (40°47′S, 71°37′W), Morenito (41°05′S, 71°31′W); Mascardi (41°17′S, 71°38′W), Fonck (41°18′S, 71°43′W), Hess (41°22′S, 71°43′W), Steffen (41°31′S, 71°33′W), Patagonia. MD: MACN-Pa 466. DS: Adults. Reference: Viozzi et al. (2009).
Host Galaxias platei Steindachner
SI: Not indicated. Lo: Lagoons: Zeta (42°53′S, 71°20′W), Caradogh Jones (42°54′S, 71°23′W), Huillimanco (42°52′S, 71°17′W); Rosario Lake (43°15′S, 71°20′W), Chubut Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994). SI: Stomach. Lo: Lakes: Cholila (42°27′S, 71°40′W), and Esperanza (42°13′S, 71°50′W), Chubut Province, and Pueyrredón Lake (47°16′S, 72°00′W), Santa Cruz Province; Lagoons: Huillimanco (42°52′S, 71°50′W), and La Pava, Chubut Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994).
Host Oncorhynchus mykiss (Walbaum)
SI: Stomach, intestine, pyloric caecum. Lo: Casa de Piedra (38°10′S, 67°30′W) Stream, Ñireco River (41°14′S, 71°11′W), Limay River and Nahuel Huapi Lake (41°03′S, 71°25′W), Río Negro Province. MD: Not indicated. DS: Adults and larvae. Reference: Ortubay et al. (1994). SI: Not indicated. Lo: Ñireco River (41°14′S, 71°11′W), Río Negro Province; Traful Lake (40°37′S, 71°25′W), Neuquén Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994).
Host Percichthys trucha (Valenciennes)
SI: Stomach. Lo: Ñireco River, Río Negro Province. MD: Not indicated. DS: Adults and larvae. Reference: Ortubay et al. (1994). SI: Stomach. Lo: Moreno Lake (42°27′S, 71°40′W), Río Negro Province; Cholila Lake (42°27′S, 71°40′W), Chubut Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994).
Host Salmo trutta Linnaeus
SI: Stomach. Lo: Hess Lake (41°22′S, 71°43′W), Río Negro Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994). SI: Stomach. Lo: Limay River (41°22′S, 71°43′W), Río Negro-Neuquén Provinces. MD: Not indicated. DS: Adults and larvae. Reference: Ortubay et al. (1994). Remarks: Rauque et al. (2018) mentioned that records of Hedruris sp. in O. mykiss, S. trutta, G. maculatus, G. platei and P. trucha, could correspond to Hedruris suttonae.
Hedruris bifida Rossin & Timi, 2016
Host Oligosarcus jenynsii (Günther)
SI: Females attached to stomach wall and males generally found encircling female. Lo: Lake Nahuel Rucá (37°37′S, 57°26′W), Buenos Aires Province. MD: (H) (MLP-He coll. # 7159), (A) (MLP-He coll. # 7160) and (P) MLP-He coll. # 7161. DS: Adults (males and females). Reference: Rossin & Timi (2016).
Hedruris suttonae Brugni & Viozzi, 2010
Host Galaxias maculatus (Jenyns)
SI: Stomach. Lo: Lakes: Moreno (41°03′S, 71°31′W), Ñorquinco (39°09′S, 71°17′W), Quillén (39°25′S, 71°25′W), Tromen (39°32′S, 71°27′W), Machónico (40°21′S, 71°26′W), Pudú Pudú (40°23′S, 71°28′W), Hermoso (40°23′S, 71°29′W), Villarino (40°28′S, 71°35′W), Falkner (40°29′S, 71°29′W), Filo Hua Hum (40°30′S, 71°17′W), Traful (40°37′S, 71°25′W), Espejo (40°41′S, 71°40′W), Espejo Chico (40°41′S, 71°42′W), Correntoso (40°44′S, 71°39′W), Nahuel Huapi (40°48′S, 71°39′W), Patagua (40°51′S, 71°50′W), Moreno (41°03′S, 71°31′W), Mascardi (41°17′S, 71°38′W), Fonck (41°19′S, 71°45′W), Hess (41°23′S, 71°43′W), Steffen (41°31′S, 71°33′W), Patagonia. MD: MACN-Pa (H) and (A) # 406-1 and (P) # 406-2; UNCo-Pa (P) #129; CHLMP (P) # 4927 (5 males and 8 females), and USNPC (P) # 102470. DS: Females attached to mucosa by caudal hook, males free or coiled around females (sometimes more than 1 for each female). Reference: Brugni & Viozzi (2010).
