Herein we describe a new species of toad (genus Incilius) from Cerro Bollo in western Panama. The new species is unusual among toads in being earless, having sexual dichromatism, hands and feet with webbed digits that lack tubercles, and hypertrophied testes. The type locality of the new species is separated from the type locality of its congener, I. peripatetes, by ∼100 kilometers.

The cyprinid genus, Oxygaster van Hasselt, 1823, is the name-bearing type genus of the family-group name Oxygastri Bleeker, 1860, which predates many of the commonly used family-group names for the family Cyprinidae. Historically, the phylogenetic position of Oxygaster within the cyprinid phylogeny has been poorly understood, resulting in an uncertain status for its associated family-group name. The phylogenetic placement of Oxygaster and the status of the family-group name Oxygastri are examined herein using sequence data from four loci: two mitochondrial (cytochrome b, cytochrome c oxidase I) and two nuclear (opsin, recombination activating gene 1). A combined data matrix of 4117 bp for 109 taxa was collected and analyzed. Our results recovered Oxygaster within a large and taxonomically disorganized clade, one that has been reported in other studies on the Cyprinidae. The position of Oxygaster has wide-ranging consequences which led us to synonymize a number of cyprinid subfamilies and reorganize the current cyprinid classification. We recognize a monophyletic Oxygastrinae Bleeker, 1860 that includes the following genera: Aphyocypris, Candidia, Ctenopharyngodon, Culter, Hemigrammocypris, Hypophthalmichthys, Ischikauia, Macrochirichthys, Megalobrama, Metzia, Nicholsicypris, Nipponocypris, Ochetobius, Opsariichthys, Oxygaster, Parachela, Paralaubuca, Pararasbora, Parazacco, Squaliobarbus, Xenocyprioides, Xenocypris, Yaoshanicus, and Zacco. We place the following family-group names into the synonymy of Oxygastrinae Bleeker, 1860: Cultrinae Kryzhanovsky, 1947; Hypophthalmichthyinae Günther, 1868; Opsariichthyinae Rendahl, 1928; Squaliobarbinae Howes, 1981; and Xenocypridinae Günther, 1868.

Amioides, proposed as a synonym of Synagrops about 72 years ago, was recently recognized as a valid genus and provisionally placed in the Acropomatidae. Amioides is moved from Acropomatidae to Apogonidae based on family synapomorphies of having one supernumerary anal spine and a simple swimbladder. The first two anal spines have non-homologous positions in these two families based on the number of serial and supernumerary anal spines. Amioides is the senior synonym of Coranthus, a widely distributed, rarely collected, deep-dwelling cardinalfish (77–276 meters). A single species is recognized with Amioides grossidens as a junior synonym of Coranthus polyacanthus. Pore and free neuromast patterns for Amioides polyacanthus, new combination, are described.

Hemigrammocharax rubensteini is described from the northwestern Congo River basin in the Lékoli River of the Likouala River system, Republic of the Congo. The species differs from congeners in the combination of pigmentation pattern, meristics, and position of the dorsal fin. The presence of a well-developed pseudotympanum, a feature not previously reported in the Distichodontidae, is reported for H. rubensteini and other members of Hemigrammocharax and Nannocharax.

