The Niangua darter, Etheostoma nianguae, is a threatened stream fish endemic to the Osage River basin in south-central Missouri. We studied the darter's distributional patterns at three spatial scales (stream, reach, and microhabitat) to assist ongoing conservation efforts. Darter presence-absence as a function of one or more habitat variables was modeled with logistic regression at each scale. The most important predictors of presence-absence were stream link magnitude, mean confluence difference (CD), reach length or gradient, streambed elevation, bank erosion index, water depth, and substrate mean particle size. At the stream scale, darters were present in larger streams (e.g., fifth order) with small CDs. A relatively small CD, for example, described the convergence of two streams of roughly equal size in the drainage basin, whereas a relatively large CD indicated a substantial difference at a confluence. We propose that the CD metric represents a large-scale zoogeographic barrier to E. nianguae, excluding this species from any tributary stream that flows into a receiving stream that is three or more stream orders larger than the tributary. Within one occupied stream, the Little Niangua River, darters were found disproportionately in reaches (1) located in the mid- to lower sections of the stream (elevations 230–250 m above sea level), (2) with riffles spaced 40–80 m apart or with gradients of 2–4 m × km⁻¹, and (3) with relatively uneroded banks. Within occupied reaches, they were commonly located in microhabitats 20–40 cm deep with substrate particles averaging 30–50 mm in diameter. Multivariate model precision ranged from 29–57% within single scales. The models can be used to guide conservation and recovery efforts by ranking sites in the Osage basin based on their relative suitability for E. nianguae.

Evolutionary relationships among large-bodied species in the gekkonid genus Pachydactylus were investigated using mtDNA sequences from the cytochrome b and 16S ribosomal RNA genes. We combined these data in parsimony and maximum likelihood analyses to address several systematic issues regarding the eight large-bodied taxa, including their phylogenetic position in Pachydactylus as a whole. The large-bodied Pachydactylus do not form a monophyletic group; rather, large size appears to be plesiomorphic. Neither do the large-bodied species exhibiting regional integumentary loss constitute a natural group, as this unusual predator escape mechanism appears in two disparate clades. Both the namaquensis and bibronii groups are monophyletic, the latter being strongly supported. Pachydactylus tuberculosus and Pachydactylus tetensis are consistently basal across analyses, although their phylogenetic position relative to the sister taxon Rhoptropus is uncertain. Equally weighted parsimony recovered a weakly supported Pachydactylus sensu lato (i.e., Pachydactylus tuberculosus and tetensis), whereas weighted parsimony and maximum likelihood analyses depict tetensis and tuberculosus as taxa sister to Pachydactylus Rhoptropus. Concordance across all analytical methods lends validity to the synonyms Homodactylus Gray and Elasmodactylus Boulenger, which could be resurrected without compromising the monophyly of the remaining Pachydactylus.

Patterns of morphological and behavioral transition during the early ontogeny of windowpane, Scophthalmus aquosus, were quantified to examine the sizes (total length, TL) at which ontogenetic events took place. One of seven categorical transitions (i.e., flexion) and eight of 15 meristic and morphometric transitions (e.g., fin ray and pterygiophore development) occurred between 5 and 10 mm TL. Over 50% of the morphological characters examined were at intermediate stages of development when windowpane were between 10 and 30 mm TL (e.g., eye migration, pelvic fin asymmetry, squamation). The transitional morphology exhibited over this size range coincided with a period of behavioral transition (i.e., pelagic to demersal). By the time windowpane had reached 50 mm TL, morphological transition in all characters was complete and windowpane were capable of burying completely in substrate. Size-independent measures of variability (coefficients of variation, CVs) in character transitions were similar across character types, with the lowest CVs consistently recorded for morphometric transitions (1.73–1.81%). All transitions exhibited minor deviations from the fitted response curves (meristics, behaviors, morphometrics: r² = 0.78–0.99 (range), P < 0.0001; morphological stages: χ² = 4.8–25.5 (range), P < 0.05). By providing an objective framework for modeling ontogenetic progression, this study facilitates the prediction of the ontogenetic state of an individual knowing only its size and provides suggestions for establishing causal relationships between morphological, behavioral and ecological transitions in this and other species.

