A new crocodylid is described on the basis of fragmentary, but diagnostic, material from the Quaternary of Aldabra Atoll. It differs from all other known crocodylians, living or extinct, in having a prominent semicircular crest, or “horn,” on the dorsolateral margin of the squamosal. Unlike the horns seen in some living Crocodylus, the apex of each horn was at its midpoint anterior to the external otic aperture and not near its posterior end. It also has a highly vaulted premaxillary palate and an anterodorsally-oriented external naris, and dorsal exposure of the supraoccipital on the skull table was extensive. Phylogenetic relationships of the new form are unclear, making its biogeographic origins difficult to trace, but it was very likely an immigrant from elsewhere and not endemic to Aldabra Atoll, as it occurs in deposits formed shortly after a period of submergence ended 120,000 years ago.

Blanchard's Cricket Frogs (Acris crepitans blanchardi) are geographically widespread and historically common, yet they are in decline throughout much of the northern part of their range. One proposed mechanism for this decline is the negative effects of acidified precipitation on this acid-sensitive species. To test the predictions of this hypothesis, we sampled 570 randomly-selected sites along three transects in Ohio using chorusing surveys during 2004. Along these transects, we assessed pH and acid neutralizing capacity (alkalinity), as well as terrestrial and aquatic vegetation cover. Our surveys detected 53 extant Cricket Frog populations (9.3% of surveyed sites) in ponds, lakes, and streams. These sites were exclusively located in western Ohio, indicating a substantial (120 km) range contraction, compared to its historic distribution in the state. A multiple logistic regression model found no significant relationship between Cricket Frog occurrence and either pH or acid neutralizing capacity (P > 0.50). Acid neutralizing capacity and pH were also not significantly different in extant and extinct areas of the Cricket Frog's range in Ohio (P > 0.05). Cricket Frogs were found to occur significantly more frequently than expected by chance in lakes and at sites with low canopy cover (P < 0.001). While synergistic interactions with other factors cannot be ruled out, these results suggest that habitat acidification is likely not responsible for Cricket Frog declines in Ohio. Unlike other declining amphibians, where likely causal mechanism(s) have been identified, causes of Cricket Frog declines remain enigmatic.

The neotropical auchenipterid catfish genus Tetranematichthys is reviewed. Tetranematichthys was previously thought to be monotypic with its single species, T. quadrifilis, reported to have a broad range encompassing major portions of the Amazon basin and southern tributaries of the Río Orinoco. Tetranematichthys quadrifilis was rather found to be endemic to the Rio Guaporé in the southwestern portions of the Amazon basin and a new species of the genus is described from material originating in the upper Rio Negro system in Brazil and Venezuela and the upper Río Orinoco basin in southern Venezuela. The new species is also apparently widespread within the Amazon basin and the southern and north-central portions of the Río Orinoco system. The species of Tetranematichthys have distinctive modifications of the mandibular barbel and associated systems, which are proposed as synapomorphic for the species of the genus and that potentially function as a fishing lure.

Our ability to understand predator-prey systems is often limited by a lack of detailed information on fundamental aspects of organismal natural history. It is particularly difficult to gather quantitative data on the behavior of sit-and-wait predators, which are generally secretive and feed infrequently. In this study I use video surveillance equipment to record natural interactions between a predator, Crotalus horridus, and its prey. From observations of 17 individuals over two years, a total of 87 encounters with prey were recorded, with snakes successfully attacking 13% of prey items that came within striking distance. Snakes stayed at ambush sites for a mean of 17 hours and were estimated to feed between 12 and 15 times over the course of a season, consuming between 1250 and 1550 g of prey per snake, mostly woodland rodents (Peromyscus, Microtus, Clethrionomys, Tamias, and Sciurus). These data represent some of the most detailed quantitative measures on snake foraging behavior and predator-prey interactions available and can be used to inform general ecological and behavioral models in similar systems.