Host Galaxias platei Steindachner
SI: Stomach. Lo: Lakes: Moreno (41°03′S, 71°31′W), Cisne (42°36′S, 71°56′W) and Coyte (45°15′S, 71°12′W), Patagonia. MD: Not indicated. DS: Not indicated. Reference: Brugni & Viozzi (2010).
Host Oncorhynchus mykiss (Walbaum)
SI: Stomach. Lo: Moreno Lake (41°05′S, 71°30′W), Nahuel Huapi Lake (41°05′S, 71°20′W), Limay River; Musters Lake (45°33′S, 69°15′W) Senguer River, Río Negro-Chubut Provinces. MD: MACN–Pa 656/1. DS: gravid adults. Reference: Rauque et al. (2018).
Host Salmo trutta Linnaeus
SI: Stomach. Lo: Nahuel Huapi (41°05′S, 71°20′W), Limay River, Río Negro Provinces. MD: MACN–Pa 656/1. DS: gravid adults. Reference: Rauque et al. (2018).
Host Salvelinus fontinalis (Mitchill)
SI: Stomach. Lo: Moreno Lake (41°05′S, 71°30′W), Nahuel Huapi Lake (41°05′S, 71°20′W), Limay River; Cholila Lake (42°27.5′S, 71°40′W), Futaleufú River, Río Negro-Chubut Provinces. MD: MACN–Pa 656/1. DS: gravid adults. Reference: Rauque et al. (2018). Remarks: Adult nematodes of H. suttonae were originally described from G. maculatus and G. platei from Patagonia (Brugni & Viozzi, 2010; Rauque et al., 2018). Brugni & Viozzi (2010) reported that the intermediate host of this parasite is the amphipod Hyalella patagonica. Thus, its presence in salmonids probably represent a case of spillback (Rauque et al., 2018).
Superfamily Thelazioidea
Family Rhabdochonidae
Genus Rhabdochona Railliet, 1916
Synonyms: Ichthyospirura Skrjabin, 1917; Pseudorhabdochona Liu & Wu, 1941; Filochona Saidov, 1953; Rhabdochonoides Janiszewska, 1955; Afrochona Puylaert, 1973.
Rhabdochona sp.
Host Galaxias platei Steindachner
SI: Stomach. Lo: Zeta Lagoon (42°53′S, 71°20′W), Santa Cruz River, Chubut Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994).
Host Odontesthes hatcheri (syn. Patagonina hatcheri) SI: Intestine. Lo: Rosario Lake, Chubut Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994).
Host Oncorhynchus mykiss (Walbaum)
SI: Gastrointestinal tract. Lo: Zeta Lagoon (42°53′S, 71°20′W), Santa Cruz River, Chubut Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994). Remarks: The records of Rhadochona sp. in G. platei, O. hatcheri and O. mykiss could correspond to Rhadochona acuminata (Molin, 1860), since this parasite has been cited in many freshwater fishes from Patagonia.
Rhabdochona acuminata (Molin, 1860)
Synynonyms: Spiroptera acuminata Molin, 1860; Rhabdochona elegans Travassos, Artigas & Pereira, 1928; R. fasciata Kloss, 1966; R. australis Kloss, 1966; R. siluriformis Kloss, 1966.