Growth rates recorded between 1995 and 2001 for green turtles in the central Gulf of California were analyzed using nonparametric regression modeling. A mixed longitudinal sampling design provided 21 growth rate estimates from 19 turtles recaptured at intervals ≥ 11 months. Initial straight carapace length (SCL) of turtles ranged from 58.6–93.8 cm. Growth rates ranged from 0.2 cm/yr to 3.4 cm/yr. The size-specific growth rate function was nonmonotonic, rising steadily from slightly under 1.0 cm/yr in the smallest sizes (approximately 60 cm SCL) to a maximum growth rate of 1.5 cm/yr at about 85 cm SCL, then declining to just over 1 cm/yr for turtles > 90 cm SCL. Mean annual growth was 1.4 cm/yr. We estimate turtles require 9–21 yr in this neritic habitat to attain maturity. These data represent the first information on wild green turtle growth in temperate regions of the Eastern Pacific Ocean.

We used complete sequence of the mitochondrial cytochrome b gene to test monophyly of the Sparoidea, Sparidae, six subfamilies of Sparidae, and to elucidate the interrelationships of the 33 recognized sparid genera. The analysis included 40 sparid species, 10 closely related species, 10 basal percoids, and two nonperciform outgroup species. The aligned 1140 base pairs of cytochrome b yielded 542 parsimony informative characters. Mutational analysis revealed that third codon position transitions were saturated and, therefore, of questionable use in phylogenetic analysis. However, the third codon position transversions and all first and second codon substitutions were not saturated and thus judged more reliable for inferring evolutionary relationship. Parsimony analysis of the equally weighted nucleotide data, weighted nucleotide data set (saturated position transitions given a weight of zero) supported a monophyletic Sparidae with the inclusion of Spicara, which is traditionally included in Centracanthidae. The previously proposed composition of genera within the six sparid subfamilies (Boopsinae, Denticinae, Diplodinae, Pagellinae, Pagrinae, and Sparinae) were not monophyletic in all analyses. This suggests the feeding types on which the subfamilies are based were independently derived multiple times within sparid fishes. In all analyses, Lethrinidae were sister to Sparidae. Sparoidea (Sparidae, Centracanthidae, Lethrinidae, and Nemipteridae) were monophyletic only in the weighted nucleotide phylogeny.

We describe a new species of crocodile (Reptilia: Crocodyloidea: Mekosuchinae) from a maxilla recovered at the Arapus archaeological site, on the island of Efate, Vanuatu, South Pacific. As with mekosuchine species in New Caledonia and Fiji, Mekosuchus kalpokasi sp. nov. was a small, possibly terrestrial carnivore that is now extinct. The differences between the Efate specimen and previously described species of Mekosuchus warrant recognition of a new species. Based on its association with Efate's earliest known human inhabitants, dating approximately 3000 cal yr B.P., the extinction of M. kalpokasi and other insular mekosuchines may have been anthropogenic. The lack of adequately dated pre-Quaternary and Quaternary vertebrate fossil records from Vanuatu, New Caledonia, and Fiji (as well as other smaller islands) precludes determining the timing and route of dispersal of mekosuchine crocodyloids.

