Xyliphius sofiae, new species, is described based on a unique specimen exhibiting four autapomorphies: eyes absent vs. present (though reduced); color pale, lacking pigment vs. head and body darkly pigmented; branchiostegal rays five vs. four; and unculiferous tubercles on posterior body distributed evenly vs. enlarged unculiferous tubercles typically arranged in five distinct rows above pelvic-fin base to posterior end of caudal peduncle. In addition, the pectoral fin of X. sofiae, new species, has one ossified proximal radial vs. two in congeners (except X. magdalenae, not examined). Xyliphius sofiae, new species, differs from all congeners except X. lepturus by snout tip elongated and narrowly rounded vs. short and broadly rounded, often with small median notch; fifth ceratobranchial relatively narrow with elongate acicular teeth vs. broadly expanded, leaf-shaped, with shorter and broader, conical teeth; anterior limits of branchial apertures separated by distance less than length of aperture vs. greater than length of aperture; anal-fin rays modally nine vs. seven; and lateral line extending onto base of caudal-fin rays vs. finishing in hypural region. Based on the single specimen collected in the main channel of the Río Amazonas near Iquitos, Peru, we describe the osteology of X. sofiae, new species, using a non-invasive technique: high-resolution X-ray computed tomography (HRXCT). We consider Xyliphius lombarderoi Risso and Risso, 1964, a species based on a unique holotype that is now lost, to be a subjective junior synonym of X. barbatus Alonso de Arámburu and Arámburu, 1962. Variable characteristics are summarized for the seven species of Xyliphius treated here as valid, and their distributions are plotted based on a comprehensive review of museum specimens.

Recent research has demonstrated that some freshwater turtles vocalize underwater, but the taxonomic breadth of this mode of communication in freshwater turtles is unknown, hindering our understanding of its evolution. The Pig-nosed Turtle ( Carettochelys insculpta) , a monotypic genus inhabiting tropical Australia and New Guinea, is a likely candidate for producing underwater sounds because it exhibits social behavior while feeding, nesting, and thermoregulating. We tested the hypothesis that C. insculpta vocalizes using an omnidirectional hydrophone. We recorded C. insculpta emitting sounds underwater in the field and in captivity in northern Australia in May 2014. Analysis revealed that the 182 sounds produced by seven individuals could be separated into three sound categories. The sounds were simple and characteristic of a contact call, and were similar to those recently reported in other species of aquatic turtles. Further research should focus on the role of sound production in social activities.

Stream drying and in-stream barriers can influence migration and recolonization, yet we know little about how these impact population genetics of fishes. We analyzed microsatellite DNA from two common headwater fishes, Longear Sunfish ( Lepomis megalotis ) and Highland Stoneroller (Campostoma spadiceum), to compare population genetics of fishes in streams with varying degrees of connectivity. We sampled perennial and intermittent streams including examples with and without anthropogenic structures (road crossings). An additional perennial stream with a large waterfall was added to examine potential effects of a natural structure. We collected between 24 and 30 individuals of each species from three equidistant locations along each of five study streams. We found that Longear Sunfish and Highland Stoneroller populations experienced greater reductions in gene flow along the intermittent streams than along the perennial streams. However, the greatest reduction in gene flow between sub-populations generally coincided with the presence of permanent in-stream structures. Our study highlighted how overall genetic connectivity of fish populations is reduced by stream drying and showed that these effects can be exacerbated by in-stream barriers.

High levels of salinity often have lethal and sublethal effects on amphibians. In Mexico, salinization is threatening some rivers in arid and semi-arid regions. Here, we report the results of an experiment examining the effects of salinity and density on Pine Toad ( Incilius occidentalis ) tadpoles from the Río El Sabino in the Tecomavaca Canyon in Oaxaca, Mexico. Tadpoles of Incilius occidentalis from Oaxaca were not affected by salinities up to 0.8 ppt in either survivorship or total length. Our results for survivorship and total length are consistent with results from another population of I. occidentalis from the Río Salado in Puebla, Mexico. We found that density reduced total length (i.e., growth) but not survivorship, whereas similar densities did not affect survivorship or size at metamorphosis in the tadpoles from the Río Salado. These results suggest the potential for the existence of differences in the larval ecology of I. occidentalis from these two populations.

