<i>Ichthyology & Herpetology</i> (formerly <i>Copeia</i>) publishes work on the biology of fishes, amphibians, and reptiles, or work using those organisms as models for testing hypotheses of broad significance.

Hybridization between populations along the path to complete reproductive isolation can provide snapshots of speciation in action. Here, we present a comprehensive list of salamander hybrids and estimate genetic distances between the parental hybridizing species using one mitochondrial and one nuclear gene (MT-CYB and RAG1). Salamanders are outliers among tetrapod vertebrates in having low metabolic rates and highly variable sex chromosomes. Both of these features might be expected to impact speciation; mismatches between the mitochondrial and nuclear genomes that encode the proteins for oxidative metabolism, as well as mismatches in heteromorphic sex chromosomes, can lead to reproductive isolation. We compared the genetic distances between hybridizing parental species across four main tetrapod groups that differ in metabolic rates and sex chromosome diversity: salamanders, lizards, mammals, and birds. Our results reveal no significant differences, suggesting that variation in these traits across vertebrates does not translate into predictable patterns of genetic divergence and incompatible loci in hybrids.

Resource partitioning in communities is often achieved by sympatric species having different morphologies that allow them to access different resources. This is because differences in morphology influence an organism's capability to perform a task that is relevant to their ecology. Here, we compare limb, shell, and head morphology, swimming performance, habitat use, and diet of three species (Rhinoclemmys rubida , R. pulcherrima, and Kinosternon chimalhuaca) that co-occur in the tropical dry forest of Chamela, Jalisco, Mexico. We found that these species do not overlap in both habitat or diet, and the overlap that we observed in habitat was contrasted by differences in diet. We also found a consistent relationship among limb and shell morphology, swimming speed, and habitat. Rhinoclemmys rubida occupies the driest deciduous forest atop and along hills, has shorter hands, less interdigital webbing, longer plastrons, more-domed shells, and slower swimming speeds in proportion to body size. In contrast, Kinosternon chimalhuaca exclusively occupies arroyos or seasonal streams, has longer hands, more interdigital webbing, smaller plastrons, less-domed shells, and faster swimming speeds in proportion to its body size. Rhinoclemmys pulcherrima was found in all habitats and intermediate in morphology and swimming speed between the other two species. Therefore, in this study system, limb and shell morphology are good indicators of habitat differences between turtle species. These differences are likely due to the influence that limb and shell morphology have on swimming performance. Relationships between head morphology and diet were less clear, which might be the result of changes in behavior or habitat rather than morphology. Patterns of resource partitioning in Chamela seem to coincide with other studies of turtle communities, which suggests that relationships among morphology, performance, and ecology that we observe here might be a general pattern across turtles.

Homing is a behavior in which an animal returns to a specific place after they have moved or migrated to a distant place. In anurans, most of our knowledge about homing comes from studies in temperate-region species with nocturnal activity and reproduction associated with ponds. Recently, studies with poison frogs (Dendrobatidae) have increased our understanding about homing in tropical frogs with diurnal activity, and that do not breed in large ponds. The Rubí Poison Frog Andinobates bombetes offers a good opportunity to further increase the knowledge of behavioral ecology of homing in anurans because some natural history traits in this species differ from those exhibited in most poison frogs in which homing ability has been studied. For instance, A. bombetes have a smaller body size and use phytotelmata in bromeliads for tadpole development while others use terrestrial pools. To quantify the homing ability and the factors influencing it in A. bombetes, we performed translocation experiments of individuals at distances between 5 and 90 m outside their territory in a forest remnant located in the department of Quindío, Central Andes of Colombia. In this study, we included a large sample size of females, which is important because homing studies with poison frogs has been almost exclusively studied in territorial males. Of 104 displaced individuals, 39 returned to their territory. The probability of homing in A. bombetes was negatively related to the translocation distance, but was unrelated to body size and sex. Apparently, this species has a limited homing ability when compared to most poison frogs studied so far except for O. pumilio, which seems more similar in body size and resources used for reproduction. Overall, homing ability appears to be widely shared in the family Dendrobatidae, Andinobates being the fourth genus of this family for which homing ability has been corroborated experimentally.