Phylogenetic analyses based on nucleotide sequence data of the 12S and 16S mitochondrial ribosomal genes were performed for representatives of the Pleuronectiformes (flatfishes). Two parsimony analyses with percomorphs and basal acanthopterygians designated as outgroups were conducted; equal weighting of all nucleotides and loop regions analyzed for transversions only. A bayesian analysis was performed under the likelihood model TrN I Γ. A monophyletic Pleuronectiformes was resolved in all analyses. Results are consistent with the current higher level classification, recognizing the suborders Psettodoidei and Pleuronectoidei. Psettodoidei consists of a single family, Psettodidae, that is sister to all other flatfishes. Within the Pleuronectoidei three clades are identified. Bothids plus paralichthyids (in part) form a clade in all analyses. A solelike clade containing citharids, cynoglossids, samarids, soleids, Trinectes (Achiridae), and Poecilopsetta (Poecilsopsettidae), is identified in the parsimony analyses. However, a solelike clade was not recovered in the bayesian analysis. A flounderlike clade is identified containing Pleuronectidae and Paralichthyidae (in part) in all analyses. The position of Scophthalmus (Scophthalmidae) differed among all analyses. The results further support the conclusion that eye position is not a useful source of information for the classification of flatfishes. This study provides a new framework for future studies.

We collected data on nesting ecology and identified individual turtles that nested at Parque Nacional Las Baulas, Costa Rica, one of the few remaining nesting sites for Pacific leatherbacks, from 1988–1989 to 1999–2000. We tagged individual female turtles with flipper tags and later with Passive Integrated Transponder (PIT) tags that permitted permanent identification. During the full calendars years of 1990 and 1995, over 93% of nests were laid between the beginning of October and the end of February. We found that 92.4 ± 1% of nesting attempts resulted in successful oviposition, with a mean clutch size of 64.7 ± 1.4 yolked and 38.5 ± 1.0 yolkless eggs (n = 1389). Mean standard curved carapace length and curved carapace width during the surveyed years ranged from 144.4 ± 0.6 cm to 147.6 ± 0.3 cm and from 103.9 ± 0.3 cm to 105.5 ± 0.6 cm, respectively. Reproductive output as determined by estimated clutch frequency (ECF) ranged from 4.3 ± 0.2 to 7.9 ± 0.3 clutches per female per nesting season. The mean period between nesting seasons for an individual turtle was 3.7 ± 0.2 years; only 15% of turtles tagged in 1993/1994 returned to nest again within six years. The nesting population declined from 1367 adult females in 1988/1989 to 231 in 1999/2000. The decline in the nesting population was apparently because of the low incidence of turtles returning to nest in more than one season.

Sequences of cytochrome b (cytb) were used to examine composition and phylogenetic relationships of cyprinid fishes of the tribe Plagopterini, endemic to the Great Basin and Lower Colorado River in southwestern North America. The plagopterin genera, Lepidomeda, Meda, Plagopterus, and Snyderichthys, were most closely affiliated with the chubs Couesius and Margariscus of northern and eastern North America. As indicated by previous morphologic, allozymic, and mtDNA studies, Snyderichthys is intimately related to Lepidomeda. The relationship is paraphyletic, however, according to our molecular data. Snyderichthys from the Snake and Bear River drainages are part of a clade that includes Lepidomeda mollispinis and Lepidomeda albivallis according to the cytb sequence, with Snyderichthys from the central and southern Bonneville basin more divergent. This paraphyly and the complex geographic relationships of mtDNA sequences indicate a complex history of the group and cast doubt on the validity of morphologically diagnosed Snyderichthys. Estimates of divergence time, based on a combination of fossil and molecular data, indicate that the plagopterins are an ancient clade, at least 17 million years old.

