Since the first documented declines of amphibian species, researchers have learned how nonnative species can depress amphibian populations and lead to local extinctions. Here, we explore the dimensions of invasions in the context of evolutionary history, anthropogenic disturbance, and climate change. Recent studies indicate that the nonnative groups that have most negatively affected amphibians are plants, fishes, and other amphibians. We review current work aimed at determining the direct and indirect effects of nonnative species on amphibian health, genotypes, and native ecosystem structure, as well as research examining invasions from a community level perspective. We also describe synergistic effects between abiotic, biotic, and nonnative factors. Recent studies have documented the intricacies of invasions and how numerous aspects of invasions can interact additively and complementarily to the detriment of the native ecosystem. Understanding the complexity of invasions means considering if and how biological, environmental, and ecological processes within ecosystems are being reshaped as a result of introduced species. Assessing the ecology and ecosystem dynamics of invasions at multiple levels, from the genome to the ecosystem, is paramount to the conservation, restoration, and future research of invaded amphibian ecosystems.

As part of a revision of the cichlid genus Archocentrus, a new genus, Amatitlania, was erected comprising four species: A. nigrofasciata (the type species), A. siquia, A. kanna, and A. coatepeque. Amatitlania coatepeque is an endemic and an eponym of Lago Coatepeque in the interior highlands of western El Salvador. This species was diagnosed by a Y-shaped pattern formed by the ventral fusion of bars four and five on the body; a triple-spined, squarish, or blunt appearance of the dentigerous arm of the dentary; the presence of a posterior projection at the dorsal corner of the lower lip; the presence of a double medial-loop in the gut; sparsely uniform pigmentation of the peritoneum, and 5–5.5 scale rows from the lateral line to the origin of the dorsal fin. Here we examined the taxonomic status of A. coatepeque using molecular and morphological characters. We found that A. coatepeque is phylogenetically nested within the clade of A. nigrofasciata. Additionally, our re-examination of the reported diagnostic morphological characters failed (even in combination) to diagnose A. coatepeque. We instead found that some of those characters were highly variable within A. coatepeque and are sometimes present in members of A. nigrofasciata. Based on our results, we conclude that A. coatepeque is a junior synonym of A. nigrofasciata.

Como parte de un revisión del genero de ciclidos Archocentrus, un nuevo género (Amatitlania) fue descrito e incluye cuatro especies: A. nigrofasciata (la especie tipo), A. siquia, A. kanna, y A. coatepeque. Amatitlania coatepeque es endémica y un epónimo del Lago Coatepeque que se localiza en las tierras altas en el interior del oeste de El Salvador. Esta especie fue diagnosticada por una banda en forma-Y formada por la fusión ventral de las barras 4 y 5 en el lado del cuerpo; un dentario romo, triplemente-espinado y más o menos cuadrado; la presencia de una proyección posterior en la esquina dorsal del labio inferior; la presencia de un circulo-medial doble en el intestino, pigmentación uniformemente dispersada pero escasa en el peritoneo y 5–5.5 líneas de escamas desde la línea lateral al origen de la aleta dorsal. En este estudio con el uso de caracteres moleculares y morfológicos examinamos el estatus taxonómico de A. coatepeque. Encontramos que A. coatepeque filogenéticamente se encuentra anidada dentro de clados de A. nigrofasciata. Adicionalmente, la re-examinación de los caracteres morfológicos utilizados para diagnosticar la especies fallaron (aun en combinación) en diagnosticar A. coatepeque. Al contrario, nosotros encontramos que algunos de estos caracteres fueron altamente variables dentro de A. coatepeque y algunas veces están presentes en miembros de A. nigrofasciata. Basados en nuestros resultados nosotros concluimos que A. coatepeque es un sinónimo juvenil de A. nigrofasciata.

The Cottonmouth, Agkistrodon piscivorus, is a semi-aquatic pitviper that occupies the southeastern U.S. west into Texas. Several previous studies have investigated the biogeographic history of A. piscivorus. It has been hypothesized that A. piscivorus was split into two separate populations during the last glacial maximum and climate change has impacted its distribution. Additionally, a geographically isolated population of A. piscivorus occurs at the western limit of the species' range in the Concho Valley of Texas. To investigate biogeography and population structure within A. piscivorus in Texas and throughout its range, we utilized amplified fragment length polymorphism (AFLP) and sequence data from cytochrome b (cyt-b). The AFLP data indicate a lack of gene flow between the population of A. piscivorus in the Concho Valley and other nearby populations. However, based on cyt-b, there is no genetic differentiation. The AFLP data for the entire species show a signature of two historic populations that have recently come into secondary contact. Finding two historic populations is consistent with previously published data based on mitochondrial DNA analyses; however, due to the rapid evolution rate of AFLP data, we were able to detect a high level of gene flow between these populations. We conclude that it is possible Texas and Florida served as refugia for A. piscivorus during the last glacial maximum, and, as the glaciers receded, the two populations expanded, coming into secondary contact. The subsequent gene flow has resulted in shared loci across the two populations. The difference between the conclusions drawn between our two markers and previous research is due to the different time scales that AFLP and cyt-b markers measure. The AFLP data provided a contemporary marker and cyt-b indicated historic separation.