The bony-tongue fish genus Arapaima Müller has been considered monotypic since 1868, with A. gigas being the only recognized species. Review of species-level taxonomy of Arapaima has revealed that Arapaima agassizii Valenciennes (in Cuvier and Valenciennes, 1847) should be considered a valid species. The holotype was destroyed in World War II, but the species can be recognized based on the original description, which included detailed osteological illustrations. At least nine characters distinguish it from all other Arapaima: 1) dentary teeth 44 (counted on one ramus only, vs. 21–37 in other Arapaima); 2) maxillary teeth 43 (vs. 21–38 in other Arapaima); 3) orbit diameter 1.5% standard length (SL, vs. 1.5–2.8, relatively larger in all other Arapaima at similar SL); 4) interorbital width 4.1% SL (vs. 5.3–6.5 in other Arapaima); 5) parietals with pronounced posterior projections that are pointed and curve slightly toward midline (vs. absent in other Arapaima); 6) caudal fin widely separated from dorsal and anal fins by long caudal peduncle, 9.7% SL (vs. much shorter peduncle, 3.2–5.5 in others); 7) anal fin with only 26 rays (vs. 30–40 in others), with distinctly shorter basal length than dorsal-fin base; 8) dorsal and anal fins extremely low in profile; dorsal-fin base divided by longest dorsal ray about 7 (vs. 3.1–5.5 in others); and 9) first pectoral-fin ray with proximal tip similar in form to subsequent pectoral-fin rays (vs. first pectoral-fin ray noticeably enlarged relative to subsequent rays). Arapaima agassizii still is known only from the holotype, which was collected in 1817–20 somewhere in lowlands of the Brazilian Amazon. It thus is important to locate this taxon to determine its distribution and conservation status.

Characidium papachibe, new species, is described from the Rio Aruã, tributary of the Rio Tapajós basin, lower Amazon, State of Pará, Brazil. The new species can be easily distinguished from its congeners, except C. serrano and C. heirmostigmata, by the presence of anteriorly oblique, midlateral bands centered on lateral line or just ventral thereof and not reaching either the dorsum or the ventrum. Characidium papachibe is distinguished from C. serrano, C. heirmostigmata, and its psammophile congeners by the arrangement and number of the anteriorly oblique bars on the body sides, and by a simultaneous occurrence of morphometric and meristic characters. Comments about species groups are presented.

Characidium papachibe, espécie nova, é descrita do Rio Aruã, bacia do Rio Tapajós, baixo Amazonas, Estado do Pará, Brasil. A nova espécie pode ser facilmente distinguida dos congêneres, exceto C. serrano e C. heirmostigmata, pela presença de barras anteriormente oblíquas, centradas na linha lateral, não atingindo as regiões ventral ou dorsal. Characidium papachibe é distinguido de C. serrano, C. heirmostigmata e dos congêneres psamófilos pelo arranjo das barras oblíquas nas laterais do corpo e por uma ocorrência simultânea de caracteres morfométricos e merísticos. Comentários a respeito de grupos de espécies são apresentados.

Following perturbations like commercial harvests, turtles are susceptible to population declines because of life history characteristics such as long generation times, low recruitment rates, delayed maturity, and slow growth rates. Prior to gaining state-wide protection in 1993, the Alligator Snapping Turtle (Macrochelys temminckii) was commercially harvested in Arkansas. We conducted a mark–recapture study from 2005–2007 on a population of M. temminckii known to have been harvested in the East Fork Cadron Creek, a slow-moving stream in central Arkansas and part of the Mississippi River drainage. Captured turtles were marked, measured, weighed, and sexed. We compared observed characteristics to what would be expected if this population did not exhibit any evidence of past commercial harvest. We caught few large adults and approximately one adult for every juvenile. The adult sex ratio was highly female biased (6 F∶1 M). Population density (18 turtles/km stream reach) was slightly lower than expected. The apparent survivorship for males (0.96), females (0.88), and juveniles (0.80) appear to be as expected for a large freshwater turtle. Whereas high survivorship rates may ameliorate the effects of historical commercial harvest, slow growth rates, low reproductive success, and long generation times have assured these effects to be long lasting and still present within our study population. We also suggest that there are factors impeding recovery of this population, such as life history characteristics and incidental catch by fisherman.