Host Astyanax lacustris (Luetken)
SI: Intestine. Lo: El Tunal Dam (25°15′S, 64°25′W) Salta Province. MD: Not indicated. Reference: Cancino & Ramallo (2008).
Host Olivaichthys mesembrinus (Ringuelet) (syn. Diplomystes mesembrinus). SI: Intestine. Lo: Río Chubut, Chubut Province (43°39′-43°53′S, 66°22′-68°24′W). MD: MACN-Pa #37. DS: adults and third and fourth stage larvae. Reference: Cremonte et al. (2002).
Host Galaxias maculatus (Jenyns)
SI: Intestine. Lo: Nahuel Huapi Lake, Río Negro Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994). SI: Intestine. Lo: Río Chubut (43°39′-43°53′S, 66°22′-68°24′W) Chubut Province. MD: Not indicated. DS: Adults and third- and fourth-stage larvae. Reference: Cremonte et al. (2002).
Host Galaxias platei Steindachner
SI: Intestine. Lo: Ezquerra lagoon (41°03′S, 71°33′W) Santa Cruz Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994).
Host Hatcheria macraei (Girard) (syn. Thrichomycterus macraei).
SI: Intestine. Lo: Castaño River, San Juan Province. MD: CH-N-FML #07798. DS: Adults. Reference: Ramallo & Cancino (2021).
Host Lebias multidentata (Jenyns) (syn. Jenynsia multidentata)
SI: Intestine. Lo: Medina River (26°83′S, 65°80′W) Tucumán Province. MD: CH-N-FML#07418, #07419. DS: Adults. Reference: Ramallo (2005b).
Host Jenynsia alternimaculata (Fowler) **
SI: Intestine. Lo: Isasmendi Stream (24°48′S, 64°26′W), Salta Province. MD: CH-N-FML # 7511. DS: Adults. Reference: Ailán-Choke et al. (2014). SI: Intestine. Lo: La Caldera River (24°35′S, 65°22′W) Salta Province. MD: UNSa-IEBI-I N°0053. DS: Adults. Reference: Present study. Remarks: New locality record.
Host Odontesthes hatcheri (Eigenmann) (syn. Patagonina hatcheri)
SI: Intestine. Lo: Alicurá Reservoir, Pellegrini Lake, Neuquén Province. MD: Not indicated. DS: Adults. Reference: Ortubay et al. (1994).
Host Oncorhynchus mykiss (Walbaum)
SI: intestine. Lo: Lezama Lake and Alicurá Reservoir, Neuquén Province. MD: Not indicated. DS: Adults and third- and fourth-stage larvae. Reference: Ortubay et al. (1994).
Host Percichthys trucha (Valenciennes)
SI: Intestine. Lo: Limay River, Río Negro-Neuquén Provinces. MD: Not indicated. DS: Adults. Reference: Szidat (1956).
Host Trichomycterus spegazzinii (Berg) ***
SI: Intestine. Lo: La Caldera River (24°35′S, 65°22′W) and Yacones River (24°40′S, 65°24′W), Salta Province. MD: CH-N-FML 07790. DS: Adults. Reference: Present study. Remarks: New host and locality records. Records: Rhabdochona acuminata has been recorded in many freshwater fishes from Patagonia and Northwest Argentina (Ortubay et al., 1994; Cremonte et al., 2002; Ramallo, 2005b; Cancino & Ramallo, 2008; Viozii et al., 2009; Ailán-Choke et al., 2014). Taking into account these records, this parasite is considered a widespread species, encompassing almost all of South America (Cremonte et al., 2002).
Rhabdochona fabianae Ramallo, 2005
Host Bryconamericus iheringi (Boulenger)
SI: Intestine. Lo: Medina River (26°83′S, 65°80′W), Tucumán Province. MD: (H) CH-N-FML # 07422; (A) CH-N-FML # 07423; (P) CH-N-FML # 07424. DS: Adults. Reference: Ramallo (2005b).