Communication by acoustic signals has been extensively studied in anuran amphibians, but other sensory modalities have been largely ignored. We show here that the frog Leiopelma hamiltoni communicates through fecal chemosignals. When given a choice between their own and other individuals' feces, subjects spent more time near their own feces. Further, this effect was greatest when the conspecific was larger in body size, suggesting that information about size as well as individuality is communicated. Time spent near conspecific feces correlated negatively with the distance between the collection sites of the frogs. This correlation may reflect differential responses to the feces of frogs of varied levels of kinship and social familiarity: frogs may avoid nonrelatives and unfamiliar conspecifics. To test the hypothesis that frogs alter fecal production upon exposure to conspecific feces, we presented subjects with either one smear of their own and one smear of a conspecific's feces or two smears of their own feces. Frogs did not defecate more when exposed to conspecific feces. However, when the frogs did defecate, they placed their feces closer to the conspecific's feces than to their own. This supports our hypothesis that feces serve as signals to conspecifics. Visual and tactile cues were eliminated in our experiments. Our results show that the frog L. hamiltoni communicates with conspecifics through chemical signals. We suggest that chemical signaling may be widespread in anuran amphibians.

Three new species of Cyprinodon (Teleostei, Cyprinodontidae) are described, each long recognized as distinct. Cyprinodon pisteri occupies a variety of systems and habitats in the Lago de Guzmán complex basin in northern Chihuahua, México. It is distinguished by its dusky to black dorsal fin and narrow or inconspicuous terminal bar on the caudal fin in mature males. Cyprinodon albivelis is distributed largely in relatively high elevation sites in the upper Río Papígochic (Río Yaqui basin), with a single occurrence in the Río Santa María basin. It is distinguished most notably by the striking white dorsal and anal fins displayed by breeding males. Cyprinodon arcuatus is a distinctive form most similar to Cyprinodon macularius and Cyprinodon eremus and is restricted to the upper Santa Cruz River basin in southern Arizona and Northern Sonora. It is distinguished in having a sharply convex dorsal body profile form the head to dorsal fin origin and in lacking yellow or orange pigmentation on the part of nuptial males. Extensive and careless human alterations to this system drove C. arcuatus to extinction, with the last natural population perishing in Monkey Spring (Santa Cruz County, Arizona), devoured by introduced sport fish. Where appropriate, biogeography and conservation issues are discussed with regard to these species.

When turtle eggs are incubated on media at different water contents, both the water potential and thermal conductivity of the medium change. Snapping turtle eggs were incubated fully buried in sand at constant water content (θ, 4% by mass) but different water potentials (ψ) to assess the effect of ψ on egg water exchange independent of medium thermal conductivity (k). Treatment ψs were fixed using an isopiestic technique. Over the course of incubation, change in fractional egg mass was positively correlated with Ψ. Total egg water exchange ranged from 0.0 to 0.5 g × g⁻¹ of initial egg mass for viable eggs. Hatching success averaged 0.94 for the four highest Ψs but decreased for the two lowest Ψs. Hatchling and yolk mass were independent of water exchange above egg mass gains of 0.1 g × g⁻¹ (Ψs ≥ −542 kPa) but decreased for egg mass gains less than 0.1 g × g⁻¹ (Ψs < −542 kPa). Hatchling and yolk water content and incubation period were independent of egg water exchange for all treatments. The results are consistent with the hypothesis that the thermal conductivity of the incubation medium influences the water exchange of eggs.

Palatogobius grandoculus is described based on two specimens taken from a depth of 256–276 m off Cozumel, Mexico, in the Western Caribbean. It differs from the only other described species in the genus, Palatogobius paradoxus, by having a much larger eye, shorter snout, and narrower interorbital width. Body scales extend forward on sides past the first dorsal fin origin, whereas in P. paradoxus they extend forward only to beneath the soft dorsal fin. Palatogobius grandoculus has 21 pectoral fin rays, whereas there are 18–20 (usually 19) in P. paradoxus. Vomerine teeth are absent in P. grandoculus.