Armenian vipers (Montivipera raddei) have a restricted and fragmented distribution throughout portions of Armenia, eastern Turkey, and northwestern Iran. Over the past 40 years their population numbers have dropped by nearly 88% due to a combination of over-collection for the pet trade, conversion of habitat to agriculture, and overgrazing by livestock. While a few studies have examined aspects of their reproductive biology, we know very little about the spatial ecology of this species. We used radiotelemetry to study the spatial ecology and habitat use of Armenian vipers inhabiting a landscape modified by human use in Kotayk Province, Armenia during the spring 2007–2009 (17 males, 11 females) and for complete active seasons 2008–2009 (8 males, 6 females). We found no significant difference between sexes for home range size, average movements, or movement rates through areas involving cropland versus strictly steppe. Home ranges were significantly larger for males whose spring core area included some cropland. Both sexes showed significant preference for mountain steppe over cropland. Despite these differences, the interspersing of cropland among steppe habitat does not appear to impede the snakes' movements and seasonal use of the available habitat. While conservation of intact mountain steppe habitat is the ultimate goal, providing corridors of habitat in areas of agricultural development should be considered a high priority for managing this viper population into the future.

Variation in mtDNA (cytb sequences) and six microsatellite loci was used to assess the conservation genetics and taxonomy of a group of populations of Gambusia in tributaries of the Rio Grande in Texas (USA) and Coahuila (Mexico): G. clarkhubbsi in San Felipe Creek, Texas, and G. krumholzi. The latter has been considered endemic to the Río de Nava of the Río La Compuerta system, Coahuila, but we found it more widely distributed, both in the Río La Compuerta and outside that system, with a population in the Río San Diego, another Rio Grande in Coahuila. Our results, including reassessment of the morphological characters used to describe G. clarkhubbsi, suggest that G. clarkhubbsi is a junior synonym of G. krumholzi. The San Felipe Creek population (G. cf. clarkhubbsi) had only the common cytb haplotype of G. krumholzi, and none of the microsatellite loci was diagnostic of the two. However, the San Felipe Creek population is the most divergent of the known populations of G. krumholzi. Diversity attributable to among-population differences was six-fold greater when the San Felipe Creek population was included in the AMOVA than when it was excluded (38.5% versus 6.5%). A search for evidence of genetic introgression by G. speciosa as a factor in microsatellite divergence found only one F₁ hybrid and two first-generation backcross progeny. Based on the genetic structure and restricted distribution of G. krumholzi, the San Felipe Creek population and four populations in Mexico are recommended as management units for future monitoring.

La variación en el ADNmt (secuencias cytb) y en seis loci microsatélites se utilizó para evaluar la genética de conservación y la taxonomía de un grupo de poblaciones de Gambusia en tributarios del Río Bravo en Texas (EEUU) y Coahuila (México): G. clarkhubbsi de San Felipe Creek, Texas, y G. krumholzi. Esta última ha sido considerada endémica del Río de Nava del sistema del Río La Compuerta, Coahuila, pero la encontramos más ampliamente distribuida, tanto en el río La Compuerta y fuera de ese sistema, con una población en el río San Diego, otro tributario del Río Bravo en Coahuila. Nuestros resultados, incluyendo la reevaluación de las características morfológicas utilizadas para describir G. clarkhubbsi, sugieren que G. clarkhubbsi es un sinónimo menor de G. krumholzi. La población de San Felipe Creek (Gambusia cf. clarkhubbsi) tuvo sólo el haplotipo cytb más frecuente de G. krumholzi, y ninguno de los loci microsatélites fue diagnóstico de los dos. Sin embargo, la población de San Felipe Creek es la más divergente de las poblaciones conocidas de G. krumholzi. La diversidad atribuible a las diferencias entre poblaciones fue seis veces mayor cuando la población de San Felipe Creek se incluyó en el AMOVA que cuando fue excluida (38.5% versus 6.5%). Una búsqueda de evidencia de introgresión genética por G. speciosa como factor de divergencia microsatélite encontró sólo un híbrido F₁ y dos progenies de la primera generación de retrocruzamiento. Debido a la estructura genética y la distribución restringida de G. krumholzi, se recomienda que la población de San Felipe Creek y cuatro poblaciones de México se mantengan como unidades de manejo para monitoreo futuro.