Chytridiomycosis is an emerging infectious disease of amphibians caused by the fungal pathogen Batrachochytrium dendrobatidis, and its role in causing population declines and species extinctions worldwide has created an urgent need for methods to detect it. Several reports indicate that in anurans chytridiomycosis can cause the depigmentation of tadpole mouthparts, but the accuracy of using depigmentation to determine disease status remains uncertain. Our objective was to determine for the Mountain Yellow-legged Frog (Rana muscosa) whether visual inspections of the extent of tadpole mouthpart depigmentation could be used to accurately categorize individual tadpoles or R. muscosa populations as B. dendrobatidis-positive or negative. This was accomplished by assessing the degree of mouthpart depigmentation in tadpoles of known disease status (based on PCR assays). The depigmentation of R. muscosa tadpole mouthparts was associated with the presence of B. dendrobatidis, and this association was particularly strong for upper jaw sheaths. Using a rule that classifies tadpoles with upper jaw sheaths that are 100% pigmented as uninfected and those with jaw sheaths that are <100% pigmented as infected resulted in the infection status of 86% of the tadpoles being correctly classified. By applying this rule to jaw sheath pigmentation scores averaged across all tadpoles inspected per site, we were able to correctly categorize the infection status of 92% of the study populations. Similar research on additional anurans is critically needed to determine how broadly applicable our results for R. muscosa are to other species.

A new diagnosis for the trichomycterid genus Henonemus based on external characters is offered, and Henonemus triacanthopomus, new species, is described from the Orinoco River basin in Venezuela. The new species is distinguished from the other species of the genus by three or asymmetrically four opercular odontodes in specimens longer than 80 mm SL, a blackish ventral lobe of caudal fin, a row of mid-lateral dark blotches above the lateral line deflected dorsally on caudal peduncle, five interopercular odontodes inserted in the main series, and lower jaw teeth arranged in seven rows. Additionally we discuss the characters of external morphology that support monophyly of Henonemus, a less inclusive group within Stegophilinae comprising Acanthopoma, Apomatoceros, Henonemus, Megalocentor, Pareiodon, Parastegophilus, and Pseudostegophilus and a sister group relationship between Acanthopoma and Henonemus.

Una nueva diagnosis para el género tricomictérido Henonemus basada en caracteres externos es ofrecida en el presente trabajo y se describe Henonemustriacanthopomus, especie nueva, para la cuenca del río Orinoco en Venezuela. La nueva especie se diferencia de las demás especies del género, por la presencia de tres o asimétricamente cuatro odontodes operculares en ejemplares mayores de 80 mm LE y por presentar el lóbulo ventral de la aleta caudal negruzco, la hilera media lateral de manchas situada encima de la línea lateral y desviada dorsalmente en la región del pedúnculo caudal, cinco odontodes interoperculares insertados en la serie principal y dientes de la mandíbula inferior dispuestos en siete hileras. Adicionalmente se discuten los caracteres de la morfología externa que soportan la monofilia de Henonemus, un grupo menos inclusivo dentro de Stegophilinae conformado por Acanthopoma, Apomatoceros, Henonemus, Megalocentor, Pareiodon, Parastegophilus y Pseudostegophilus y una relación de grupo hermano entre Acanthopoma y Henonemus.

The morphology, topological relationships, and innervation patterns of m. cervicoquadratus in various snakes, especially basal taxa, were examined. Nearly all aspects of its anatomy suggest that this muscle is homologous with a part of m. cucullaris, most likely m. episternocleidomastoideus, the muscle that connects the skull and pectoral girdle in non-ophidian squamates. This is the first report of any pectoral girdle muscle persisting in snakes. In snakes examined, the most posterior extent of m. cervicoquadratus does not extend more posteriorly than the level of the 11th precloacal vertebra, suggesting that the length of the neck inferred on this characteristic would be quite short compared to the length of the entire precloacal region. However, different anatomical and developmental characteristics are known to indicate various lengths of the neck in snakes. This suggests that such characteristics potentially evolve independently from one another, and thus no single criterion may be sufficient to delimit the neck in snakes.