Toe clipping is commonly used to identify individual frogs in mark–recapture studies. However, Institutional Animal Care and Use Committees (IACUCs) often have reservations about approving studies that include toe clipping as a way to mark animals. Previous studies indicate that recapture rates of terrestrial frogs and toads decrease with increasing numbers of toes clipped. It is not known whether these decreases are due to decreased survival rates, increased avoidance of recapture, or some other reason. The goal of this paper is to provide IACUCs with a quantitative analysis of the effects of toe clipping on survival so that they can make informed, data-based decisions when approving studies using this method, rather than basing decisions on anthropomorphic biases. We conducted a large (n  =  100) laboratory experiment to determine the effects of toe clipping on the frog Rana pipiens. We found no evidence that the number of toes clipped affected either the survival rate of Leopard Frogs or the number of days that frogs survived over a 13-week period.

Lake Trout (Salvelinus namaycush) spawn in fall and hatch in spring; to protect their eggs over the winter they spawn on rocky reefs, where the eggs settle deeply into interstices. Uptake of water swells the eggs, further protecting them by lodging in crevices. Freshwater sculpin (Cottidae), the primary predator of salmonid eggs, are small, benthic fishes with malleable bodies and large heads. To acquire the lipid-rich resource contained in eggs, sculpin must penetrate deeply into interstices, and have a method to extract lodged eggs. We placed Slimy Sculpin (Cottus cognatus) into a tunnel containing a sequence of funnels with progressively smaller openings to determine the smallest hole they could enter. Forty-three of 138 Slimy Sculpin (31%) moved through openings up to 19.7% smaller than the maximum width of their head, indicating that they compressed their skull to move through the opening. We examined egg acquisition behavior by placing Lake Trout eggs into holes drilled in a Plexiglass plate. Holes varied in diameter from 5.6 to 8.7 mm, and were either shallow (5 mm) or deep (9 mm); after water hardening, eggs were lodged in the smallest holes and loose in the larger holes. Sculpin consumed eggs in the large, shallow holes first, then used suction to extract eggs from small, shallow holes. To extract eggs from small, deep holes, they used a sequence of suction attempts to draw the eggs upward. Sculpin are highly adapted to forage on Lake Trout eggs, including the novel capacity to compress their skulls to access eggs.

Increasing salinity in freshwater habitats is an emerging threat in both coastal and inland environments. In addition, pesticides can be harmful to aquatic organisms and have been detected worldwide in aquatic systems. Both of these changes can strongly affect amphibians, as they typically rely on aquatic environments. With external fertilization, the selection of an oviposition site can be crucial for ensuring fertilization success and for providing offspring with a hospitable environment for development. We examined the effects of increased salinity and a commonly applied insecticide, carbaryl, on sperm activity and oviposition site selection of the Green Treefrog (Hyla cinerea). Sperm motility and velocity both decreased as salinity concentration increased but showed no effect of carbaryl at concentrations at and above those expected in the environment. Artificial pools with weakly brackish water received less oviposition than did freshwater pools. Carbaryl also inhibited oviposition, but only when pools had been freshly dosed. These findings suggest that increased salinity may negatively affect reproductive success in H. cinerea through its effect on sperm function, but that individuals may be able to avoid these costs by selectively ovipositing in freshwater. Although carbaryl did not influence two measures of sperm movement, selective oviposition may help adults to avoid habitats that could be harmful to their developing offspring. Thus, selective oviposition may increase the ability of amphibian populations to persist in degraded habitats, as long as some suitable sites are still available.

The second known species in Barchatus is described from Somalia, in the Gulf of Aden. Compared to the other known species, B. cirrhosus from the Red Sea, B. indicus has two tentacles above the eye, whereas B. cirrhosus only has one large tentacle, and the anterior nares with long and pointed tentacles (distal 70% narrow; shorter and wider [distal 35% narrow] in B. cirrhosus). Barchatus indicus is only known from the Gulf of Aden, Somalia.