We describe the larval external morphology and internal oral features of Proceratophrys mantiqueira from its type locality and provide novel natural history information for adults. The tadpoles of P. mantiqueira (Stage 37) exhibit a depressed body with low tail fins, eyes positioned dorsally, and a ventral oral disc bordered by a single row of marginal papillae, with a wide gap on the anterior labium; a few submarginal papillae may be present. The labial tooth row formula is 2(2)/3(1). The shape and amount of papillae in the buccal floor, especially the infralabial and lingual papillae, can distinguish the tadpole of P. mantiqueira from other congeners. Our results add important new data about the larval morphology of this species and may help future studies on the intrageneric relationships of Proceratophrys.

Using a variety of techniques, we tracked dispersing juvenile and migrating adult Crawfish Frogs ( Lithobates areolatus ) to determine how these movements produce the relatively high degree of interconnectivity we previously found among breeding wetlands at Hillenbrand Fish and Wildlife Area-West (HFWA-W) in southwestern Indiana. We found that newly metamorphosed juveniles disperse in all directions, with average daily movements between 27 m (2015) and 35 m (2011) and maximum daily movements of 114 m (2011) and 297 m (2015). When placed in artificial burrows, juveniles tended to abandon them in order to continue dispersing. Of the 196 juveniles produced at Nate's Pond and subsequently captured as breeding adults, 141 (71.9%) returned to Nate's; the remainder dispersed to five other breeding wetlands, including one that was 1.35 km away. Adults were also vagile. At Nate's, only 137 (50.6%) of the 271 adults that bred there from 2012–2016 were produced there. Further, of the 255 Crawfish Frog adults breeding at least twice, 57 (22.4%) were captured at different wetlands. As a component of a comprehensive management plan that considers juvenile Crawfish Frogs, we suggest minimizing summertime aboveground disturbance through the use of mowers, all-terrain vehicles, trucks, and heavy equipment. Plowed areas such as food plots should be narrow and placed in a radial pattern in relation to breeding wetlands to preclude juveniles crossing tangentially oriented areas of bare ground, which expose them to predators.

Many factors influence community structure, including stochastic, historical, or ecological factors. We test how phylogenetic relationships and morphology influence patterns of diet and microhabitat niche partitioning of an anuran community in the Atlantic forest in northeastern Brazil. We conducted fieldwork in an urban fragment of the Atlantic forest. Niche breadth for microhabitat use was low for all species pairs, whereas diet niche breadth was high for most. The main prey categories were Coleoptera and Orthoptera, and closely related species showed a distinct diet. We also found a non-random pattern of resource use for diet and microhabitats. Phylogenetic relationships influenced microhabitat, but not diet, use of hylids and leptodactylids. Morphological variability was not clustered in only one node, nor in a few nodes, and trait values were not skewed to the root or the tips of the phylogeny and appear to concur with phylogenetic relationships for microhabitat use. Therefore, phylogenetic relationships influenced microhabitat use, whereas ecological processes determined diet.

Muitos fatores influenciam a estrutura de uma comunidade, sejam de ordem estocástica, histórica ou ecológica. Nós testamos como as relações filogenéticas e a morfologia influenciam os padrões na partição de nicho da dieta e uso de microhabitat em uma comunidade de anuros de Mata Altântica do nordeste do Brasil. Nós conduzimos o estudo em um fragmento urbano de floresta atlântica no nordeste brasileiro. A largura de nicho de uso de microhábitat foi baixa para todos os pares de espécies, enquanto a de dieta foi alta para a maioria. As principais categorias alimentares foram Coleoptera e Orthoptera, sendo que espécies mais próximas filogeneticamente apresentaram dieta distinta. Nós também encontramos um padrão não aleatório no uso dos recursos de dieta e uso de microhábitat. O grau de parentesco influenciou o uso de microhábitat em hilídeos e leptodactilídeos, mas não a dieta. A variabilidade morfológica não foi agrupada em um nó, nem em poucos nós, e os valores dos atributos não estão enviesados em direção a raiz ou aos ramos terminais da filogenia, e, aparentemente, corrobora as relações filogenéticas para uso de microhábitat. Portanto, o parentesco filogenético influenciou o uso de microhábitat, enquanto a dieta foi mais influenciada por processos ecológicos.