The appendicular skeletal elements in 32 species from all 23 extant genera of amphisbaenians were surveyed via the preparation and study of radiographs, dry skeletons, and cleared-and-stained specimens. Here I report on the presence or absence of those elements, describe their morphology, and make comparisons to several other limbless or limb-reduced squamate taxa that have previously been suggested as close relatives to amphisbaenians. Variability found here in the appendicular skeleton provides a new source of character data for ongoing phylogenetic studies of the group. Comparisons of these elements to those found in potential squamate sister groups indicate that some amphisbaenians share plesiomorphic similarities with limbed squamates such as gymnophthalmid lizards, whereas others share only absence or reduction features with other limbless or limb-reduced squamates, such as dibamid lizards and snakes. This pattern is considered potentially inconsistent with previously proposed hypotheses of amphisbaenian sister groups within squamates. For the pectoral girdle, every stage of reduction—including complete loss—occurs among lizards, amphisbaenians, and snakes. However, the pelvic girdle is never completely lost in lizards or amphisbaenians regardless of the degree of limb reduction or loss; all these taxa retain at least the ilium, and this is also true of most basal snakes. These pelvic girdle elements are variously modified among these taxa, a fact that, together with their widespread persistence, suggests both different patterns of reduction among higher taxa and possible new functional roles beyond the primitive one of supporting the hind limb.

Trichomycterus belensis, new species, is described from a tributary to Laguna Blanca, a high-elevation drainage in the Departamento Belén, Provincia de Catamarca, Argentina. The new species is distinguished from other members of the apparently nonmonophyletic genus Trichomycterus by a combination of features involving the premaxilla, dentition, barbel form, pigmentation, and morphometrics. Trichomycterus alterus, whose original description was based on a limited number of specimens, is redescribed based on numerous specimens from localities in the central and northwestern portions of Argentina.

Interspecific differences in sensitivity to ultraviolet-B radiation (UV-B; 280–315 nm) are well documented for amphibians. However, few studies have addressed physiological mechanisms underlying differential species survival to such exposure. One potential mechanism that might protect amphibians from damaging UV-B involves melanin production and resultant skin darkening. In this study, we examined (1) the darkening response in salamander larvae exposed to UV-B and (2) whether darker larvae have a higher survival rate than lighter larvae when exposed to UV-B. After five days of relatively low UV-B exposure in the laboratory, larval roughskin newts, Taricha granulosa, and Northwestern salamanders, Ambystoma gracile, showed a significant darkening of the skin, as compared to controls exposed to full-spectrum lighting without UV-B. In addition, long-toed salamanders, Ambystoma macrodactylum, showed the same trend for darkening, although it was not statistically significant. To investigate whether survival might be higher for darker larvae exposed to UV-B, we manipulated the skin color of A. gracile and A. macrodactylum larvae by placing them on black or white backgrounds during UV-B exposure. Larvae exposed to UV-B were smaller after three weeks, regardless of background coloration. Background coloration effectively controlled skin color, with larvae on white backgrounds consistently lighter than larvae on black backgrounds. No survival differences were observed between treatments; thus, it remains unclear whether skin darkening provides protection from UV-B damage.

For more than 60 years, the mesopelagic liparid genus Psednos was known from the holotype and paratype of a single species collected off South Africa and described in 1927. Over the last decade, examination of material from collections around the world has revealed specimens from all oceans except the South Atlantic. In this paper, we describe 10 more species of the genus from the north Atlantic and north and south Pacific Oceans. In addition, we partially describe, but do not name, three previously unknown species of which we have specimens in very poor condition and provide a provisional key to all known species. The new taxa bring the number of known Psednos species to more than 25.

Spermatogenesis in Apalone ferox from Palm Beach County, Florida, is found to follow a postnuptial or dissociated pattern. Reduction of epididymis mass and clearing of sperm from the epididymides suggest spring mating. Histology of the testes, somatic index, and tubule diameter all suggest fall spermatogenesis. Males as small as 15.2 cm PL were found to be mature, and all males were reproductive in a given year. The distribution of postnuptial spermatogenesis is mapped on a phylogeny of turtles and suggests that this pattern has evolved at least six times among living turtles.