The Mayan Cichlid (Cichlasoma urophthalmus) is an omnivorous fish endemic to Central America that was first recorded in South Florida in 1983. We examined their effects on native fishes in estuarine mangrove habitats between 1991 and 2006. Four major cold fronts passed during the study period and each killed many Mayan Cichlids, providing multiple opportunities to observe native fish responses to fluctuation in cichlid densities. Fish assemblage data were collected using drop traps placed at three estuarine sites and one impounded site. Analysis of similarity indicated that differences in assemblage structure among the four sites correlated with the presence of Mayan Cichlids. At two sites with high Mayan Cichlid density, SIMPER analysis revealed that relative densities of Sheepshead Minnows (Cyprinodon variegatus), killifish species, Clown Gobies (Microgobius gulosus), Eastern Mosquitofish (Gambusia holbrooki), Sailfin Molly (Poecilia latipinna), Tidewater Silverside (Menidia peninsulae), and species of Lepomis were correlated with Mayan Cichlid relative density. Time series analysis of data from the two sites with high Mayan Cichlid density indicated negative relationships between their density and density of Sheepshead Minnow, Marsh Killifish (Fundulus confluentus), and Eastern Mosquitofish after controlling for salinity. When present, the per capita impacts on Sheepshead Minnows were 40% to 60% greater than on the other taxa. Partial regression slopes of native fish density on Mayan Cichlid density were negative with unpatterned residuals across a broad range of cichlid densities, providing no indication of predator saturation or interference at high density. This may have resulted because of immigration of native fish to these sites during the South Florida dry season.

With the current rate of declines in global biodiversity, it is apparent that wildlife diseases are serving as additional threats to population declines and potentially species extinctions. Free-ranging Eastern Massasaugas (Sistrurus catenatus catenatus) have been reported susceptible to numerous health threats, one of which is a fatal fungal dermatitis. In response to the occurrence of the fungal dermatitis, a health survey and disease investigation was conducted on Eastern Massasaugas near Carlyle, Illinois in 2011. We captured 38 Eastern Massasaugas from March to April 2011. Polymerase chain reaction assays were performed from swabs collected from the faces of 34 snakes. We obtained hematologic data for 31 individuals, plasma biochemical data for 24, and toxicological data for 18. There was no evidence of Chrysosporium in any of the samples. Hematologic and plasma biochemistry parameters were consistent with previous health studies in the Carlyle population. Elemental toxicologic investigation of the plasma indicated variable levels of lead, copper, selenium, strontium, tin, iron, and zinc.

The ecological links of aquatic invasive fish and native reptiles are rarely studied. Thus, we analyzed the diet and helminth composition of a recently introduced invasive alien fish (the Rotan, Perccottus glenii) and of two native semi-aquatic snakes (the Dice Snake Natrix tessellata, the Grass Snake N. natrix) in Cranberry Lake, Russia. We also studied diet and helminthes of water frogs (Pelophylax spp.) as a potential mechanism of transmission of parasites. We identified 19 prey taxa and four helminthes for P. glenii, 21 and 24 for Pelophylax spp., and two and 16 for the snakes. The piscivorous N. tessellata has been feeding on P. glenii since its introduction and the subsequent elimination of native fish. Although we did not find P. glenii in the diet of the mainly frog-eating N. natrix, helminth analysis indicated that this snake may prey upon this fish. Both studied snakes contracted the parasitic tapeworm Ophiotaenia europaea from P. glenii. Therefore, the invasive fish and the native snakes demonstrate direct (consumption of fish by snakes) and indirect (transmitting of parasite species) interspecies interactions, which link aquatic and terrestrial habitats. Thus, the invasive fish P. glenii replaced the eliminated native fish in the food web of this lake inhabited by semi-aquatic snakes and became part of the parasite system that includes the native snakes. This is the first evidence of indirect interactions between P. glenii and native reptiles.