Whole-animal performance traits, such as locomotor performance, are central to current concepts of phenotypic adaptation, yet the possible evolution of such traits via sexual selection is an underexplored hypothesis. We studied a cursorial, polygynous, territorial lizard to test two predictions of sexual selection theory applied to whole-animal performance: a secondary sexual performance characteristic may be sexually dimorphic, and variation in performance among males should be correlated to mating success. Maximal sprinting performance was measured in a series of wild-caught adult collared lizards (Crotaphytus collaris) from a single Oklahoma population. Sprint speed varied repeatably among individuals, but did not scale to body size among adults. Contrary to our first prediction, sprint speed did not differ between sexes. However, among 11 adult males sprint speed was strongly correlated to territory size and a spatial index of potential mating success (independent of body size), which indicates phenotypic intrasexual selection, whether direct or indirect, for whole-animal locomotor performance. The lack of sexual dimorphism in sprint speed may reflect trade-offs with other sexually selected traits (e.g., head size) and/or condition-dependence of running capability. Sexual selection of social behavior may underlie more generally the evolution of physiological performance, and therefore of suborganismal physiology and morphology.

Eptatretus goliath new species, is described from a specimen caught at the head of the Hauraki Canyon off the northeast North Island, New Zealand, at 811 m depth. It differs from all other seven-gilled Eptatretus in having three-cusp multicusps in anterior and posterior rows, 11–13 unicusps in anterior rows, nine unicusps in posterior rows, total cusps 54, 14–15 prebranchial pores, 57–58 trunk pores, 13–14 tail pores, 92 total pores, and a prominent ventral finfold. The single specimen, at 1275 mm TL and 6.2 kg, is the largest hagfish yet known.

Symphurus monostigmus, described on the basis of two males (48.8 and 54.6 mm SL) collected on the inner continental shelf at 65–110 m off the coast of KwaZulu-Natal, South Africa, is distinguished from congeners by the following combination of characters: an irregular, conspicuous dark spot overlying the anteroventral ocular-side body cavity; a 1-2-2-2-2 pattern of interdigitation of dorsal-fin pterygiophores and neural spines; 14 caudal-fin rays; 86 dorsal-fin rays; 73–74 anal-fin rays; 48 total vertebrae; five hypurals; black peritoneum (posterior region only); ocular side uniformly yellowish-white with numerous, darker reddish-brown freckles especially noticeable along dorsal and ventral contours of body (freckles coalesced into several darker blotches on dorsal and ventral margins on posterior half of body), blind side uniformly yellowish-white, and dorsal and anal fins without conspicuous spots or ocelli. Symphurus monostigmus is most similar to S. macrophthalmus, but differs from that species in ID pattern (1-2-2-1-2 in S. macrophthalmus) and its smaller eye (100–138 vs. 211 in thousandths of HL) with much smaller pupil (pupil diameter/eye diameter 28–32% vs. ca. 54% in S. macrophthalmus).

Collecting by Alcide D'Orbigny in the western South Atlantic provided material for Platessa orbignyana Valenciennes, 1839, published as an illustration of the holotype without accompanying descriptive information. A brief and inadequate description was provided in 1847. Thereafter, the holotype was thought to be lost, precluding comparative study and resulting in nomenclatural confusion for other nominal paralichthyid species. A specimen of Paralichthys collected in the Río de la Plata, Buenos Aires, Argentina by D'Orbigny at the Muséum national d'histoire naturelle (MNHN 1999-0295) is here identified as the holotype of Platessa orbignyana Valenciennes, 1839. A redescription of the holotype and comparison with other South Atlantic species resolves several nomenclatural issues.

A new killifish species, Aphanius isfahanensis, is described from the Isfahan basin of Iran. It is distinguished from the other Iranian species of Aphanius by adult color pattern, molecular character states of mitochondrial DNA sequence data, and in multivariate morphometric and meristic space. Based on the phylogenetic analysis of molecular sequence data, the new species is hypothesized to be sister taxon to A. sophiae plus A. persicus, which also occur in Iran.