A new neoplecostomine genus and species is described from headwater tributaries of the lower Rio Pardo basin, a coastal drainage in Bahia, eastern Brazil. Hirtella carinata is a small loricariid with a maximum standard length barely reaching 50 mm. The new genus and species are diagnosed among all other loricariids by a unique, remarkable pattern of sexual dimorphism in which adult males have five conspicuous longitudinal rows of bristle-like hypertrophied odontodes on the head and along the lateral dermal plates of the body. Hirtella is further distinguished from most loricariids by the anterior position of the pelvic fin, which originates in a vertical anterior to the nuchal plate, and by the possession of an elongate keel formed by 15–17 azygous plates along the mid-dorsal line between the dorsal and the caudal fins. Hirtella is additionally distinguished from other members of the Neoplecostominae by having a medium sized palatine splint, never reaching the anterior border of the nasal fossa. Phylogenetic analysis indicates that Hirtella is the sister taxon of Pareiorhina. The description of this new genus raises to six the number of currently recognized genera in the Neoplecostominae.

Um novo gênero e espécie de neoplecostomíneo é descrito das cabeceiras de tributários do baixo Rio Pardo, drenagem costeira da Bahia, leste do Brasil. Hirtella carinata é um pequeno loricarídeo que atinge quase 50 mm de comprimento padrão. O novo gênero e espécie são diagnosticados de todos os demais loricarídeos por um único e notável padrão de dimorfismo sexual, em que os machos adultos possuem um conjunto de odontódeos hipertrofiados na cabeça e ao longo das placas laterais do corpo que formam cinco linhas longitudinais evidentes. Hirtella é também distinguido da maioria dos loricarídeos pela posição anterior das nadadeiras pélvicas, que se originam em uma vertical anterior a placa nucal e pela presença de uma longa quilha formada por 15–17 placas ázigas na linha média dorsal, entre as nadadeiras dorsal e caudal. Hirtella é ainda distinguido dos outros membros de Neoplecostominae por ter o palatine splint de tamanho médio, nunca alcançando a borda anterior da abertura nasal. A análise filogenética atual indica que Hirtella é o táxon irmão de Pareiorhina. A descrição desse novo gênero eleva para seis o número de gêneros atualmente reconhecidos em Neoplecostominae.

In December 1982 a devastating flood occurred in Piney Creek, in the rural Ozark Mountains in Izard County, Arkansas, with vertical stage rises of 2–4 m in the headwaters, 11–12 m at downstream locations, and an estimated return time of 50–100 years. Physical effects in the watershed were catastrophic, with extreme scour and rearrangement of the stream bed, destruction of riparian forest, and deposition of huge amounts of sand from the creek in adjacent pastures or forest. In spite of the extreme nature of this winter flood, residual effects on the overall fish community of the watershed were minimal, and by eight months after the event, the community was virtually indistinguishable from that in the previous summer. In March–April 2008 flooding of equal or greater magnitude than the 1982 flood again occurred in Piney Creek. We followed effects of the spring 2008 flood on local fishes at five long-term fixed sites in the watershed, and on the fish community pooled across those sites, four months after the 2008 flood, and again in 2010 and 2012. In spite of the severity of the 2008 springtime flood, the community before and after was relatively similar qualitatively and quantitatively. But multivariate analyses of the fish community showed more change after the 2008 flood, and in a directional trajectory, than had occurred after the 1982 flood. At the five individual sites, changes in fishes after the 2008 flood were idiosyncratic, with two sites showing marked changes immediately after the flood, with only one subsequently returning toward its former structure. Fishes at all five sites showed more change in multivariate space after the 2008 than after the 1982 flood. In the summers after both floods some cyprinid and catostomid species showed sharp increases in numbers of young-of-year. Differences in the effects of the two floods on the fish community could relate to their timing, with springtime flooding having more effects on fish than the winter flood. Similarities between the two floods with respect to increased production of young-of-year could relate to the scouring of fines (silt and sand) by the floods, providing clean gravel and cobble with more interstitial spaces that could provide protection for fish eggs or larvae, and more microhabitat for food organisms used by young fishes such as micro- or macroinvertebrates. Regardless of mechanisms, much remains to be learned about the effects of extreme floods on stream fish communities, particularly in light of the potential for increased frequency of extreme events as global climate changes continue.

The distribution and genetic structure of wildlife populations may be impacted by landscape features and anthropogenic factors. The role of these factors in the genetic relationships among Timber Rattlesnakes (Crotalus horridus) from 21 locations in Pennsylvania, New Jersey, and Virginia was investigated using microsatellite genetic markers. Evidence for null alleles was found in 8 of the 21 populations studied, with frequencies ranging from 0.018 to 0.185. However, the presence of null alleles appeared to have no effect on the interpretation of the patterns of genetic relationships among the populations studied. The analyses showed that the overall extent of genetic differentiation was consistent with isolation by distance; however, a substantial amount of among-groups variation could not be accounted for by geographic distance alone. Bayesian analysis (STRUCTURE), genetic distance analysis, and factorial correspondence analysis (FCA) all indicated that the sampled populations represented three genetic groups, which corresponded closely with physiographic regions. These three groups consisted of an Atlantic Coastal Plain group, an Appalachian Plateau group, and an Appalachian Ridge and Valley group. We recommend that these be considered as separate conservation management units (MUs) for C. horridus in Pennsylvania and New Jersey. Several potential barriers to gene flow were identified, including the Appalachian Mountains, several large rivers, and major roadways. The lowest levels of genetic variation were found in the highly isolated populations from the Atlantic Coastal Plain.