We quantified illegal and unmonitored harvest of three endangered sideneck turtles (Podocnemis spp.) by examining discarded turtle shells in 29 riverine communities both up- and down-river from the Arrau Turtle Wildlife Refuge in the Middle Orinoco, Venezuela. We compared harvested turtle sizes to those captured during in-water research surveys to determine harvest selectivity. We found fresh sideneck turtle shells in most communities visited; carapaces and plastrons from P. expansa were the most abundant despite their protected status. Turtle harvest was skewed toward females in all species, and toward juvenile P. expansa and adult P. unifilis and P. vogli. Considering historical accounts of widespread turtle husbandry in the area, Podocnemis spp. life history, and population recovery for these species in community-based conservation programs elsewhere in South America, we recommend community-managed captive breeding of faster-maturing P. unifilis and P. vogli to satisfy turtle consumption needs. These measures, along with improved nesting-beach protection, may allow recovery of populations of P. expansa and make possible their legal subsistence harvest in the future.

Adult Black Redhorse (Moxostoma duquesnei) were seined from the Grand River, Ontario and artificially spawned in May 2007 and May 2008. Eggs hatched after 9–16 days at a mean temperature of 20°C, and after 11–25 days at a mean temperature of 17°C. Eggs did not develop fully at temperatures <11°C. Eggs and development of larvae between 9 and 24 mm TL, and juveniles up to 35 mm TL are described. Ontogeny of larval and juvenile Black Redhorse was compared to that of Greater Redhorse (Moxostoma valenciennesi), River Redhorse (Moxostoma carinatum), Golden Redhorse (Moxostoma erythrurum), Shorthead Redhorse (Moxostoma macrolepidotum), Copper Redhorse (Moxostoma hubbsi), and Spotted Sucker (Minytrema melanops). There was significant overlap between most meristic variables compared. However, the majority of Black Redhorse in this study (up to 18 mm TL) generally had higher myomere counts that were different from most other redhorse species. These data, in combination with knowledge of variation in congeneric distributions and differences in spawning windows, may allow identification of Black Redhorse as small as 9 mm TL.

Although cartilage and bone are often stained to study development in fishes, collagen forms before either of these tissues during skeletal ontogeny. We describe a new method that combines conventional trypsin clearing of whole-mount specimens with staining of Collagen Type II using antibodies. Specimens were fixed briefly in paraformaldehyde, digested in a trypsin solution, bleached with hydrogen peroxide, permeabilized with Proteinase K, antigen labeled with primary and secondary antibodies, and stored in glycerol. This method makes both cellular and acellular collagen visible under ultraviolet light with limited background staining. Specimens showed no signs of damage from any of the solutions used for staining, but the length of time for fixation appears to be important. This method permits visualization of collagen condensation prior to cartilage formation in endochondral bone and can be used to study evolution of skeletal ontogeny and to develop new skeletal characters for phylogenetic analysis.

The micro and macro structures of the caudal vertebrae and muscles of Dendrophidion dendrophis and Mastigodryas bifossatus were described using histological slides, dissections, radiographs, and clearing and double staining of intact, broken, and healed tails. To analyze the relationship among the frequencies of healed tails we established two populations of D. dendrophis and six groups of M. bifossatus. We found that fractures of the tail in the two species are intervertebral, and there are no morphological and/or structural mechanisms that facilitate the urotomy, which is classified as non-specialized pseudoautotomy. The caudal vertebrae of D. dendrophis and M. bifossatus show minor differences in the shape of the condyle, cotyle, and border of the neural spine, and in the size and orientation of the hemapophysis and pleurapophysis. The absence of bleeding at the moment of tail breakage may indicate the presence of sphincters in the veins and arteries of D. dendrophis. The distal part of the last vertebrae retained in healed tails of D. dendrophis and M. bifossatus participates in the healing processes as a possible source of calcium in the formation of a calcified cap. We found high frequency of tail breakage in both species, which occurs in almost the entire length of the tail, with no specific areas of concentration. There was no difference in the frequencies of healed tails among males and females of different populations of D. dendrophis and M. bifossatus. Juveniles have lower breakage frequencies than adults in both species, except for populations of M. bifossatus from the Cerrado and Pampa.