The karyotype of the genus Caudacaecilia is first reported on the basis of C. asplenia from Sabah, Malaysia. The species has 2n  =  42 chromosomes, consisting of two pairs of biarmed macrochromosomes, eight pairs of biarmed microchromosomes, and 11 pairs of uniarmed microchromosomes. These karyotypic characteristics do not differ from those of Ichthyophis, the other genus of Ichthyophiidae. We also provide the first documented account of the presence of splenial teeth in larval Caudacaecilia.

Relative to mainland Boa constrictor, boas from islands off the coast of Belize are described as being smaller, having longer tails, more elongate snouts, and proportionately larger eyes. However, no systematic confirmation of these patterns has been made. A morphometric study was initiated to investigate the body size and head shape variation between island and mainland boas in Belize. One hundred twenty-nine boas from five islands and the mainland were caught and measured. Univariate and multivariate analyses indicated that, in general, previous descriptions are accurate. Island boas are about half the length and one-fifth the mass of mainland boas. In contrast to mainland boas, no sexual size dimorphism is evident in island boas. The head shape of island boas differs from that of mainland boas but this divergence is not consistent among populations. Some island boas have more attenuate snouts compared to mainland boas whereas other island boas have larger eyes and narrower heads. Male island boas have longer tails compared to males from the mainland, but such a difference is not found in females from the two localities. The morphology of island boas is consistent with an arboreal habit and reduced prey size. Because these changes have occurred over an extremely short time interval, this may be another example of the speed and magnitude of adaptation that is possible in squamates.

The diet of the Common Map Turtle (Graptemys geographica) was studied in Lake Erie habitats associated with a Pennsylvania sandspit peninsula. Three taxa predominated in fecal samples: trichopteran larvae (principally leptocerids), gastropods, and Zebra and Quagga Mussels (Dreissena spp.). Pronounced sexual and size-related differences occurred for these taxa, as adult males fed primarily on trichopterans and snails, while the larger females fed almost exclusively on Dreissena spp., with prevalence of Dreissena spp. increasing with body size. Dietary data from habitats lacking invasive mollusks suggest that the overall reliance on mollusks in the diet may have increased since the invasion of Lake Erie by Dreissena spp. Results are similar to earlier reports concerning the effect of invasive Asian Clams (Corbicula spp.) on decreasing dietary diversity in females of many populations of the four species of Graptemys that have mollusk-adapted mesocephalic females.

Procambarus clarkii, an American crayfish, was introduced in the SW Iberian Peninsula three decades ago. This region has no native crayfishes; therefore, P. clarkii constitutes a potential threat for the embryos and larvae of amphibians, which may lack evolved defenses against it. We assessed the effects of this crayfish on the Natterjack Toad, Bufo calamita, using two complementary approaches. First, we studied the effect of crayfish presence on B. calamita breeding habitat use in temporary ponds of Doñana Natural Park (southwestern Spain). We surveyed 31 temporary ponds for the presence of P. clarkii and B. calamita eggs and tadpoles, and we conducted a logistic regression to determine if crayfish were significantly associated with Natterjack Toad distribution after habitat variables were taken into account. Second, we experimentally evaluated the impact of P. clarkii on B. calamita embryos in natural ponds with a two × two factorial experiment, using two ponds (one with and one without crayfish) and two treatments (embryos exposed or not exposed to predators). Crayfish presence was a negative predictor of B. calamita breeding habitat use; co-occurrence of the two species was limited to only one pond. Moreover, the predation experiment showed that survival of B. calamita embryos was strikingly reduced when they were directly exposed to crayfish compared to survival in all other treatments. Our results indicated that P. clarkii has a strong effect on B. calamita reproductive success and that it may play an important role in structuring amphibian communities in temporary ponds.