<i>Ichthyology & Herpetology</i> (formerly <i>Copeia</i>) publishes work on the biology of fishes, amphibians, and reptiles, or work using those organisms as models for testing hypotheses of broad significance.

We describe through integrative taxonomy a new Amazonian species of leaf-litter toad of the Rhinella margaritifera species group. The new species inhabits open lowland forest in southwest Amazonia in Brazil, Peru, and Bolivia. It is closely related to a Bolivian species tentatively identified as Rhinella cf. paraguayensis. Both the new species and R. paraguayensis share an uncommon breeding strategy among their Amazonian congeners: each breeds in moderate to large rivers instead of small streams or ponds formed by rainwater. The new species is easily differentiated from other members of the R. margaritifera species group by having a strongly developed bony protrusion at the angle of the jaw, a snout–vent length of 63.4–84.7 mm in females and 56.3–72.3 mm in males, well-developed supratympanic crests with the proximal portion shorter than the parotoid gland in lateral view, a divided distal subarticular tubercle on finger III, and multinoted calls composed of groups of 7–9 pulsed notes and a dominant frequency of 1,012–1,163 Hz. Recent studies have shown that the upper Madeira Basin harbors a megadiverse fauna of anurans, including several candidate species. This is the first member of the R. margaritifera species group to be described from this region in recent years, and at least two additional unnamed species await formal description.

Gobiesocidae are a moderate-sized family (currently 182 species, 51 genera) of predominantly coastal marine fishes, commonly referred to as clingfishes. Depending on the classification adopted, the species and genera of clingfishes are organized either across ten subfamilies, based on a classification scheme introduced in the 1950s (“traditional” classification, comprising Aspasminae, Cheilobranchinae, Chorisochisminae, Diademichthyinae, Diplocrepinae, Gobiesocinae, Haplocylicinae, Lepadogastrinae, Protogobiesocinae, and Trachelochisminae), or just two subfamilies, in a classification scheme adopted only recently (“reduced” classification, comprising Cheilobranchinae and Gobiesocinae). We investigated the phylogenetic relationships among members of the family Gobiesocidae using both mitochondrial and nuclear DNA sequence data to assess whether the alternative classification schemes (traditional and reduced) are compatible with inferred evolutionary relationships. Phylogenetic hypotheses are derived from maximum-likelihood and Bayesian analyses of a seven-gene concatenated dataset (2 mitochondrial and 5 nuclear markers; 4,857 bp) compiled from individuals representing 82 (of 182) species, 42 (of 51) genera, and 10 (of 10) subfamilies of the Gobiesocidae. Although our investigation provides strong support for the monophyly of the Gobiesocidae, multiple subfamilies of the traditional classification (Aspasminae, Diademichthyinae, Diplocrepinae, Gobiesocinae, and Trachelochisminae), one subfamily of the reduced classification (Gobiesocinae), and multiple genera (Aspasmichthys, Cochleoceps, Lepadogaster, and Lepadichthys) are resolved as non-monophyletic groups. Based on our results and the results of previous studies, we recommend a systematic reassignment of genera between subfamilies, of which we recognize nine: Cheilobranchinae, Chorisochisminae, Diademichthyinae, Diplocrepinae, Haplocylicinae, Gobiesocinae, Lepadogastrinae, Protogobiesocinae, and Trachelochisminae. Membership of the Lepadogastrinae is unchanged from previous usage; the Cheilobranchinae are expanded to contain additional genera from southern Australia, including those placed previously in the Aspasminae (Nettorhamphos and Posidonichthys) and the Diplocrepinae (Barryichthys, Cochleoceps, and Parvicrepis); the Aspasminae are placed in the synonymy of the Diademichthyinae and all genera placed in the former (excluding Modicus and Posidonichthys) are transferred to the latter; the Diplocrepinae are restricted to Diplocrepis; Eckloniaichthys scylliorhiniceps is transferred from the Gobiesocinae to the Chorisochisminae; Gobiesocinae are restricted to the New World members of this group (Acyrtops, Acyrtus, Arcos, Derilissus, Gobiesox, Rimicola, Sicyases, and Tomicodon); the Haplocylicinae are expanded to include additional genera from New Zealand (Gastrocyathus, Gastrocymba, and Gastroscyphus); the Protogobiesocinae are expanded to accommodate three genera of deep water taxa (Gymnoscyphus, Kopua, and Protogobiesox); and the Trachelochisminae are restricted to Dellichthys and Trachelochismus. Four genera (Aspasmogaster, Conidens, Creocele, and Modicus) of uncertain placement are not assigned to any subfamily herein and are considered incertae sedis within the Gobiesocidae.