Detailed studies of the population structure of most species of turtles in the Amazon Basin are lacking throughout their range. We estimated sex ratio, size structure, relative abundance, and recapture index for the Giant South American River Turtle (Podocnemis expansa) in Javaés River, southern Brazilian Amazon. Field work was conducted between 2004 and 2009, and comprised a total sampling effort of 368 hours in 92 sampling days. Turtles were captured by diving and seining. A total of 645 individuals (156 adult males, 109 adult females, and 380 juveniles) were captured and marked, but only five were recaptured. Carapace length showed a unimodal pattern for males, but no clear pattern for females. The population consisted predominantly of adult males and young females, with a sex ratio of 1.4:1 (M:F). Relative abundance varied from 0–5.5 animals/h depending on the capture method employed. Most animals (73.7%) were concentrated in a single location on the river (1 km out of 40 km sampled) during the study period. Population monitoring on a long-term basis will be necessary to identify the real population structure, evaluate poaching pressure, and to support the conservation project which has been ongoing since 1985 in the area.

In the bi-directionally hermaphroditic fish, Lythrypnus dalli, two distinct male phenotypes have been described. The more conspicuous parenting males are larger, establish breeding territories, and display courtship, mating, and parenting behaviors. The alternative males, called mini males, have been postulated to have a parasitic reproductive strategy, although the behavioral ecology of mini males is not well understood. The mini male morph has been characterized based on size and anatomical differences, including sperm-filled accessory gonadal structures (as opposed to mostly mucous in nesting males), consistent with parasitic male morphs in other gobiid species. Here, we determined the endocrine profiles of mini males to gain further insight into their phenotype. Systemic (water-borne) 17β-estradiol (E₂) concentrations were higher than testosterone (T), and 11-ketotestosterone (KT) concentrations were lowest. Mini males in L. dalli are similar to parasitic males of other species in having higher T∶KT ratios than breeding males. In mini males, brain and reproductive tissue levels of T, E₂, and KT were higher than in the muscle. Among all the steroids, E₂ levels were high in all three tissues in mini males. Data from relative hormone levels in different tissues will lead to a better understanding of the endocrine regulation of behavioral, physiological, and morphological correlates of male sexual polymorphism.

Map turtles of the genus Graptemys are highly aquatic and rarely undergo terrestrial movements, and limited dispersal among drainages has been hypothesized to drive drainage-specific endemism and high species richness of this group in the southeastern United States. Until recently, two members of the megacephalic “pulchra clade,” Graptemys barbouri and Graptemys ernsti, were presumed to be allopatric with a gap in both species' ranges in the Choctawhatchee River drainage. In this paper, we analyzed variation in morphology (head and shell patterns) and genetics (mitochondrial DNA and microsatellite loci) from G. barbouri, G. ernsti, and Graptemys sp. collected from the Choctawhatchee River drainage, and we document the syntopic occurrence of those species and back-crossed individuals of mixed ancestry in the Choctawhatchee River drainage. Our results provide a first counter-example to the pattern of drainage-specific endemism in megacephalic Graptemys. Geologic events associated with Pliocene and Pleistocene sea level fluctuations and the existence of paleo-river systems appear to have allowed the invasion of the Choctawhatchee system by these species, and the subsequent introgression likely predates any potential human-mediated introduction.

Due to an intense level of interest from the media, the public, conservation NGOs, and policymakers, the scientific study of charismatic megafauna is perceived by some researchers as associated with glory-seeking or other less-than-noble behavior. However, the study of elasmobranchs has led to important discoveries in the fields of physiology, evolution, neurobiology, behavior, and ecology that would not have been possible with other study systems. These animals are ecologically and economically important, and many species are of great conservation concern. Additionally, public interest in these animals can be leveraged for science and conservation education and outreach efforts, and they can be used as “flagship species” for conservation and management policy. In this paper, we discuss the value of taxon-focused scientific research using examples from the work of American Elasmobranch Society scientists. We argue for the importance of taxon-based societies, such as the American Elasmobranch Society (AES), and the societies it meets jointly with, including the American Society of Ichthyologists and Herpetologists, the Society for the Study of Reptiles and Amphibians, and the Herpetologists' League. Together these four societies make up the Joint Meeting of Ichthyologists and Herpetologists (JMIH). While this paper will focus on AES, the general principles apply broadly to all members of JMIH as well as other taxon-based societies, and speak to their importance amongst a backdrop of broadly discipline-based research societies.