An increasing body of research shows the ability of parasites to alter the reproductive condition of their hosts, and the hosts' capacity to shift resources allocated to reproduction in response to parasitism. Here we compare host reproductive condition to gill parasite infection load in Fantail Darters ( Etheostoma flabellare ) of Mill Creek, Tennessee, USA, over the course of a year. We sought to determine whether host reproductive season or condition correlated with parasite load, whether parasite load differed between host sexes, and whether parasite load correlated with clutch size in females. We sampled the host population bimonthly and measured host physical and reproductive characteristics and gill parasite load. Infection levels significantly decreased when host reproductive activity ceased. Parasite load did not correlate strongly with body size in either sex. Male hosts were significantly more heavily infected than female hosts. No negative relationship was found between reproductive condition and parasite load in either sex. However, a significant positive correlation was observed between host clutch size and intensity of parasite infection in females, even when controlling for body size. The immunocompetence handicap hypothesis suggests that sex differences in parasite infection levels may be due to an immune defense cost incurred by males as a result of androgen-mediated reproductive effort. Females may have evolved a compensatory response to heavy parasite infection in which they shift androgen-mediated reproductive effort towards larger clutch sizes. Further study is needed to elucidate the relationship between host reproductive timing and seasonal patterns of parasite infection.

A new species of the deep-sea ceratioid anglerfish genus Oneirodes Lütken (Lophiiformes: Oneirodidae) is described on the basis of a single female specimen collected from the Western Indian Ocean. The new form is distinguished from its congeners by a combination of features that includes a relatively short illicium, a unique escal morphology, and shape of the subopercle bone.

A new species of Eigenmannia is described from the Río Pucuro, Río Tuíra basin, Panama. It is diagnosed from all congeners by the position of the mouth, the color pattern, the number of anal-fin rays, the number of scales on lateral line, the number of scales rows above the lateral line, the number and arrangement of teeth on the dentary, the number of precaudal vertebrae, the relative depth of the posterodorsal expansion on infraorbitals 1 2, and the relative size of coronomeckelian bone. The new species is the first Eigenmannia described from Central American drainages, and the northernmost species of the genus.

Una nueva especie de Eigenmannia es descrita del río Pucuro, que pertenece a la cuenca del Río Tuíra, Panamá. Esta diagnosticada de las demás especies del género por la posición de la boca, el padrón de coloración, el número de radios de la aleta anal, el número de escamas de la línea lateral, el número de hileras de escamas arriba de la línea lateral, el número y disposición de los dientes en el hueso dentario, el número de vertebras pre-caudales, el tamaño relativo de la expansión postero-dorsal del hueso infraorbital 1 2 y el tamaño relativo del hueso corono-meckeliano. Esta nueva especie es la primera Eigenmannia descrita de las cuencas de América Central y además es la especie con la distribución más boreal del género.

Estimates of abundance and density for the imperiled Clinch Dace (Chrosomus sp. cf. saylori) are needed across its range to indicate where populations exist and estimate their long-term viability. We generated estimates of population extent, measured in km of potentially occupied habitat, based on 206 site visits from four fish surveys since 1999 within the Clinch Dace's putative range. Next, we used mark–recapture surveys to estimate Clinch Dace densities in five occupied streams. A linear regression model generated from these data was used to transform single-pass count data into estimated abundance with 90% prediction intervals (PI) for Clinch Dace in sampled reaches. We combined estimates of individual population sizes to estimate global abundance. Finally, we examined the correlation between habitat variables and Clinch Dace abundance in occupied streams. Clinch Dace populations at low densities potentially occupy 31.5 km of the approximately 351 km of 2^nd- and 3^rd-order streams in northern Russell and Tazewell counties in Virginia. Individual population census sizes ranged from 11 to 1,675 individuals. Estimate of combined global census population size for ten of 16 populations was 6,706 (90% PI = 2,847–22,594) adults. Clinch Dace populations are small and isolated. Clinch Dace abundance exhibited weak negative correlation to indices of current and recent surface mining. Regular population monitoring and prompt conservation action are needed to protect Clinch Dace populations, including protecting forested land cover from clearing for logging and mining.