Species inhabiting running waters have evolved life-history strategies and morphological characteristics that allow them to survive in fluctuating river environments. Riverine turtles often have behavioral responses associated with seasonal drying and flooding, and morphological variation that is correlated with physical instream habitat. We compared movement behavior, body size, and body condition of Western Pond Turtles (Actinemys marmorata) under two different flow regimes: a regulated reach with dam-influenced perennial flow and a naturally intermittent reach upstream of the dam. We used radiotelemetry to track the seasonal movements of turtles at both sites and compared body size and condition through data gathered during snorkel surveys. We found that timing of migration was significantly influenced by flow regime. Turtles in the intermittent reach departed the river earlier than those in the perennial reach, and also migrated to the river earlier in the spring. Overall, turtles from the intermittent reach spent less time annually in the water, and adults were significantly smaller and had lower body condition compared to those from the perennial reach. In our study system, a dam converted part of a historically intermittent reach to a perennial one; this apparently had some positive effects, such as increased foraging time, larger body size, and better body condition. However, there may be tradeoffs with regard to habitat quality for rearing juvenile turtles to assure recruitment and persistence of the population.

Divergent visual signals and associated mate preferences are frequently hypothesized to result in behavioral isolation between species lineages. Females are traditionally predicted to be the choosier sex, using visual cues such as male color to facilitate mate recognition and assessment. However, a number of authors have hypothesized that males also are selective in choosing mates and that male preferences can be important in maintaining behavioral isolation. Darters of the genus Etheostoma (Percidae) are a diverse group of sexually dimorphic fishes in which males of most species exhibit elaborate nuptial coloration during spawning seasons. Male coloration is hypothesized to play a role in maintaining behavioral isolation between darter species, and females show association preferences for conspecific male coloration. However, the degree to which males exhibit preferences for conspecific female visual cues is less clear. We examined conspecific association preferences based only on visual signals in male Redband Darter, Etheostoma luteovinctum. We presented individuals with a choice of a conspecific female or a female E. hopkinsi, a heterospecific that is almost completely behaviorally isolated from E. luteovinctum and differs in coloration and body shape. Males exhibited a statistically significant association preference for conspecifics in dichotomous choice trials where only visual cues were available. This is the first study to document a significant conspecific association preference in males of a darter species, providing evidence that males may contribute to behavioral isolation from E. hopkinsi. Differences in female coloration, body shape, or behavior appear to serve as important signals that would help maintain behavioral isolation between E. luteovinctum and E. hopkinsi upon secondary contact.

Evidence is accumulating for the ability of animal embryos to hatch early in response to the immediate threat of egg predation. However, early hatching in response to predation is known from only amphibians, fish, and invertebrates. Herein we present the first quantitative evidence for induced early hatching in a reptile. In two laboratory experiments, delicate skink (Lampropholis delicata) embryos responded to a surrogate predator cue—vibrations—by hatching ∼3 days earlier than their spontaneously hatching clutchmates. Early hatching embryos were significantly smaller and left more residual yolk in their eggs, however, suggesting a cost to hatching early. Assuming our vibrations were interpreted as an increase in predation risk, skink embryos can thus forego some yolk absorption and growth when threatened by imminent predation. Simulated predation experiments in the field induced hatching in both nest sites (horizontal rock crevices) and in eggs displaced from nest sites. The hatching process was explosive: early hatching embryos hatched in seconds and sprinted from the egg an average of ∼40 cm as they hatched. Our results are unusual in demonstrating early hatching in a terrestrial animal with a simple life cycle, and likely extend predation-induced early hatching to reptiles. Early hatching may be widespread in oviparous vertebrates.