DISCUSSION
Parasites have been recognized as key components of the biodiversity of an ecosystem, regulating the abundance or density of host populations, stabilizing food webs, and structuring host communities (Luque, 2008; Luque et al., 2016). Despite these key roles, they remain an underestimated component of the total biodiversity in many regions of the planet (Luque et al., 2016). Thus, studies identifying hotspots of high parasite diversity, as well as areas of relatively low parasite diversity, are crucial for a complete understanding of the functioning of the biosphere (Luque & Poulin, 2007).
The present study constitutes the most complete list of nematode parasites of freshwater fish from Argentina, including a complete bibliographic search of research on the subject. However, our current knowledge of the diversity of the nematodes parasitizing freshwater fish in Argentina is far from complete, due to the lack of sampling in several hydrological basin, families, and species of freshwater fish. To date, most sampling have been done in Great River and Patagonian ichthyogeographic provinces, while fish in Andean Cuyan, Aymaran, and Pampean ichthyogeographic provinces (Cuyan and Pampean regions) have been scarcely studied. This study effort is probably associated to the development of this line of work in scientific research centers in these regions. To date, only a small fraction of freshwater fish families and species in Argentina have been examined (21 out of its 56 fish families and 65 out of its 570 fish species) for the presence records of nematode parasites (Mirande & Koerber, 2020). The highest number of nematode parasites reported in Siluriformes and Characiformes probably reflects sampling effort, since these fish orders have the highest number of species in Argentina (Mirande & Koerber, 2020). Moreover, many species belonging to the above-mentioned fish orders are commercialized, which makes them available for parasitologists. On the other hand, the high number of nematode species recorded on Galaxiiformes could be related with its abundance and widely distribution across Patagonia (Barriga et al., 2002; Baigun & Ferriz, 2003), which makes them available for parasitological surveys in this region (Brugni & Viozzi, 2008; Viozzi & Semenas, 2009; Viozzi et al., 2009; Fernandez et al., 2012, 2015). However, several fish taxa are poorly studied, such as Rivulidae, Poecillidae, Anablepidae (Cyprinodontiformes), and Cichlidae (Cichliformes) that also present a high richness species with respect to other fish orders recorded in Argentina (Mirande & Koerber, 2020). In addition, some endemic fish species, such as Silvinichthys mendozensis Arratia et al., Trichomycterus heterodontus Eigenmann, T. belensis Fernández & Vari, Xyliphius barbatus Alonso de Arámburu & Arámburu (Siluriformes), Rhamphichthys hahni (Meinken, 1937) (Gymnotiformes) (López et al., 2008), have not yet been examined for nematode parasites. Therefore, we recommend prioritizing the examination of previously mentioned fish species in further studies, which will allow elucidating the real pattern of distribution and host spectra of the nematode parasites of freshwater fish from Argentina.
Camallanidae harbored the highest number of nematode species recorded in freshwater fish from Argentina, with S. hilarii, S. inopinatus and C. corderoi as the most common adult nematodes recorded. These species present a wide range of phylogenetically distantly related hosts belonging to different families of Characiformes and Siluriformes (in case of S. hilarii and S. inopinatus) and Atheriniformes, Galaxiiformes, Cyprinodontiformes, Centrarchiformes and Salmoniformes (in case of C. corderoi) (see Table 1). This fact could explain why these species are the most common, namely they are generalist species (see Moravec et al., 1993, 1997c; Ramallo, 1997, 2005a; Gallas et al., 2015; Rauque et al., 2018; Ailán-Choke et al., 2020). On the other hand, helminth larvae exhibit a low host specificity in fish, which increases their chances of reaching the definitive host, which could explain the wide host range presented by Contracaecum sp. larvae (Esch et al., 1988). Rauque et al. (2018) also reported that Contracaecum sp. was also the most generalistic parasite, however due to the large size of salmonids, it is not likely that piscivorous birds consume adult fishes, so these fish hosts could represent a dead end for this parasite.