The Mobile Basin has undergone extensive channel modification with corresponding declines in the distribution and abundance of native aquatic fauna. However, many of the declining aquatic species of the Mobile Basin may persist within unmodified sub-basins. The Noxubee River is a sub-basin of the Mobile Basin that is relatively unaltered throughout its watershed, and we hypothesized that the system could serve as a refugium for declining riverine species of the Mobile Basin. We characterized species richness and assemblage structure of fishes in the Noxubee River and its tributaries to determine whether or not contemporary fish assemblages resembled the historical assemblages as described before construction of the Tennessee-Tombigbee Waterway. We found that fish assemblages of the contemporary river are similar to those of the historical river, and many species now absent from another portion of the Mobile Basin are still present and maintain similar distribution and abundance patterns. Our results are informative because there is little existing information available regarding fish assemblages in the Noxubee River since major alterations were imposed upon the Mobile Basin through construction of the waterway. These results are discussed relative to findings from another Mobile Basin tributary that exhibited a marked change in many fish assemblage properties following construction of the waterway. Variable resiliency among tributaries to altered main-channel rivers illustrates the need for predictive tools that can be employed to prioritize conservation efforts.

We quantified factors contributing to failed or successful prey captures by Pipa pipa, a permanently aquatic, tongueless frog widely distributed in Amazonian South America. Pipa catches fish by entraining and ingesting large volumes of water and by limiting fish escape with its fingers. Based on analysis of high-speed video (250 and 500 fps), feeding attempts appeared superficially stereotyped, but many features were modulated and slower than in other suction feeders. For both successful and unsuccessful capture attempts, the entire frog might or might not move and fingers might or might not contact the prey. Mouth opening generated initial suction but continued movement of entrained water depended on actively enlarging the volume of the anterior trunk by depressing the ventral pectoral girdle. Although captured fish varied in size and position relative to the frog, both fish size and the distance of the fish from the frog's mouth at the initiation of mouth opening were significantly greater for unsuccessful attempts. Our data suggest that capture success depends partly on sensory evaluation of prey size and distance that initiate capture movements and partly on the independent probabilities of rapidly moving parts in two different organisms favoring the predator or its prey.

Fine-scale habitat information can provide insight into species occupancy and persistence that is not apparent at the landscape-scale. Such information is particularly important for rare species that are experiencing population declines, such as the threatened Yosemite Toad (Anaxyrus canorus). Our study examined differences in physical characteristics of occupied and unoccupied toad breeding pools within meadows, and then used a logistic regression model to evaluate if occupancy was related to the physical microhabitat variables. We found that occupied pools on average were deeper by 0.7 cm, warmer by 3°C, and had 50% more surface water along the short axis of the pool. Mean water depth, mean water temperature, the amount of surface water in the pools, mean detritus depth, and mean vegetation height were significant predictors of toad occupancy. Despite variation in larger-scale environmental conditions such as yearly winter snow cover and precipitation, occupancy was not related to individual years and microhabitat requirements for toad occupancy appear to be relatively constant. Pools were very shallow water bodies (mean depth 4.35 cm for occupied pools), and differences in physical microhabitat variables for suitable breeding sites were small but significant. This underscores the importance of fine-scale habitat information for breeding and reproduction of A. canorus, and for species persistence and management.

Nettorhamphos radula, new genus and species, is described from two specimens, 20.3–40.2 mm SL, trawled from sponge and algae reefs between 30–40 meters in depth offshore from Fremantle, Western Australia. The new taxon is distinguished from all other members of the Gobiesocidae by having vast fields of tiny conical teeth throughout the oral jaws that are arranged in multiple, regular rows along the lingual surface of the premaxilla and the dentary. The new taxon is tentatively considered a close relative of two other southern Australian endemic clingfish taxa (Posidonichthys and the undescribed “Genus A”) based on the presence of a well-developed and heavily ossified subopercular bone that articulates strongly with both the opercle (dorsally) and the preopercle (anteriorly).