Turtles are in decline world-wide, and few studies have collected the long-term, age-specific demographic data needed to identify species-specific life history stages critical to population viability and conservation. Here I report estimates of birth and death rates, survivorship, and longevity of Spotted Turtles (Clemmys guttata) using modified logarithmic decay equations and 24 years of mark-recapture data collected from a population at the northern extreme of the species' range. The recruitment rate was more than twice the mortality rate. Spotted Turtle survivorship and longevity estimates are among the highest values reported for any animal species, and females are significantly more long-lived than males. Minimum annual adult female survivorship is 96.5%, maximum longevity is 110 years, and age at maturity is 12 years. Minimum male survivorship is 94.2%, maximum longevity is 65 years, and age at maturity is 11 years. This ongoing study is the longest-running on Spotted Turtles, yet insufficient age-specific data have been gathered to construct a life table, particularly because egg and hatchling survival rates remain unknown; future work should specifically focus on gathering such data. The results of the current study have important management implications when considering which life history stages to protect for maintenance of population viability of long-lived vertebrates.

Image analysis was used to measure feeding angles of Labeotropheus trewavasae, Labeotropheus fulleborni, Melanochromis auratus, Metriaclima zebra, Petrotilapia spp., Pseudotropheus c.f. elongatus, Tropheops tropheops, and Tropheops gracilior videotaped in Lake Malawi. Petrotilapia spp. fed on vertical, slanted, and horizontal slopes, T. gracilor grazed on vertical slopes approximately 60% of the time, and the other species spent at least 80% of the time feeding on horizontal slopes. The median feeding angles ranged from 35° to 90°. There are four significantly different groups of feeding angles among the eight rock-dwelling species that were examined: (1) L. trewavasae (35°), (2) L. fulleborni, M. auratus, and P. elongatus (44.8–48.5°), (3) T. tropheops (58.4°), and (4) Petrotilapia spp., T. gracilior, and M. zebra (84.2–90.2°). Feeding angles within a species did not vary with location or differences in fish community structure. Feeding angles were associated with a combination of mouth position and head shape. We hypothesized that feeding angles may be important in differential access to food.

I describe morphological and ecological characteristics including habitat use, diet, and male and female reproductive cycles of Mabuya longicaudata, an oviparous lizard inhabiting a tropical island off the coast of Taiwan. Nearly 50% (n  =  76) of individuals observed were in holes in a concrete wall that had higher temperatures than other microhabitats. The diet consisted mostly of orthopterans (31.1%), coleopterans (20.5%), and hemipterans (15.2%). Four prey categories, Tettigoniidae, crickets, Scarabaeidae, and Cicadellidae, dominated the diet, and some lizards' stomachs contained plant food, including seeds, leaves, and fruit. The mean snout-vent length (SVL) of adult males (n  =  71) was 118.7 mm (range 100.9–130.4), and that of females (n  =  82) was 113.5 mm (range 98.1–126.8). Females exhibited a spring vitellogenic period with parturition occurring from February to August. The onset of vitellogenesis showed a negative correlation with the mass of the female fat bodies. Females produced one to 13 eggs per clutch, and clutch size was positively correlated with SVL. Two clutches were suggested during a single year in some individuals. Testis mass showed cyclical changes with a maximum in the breeding months from January to July. Male fat bodies exhibited the lowest mass from January to June, coincident with the period of reproductive activity. Clutch size in other Mabuya species are compared with those in M. longicaudata.

The evolution of exaggerated structures that function as weapons in sexually dimorphic species is often explained by intra-sexual selection related to male combat, as these structures are used in fights among males and can determine dominance during such interactions. In many lizard species, males have a larger head than females, a condition attributed to intra-sexual selection. Although head size has been shown to predict dominance in lizards, the way that head size influences dominance remains unclear. We staged interactions between body size-matched male Venerable Collared Lizards (Crotaphytus antiquus) in the laboratory to test the hypothesis that harder-biting males would be dominant over males with weaker bite-force performance. Winners of staged interactions bit significantly harder than losers, but no measured morphological trait was significantly different between winners and losers. This result indicates the strong role of weapon performance, as opposed to weapon morphology, in determining dominance.