A new species of colorful snakehead from Meghalaya, northeastern India is distinguished from all its congeners by possessing a uniform bright blue to bluish-green body, bright-blue dorsal, anal, and caudal fins, submarginally black with white distal margin, series of brown to maroon-red, rounded, oblong or clover-shaped blotches or spots on dorsolateral, postorbital, and ventrolateral region of head, continued on body forming oblique pattern or randomly distributed. The new species superficially resembles C. pardalis and C. bipuli in appearance, but it can be distinguished from both in having brown to maroon-red, rounded, oblong or clover-shaped blotches or spots on head and sides of the body (vs. possession of well-defined, black to brown, rounded to oblong spots), fewer pre-dorsal scales (7 vs. 8–9), more caudal-fin rays (15 vs. 13), and more vertebrae (49 vs. 45). The new species differs from both C. pardalis and C. bipuli by Kimura's two-parameter (K2P) distance of 4.2–4.8 and 4.9–6.0% in the coxI gene sequence. A key to the snakehead Gachua group of the Eastern Himalayan region is provided herein.

The Philippine archipelago is an exceptionally biodiverse region that includes at least 112 species of land snakes from 41 genera and 12 families. Recently, Cyclocoridae (formerly Lamprophiidae: Cyclocorinae) was proposed as a distinct, Philippine-endemic family, containing four genera: Cyclocorus, Hologerrhum, Myersophis, and Oxyrhabdium. Here, we describe an additional cyclocorid genus and species, Levitonius mirus, new genus and species, from Samar and Leyte Islands, Philippines. Molecular data support Levitonius, new genus, to be most closely related to Myersophis and Oxyrhabdium, and it shares multiple skeletal characteristics with these genera; Levitonius, new genus, differs from all of these taxa in body size, scalation, and other characters. Skeletal and other phenotypic data suggest that Levitonius, new genus, is fossorial and likely has a diet that is specialized on earthworms. Levitonius mirus, new genus and species, has a maximum total length of 172 mm and is at present the smallest known species in Elapoidea. Our results highlight the need for future work on Samar and Leyte Islands, which have received relatively little attention from systematists, in part because of a prevailing biogeographic paradigm that predicted (not necessarily correctly) that these islands would simply have a nested faunal subset of the Mindanao faunal region land vertebrates. The discovery of a strikingly distinct and phylogenetically divergent snake lineage on these landmasses joins numerous related studies calling for a wholesale reconsideration of the Pleistocene Aggregate Island Complex model (the PAIC paradigm of diversification) biogeographic framework.

We describe a new species of the South American frog genus Adenomera, based on external morphology, color patterns, advertisement call, and mtDNA sequences. The new species was collected from the Japurá River basin in northwestern Brazilian Amazonia and is distinguished from all congeners by the combination of large snout–vent length (SVL), toe tips unexpanded, presence of antebrachial tubercle on underside of forearm, and by a multi-note advertisement call composed of non-pulsed notes. This new species is part of the A. lutzi clade together with a candidate new species known as Adenomera sp. P and A. lutzi. The three species have the largest SVL in the genus. The presence of toe tips fully expanded and a single-note advertisement call distinguish A. lutzi from the new species. Acoustic and morphological data are still required to assess the taxonomic identity of Adenomera sp. P. Our new species of Adenomera is the third anuran species described from the Solimões-Japurá interfluve. This flags this poorly known region of lowland forests as an important area of species richness in northwestern Amazonia.