This checklist may contain errors derived from the inclusion of misidentified host species, such as Astyanax bimaculatus, Leporinus maculatus, Serrasalmus spilopleura, and Zungaro zungaro, since they are not distributed in Argentina according to Mirande & Koerber (2020). These last three host records were cited by Hamann (1984, 1986, 1995/1996, 1999), but the examined fishes were not deposited in a collection. Thus, these fish records are doubtful and it is difficult to assess its taxonomic identification. In the particular case of A. bimaculatus, it was cited by Cancino & Ramallo (2008), but according to Lucena & Soares (2016) the material identified as A. bimaculatus corresponds to A. lacustris. Problems in the identification and taxonomy of host may affect the reliability of any parasitological studies and has implications for the assessment of host specificity, the elucidation of relationship between parasite and host phylogenies and the establishment of trophic links illustrated by life-cycle studies (Naylor et al., 2012; Alves et al., 2017). Therefore, it is recommendable that parasitologists deposit examined host in a reference collection and preserve a piece of host tissue in molecular-grade ethanol for sequencing and to work in synergy with fish taxonomists to be as accurate as possible in the fish identification (Alves et al., 2017). Other of obstacles that contribute to the lack of taxonomic accuracy in this checklist is the controversy about the validity of some nematode species that were previously listed. For instance, larvae of Contracaecum rudolphi, Camallanus tridentatus, and Goezia sp. are doubtful record of parasite and have to be carefully reviewed, since the examined material of these nematodes was not deposited in reference collections (Zeiss & Seigneur, 1981; Úbeda et al., 1989; Gilbert et al., 1993; Ortubay et al., 1994). It is important to highlight the need to clarify their taxonomic status by the examination of new material from type host and localities. Thus, our recommendation is the deposition of vouchers of the studied material in reference collections, and in the case of molecular studies the deposition of morphological voucher of molecular samples (i. e. piece of the organism used for the generation of molecular data, preserved in a way that can be used for morphological identification) (Blasco-Costa et al., 2016).
Among the nematode taxa reported in Argentinian freshwater fishes, five were identified only to genus level. Most of them correspond to larval stages, such as Eustrongylides sp., Contracaecum sp., and Hysterothylacium sp. The accurate specific identification of larval stages of nematodes is problematic, because they lack key features that are present in adults only (Moravec, 1998). In addition, there are few studies dealing with their genetic characterization (for example Sardella et al., 2020). Another reliable way to determine the species is to obtain adult nematodes from experimental infections of the definitive hosts (Moravec, 1998). However, studies on life cycles of these parasites are scarce in Argentina (Brugni & Viozzi, 2009). Therefore, integrative studies combining morphological and molecular data are necessary to improve the taxonomic resolution of the unidentified nematode larvae and to elucidate the real patterns of diversity of nematodes in Argentinian freshwater fish.
When comparing the number of parasitic nematode species of Argentinian freshwater fishes with that in other countries of South America, such as Paraguay (González-Solís & Mariaux, 2011) and Brazil (Luque et al., 2011; freshwater records only), it turns out that Argentina has a low number of species. We conclude that the biodiversity of freshwater fish hosts and their nematode parasites in the country is underestimated, due to: 1) a small fraction of the potential freshwater fish host in Argentina have been examined for nematode parasites, 2) the sampling bias in certain geographic regions and host species that may not reflect the real distribution patterns of these parasites, and 3) the lack of accuracy in taxonomic identification of some nematode species and its host species. To fill this knowledge gap, it is necessary to perform further investigation on this group of parasites, expanding the number of fish species examined, especially in poorly studied geographical localities.
ACKNOWLEDGEMENTS
We sincerely thank the anonymous reviewers for providing valuable comments and suggestions that contribute to improve the manuscript. The authors are thankful to Fabiana Cancino for her help in the field trip and fish identification. The present study was funded by Fundación Miguel Lillo (FML), Tucumán, Argentina. L. A. C. was supported by a Postdoctoral fellowship from the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET, Argentina).