Karsten, a new genus of amblyopine goby, is distinguished from all other members of the subfamily in having a spinous dorsal fin pterygiophore formula of 3–123, 3–132, or 3–1221 2. The genus is also distinct within the subfamily in having only nine precaudal vertebrae. Karsten lacks eyes as does Amblyotrypauchen, the only other amblyopine genus that is found at depths of 30 m or greater. Karsten has only been collected from Indonesia, the Philippines, and Fiji. Because of its lack of an interneural gap, Karsten is assigned to the “Trypauchen” group; it is compared to other members of this group.

A new two-pored Amphisbaena is described from Formosa and Corrientes provinces of Argentina. The new species has a faint autotomy annulus (with a fracture plane) and two cicatricial precloacal pores separated medially by a pair of nonpored segments. It differs from Amphisbaena dubia, which has a pair of pores on adjacent segments and a fracture plane on the tail, and from Amphisbaena darwini heterozonata, which differs in pore number, coloration, and shape of the autotomy annulus.

We present evidence that a shallow water Indo-Pacific snake eel, occasionally seen and photographed but not recognized by divers, is Ophichthus altipennis (Kaup, 1856) and propose that Ophichthys melanochir Bleeker, 1865 is its junior synonym. Its variable coloration is described and illustrated.

Based on museum specimens, field records, and morphological, acoustical, and geographical analyses, we resurrect the species status of Kassina arboricola Perret, 1985 and redefine Kassina cochranae (Loveridge, 1941). Additionally, we describe Kassina schioetzi sp. nov., a hitherto overlooked species. This species differs from K. cochranae and K. arboricola in several morphological features, especially the shape of the male gular flap, and its very short, tonal advertisement call. All three species are associated with forest habitats. Kassina schioetzi lives in wooded parts of the Guinea savanna of Ivory Coast and a single mountainous locality in eastern Guinea. Kassina cochranae occurs from western Ivory Coast to eastern Sierra Leone; K. arboricola occurs from Ghana to western Ivory Coast. At two localities, K. schioetzi occurs in syntopy with K. arboricola, and at another locality with K. cochranae. A key to all West African Kassina species is provided.

Young-of-year (YOY) northern kingfish, Menticirrhus saxatilis (family: Sciaenidae), were sampled and tagged on ocean and estuarine beaches in southern New Jersey to determine patterns of habitat use, movements, and growth rates for this infrequently studied life-history stage. Beach seines were used to sample YOY biweekly during May–October 1999 at eight ocean, one inlet, and two estuarine beach sites, which resulted in capture of 2172 individuals. Recently settled YOY were first collected at lengths of 7–12 mm standard length (SL) on 7 July in the Great Bay estuary, at 18–32 mm SL on 21 July near the inlet and at 10–34 mm SL on 22–23 July at six of the ocean sites on Long Beach Island. Small fish (< 30 mm SL) continued to be collected in all areas through early September suggesting protracted spawning. Overall, catch per unit effort was greatest at the inlet site during August. A portion of the fish was tagged with internal sequential coded wire microtags on nine dates at one location in the estuary (n = 260 fish, 32–162 mm SL) and less regularly at three sites (n = 519 fish, 34–194 mm SL) on ocean beaches. None of the fish tagged on ocean beaches were recaptured, however, 14% of the fish tagged in the estuary were recaptured from 3–22 days after tagging. Recaptured fish grew quickly (0.7–2.8 mm/day, average 1.8 mm/day) and these growth rates corresponded well with growth rates calculated from regressions of the increase in maximum length over time using length frequency data. The fast growth rates accounted for the fact that by late September or October, when most fish had left the study sites, the largest remaining fish had reached 200–225 mm SL. The abundance and rapid growth rates of young-of-year northern kingfish on ocean and estuarine beaches suggest that both types of habitats can be important for this species.

We investigated differences in metabolism and metabolic substrates between male and female small-mouthed salamanders (Ambystoma texanum) collected from breeding sites. Resting O₂ consumption rates (VO₂) of gravid females at 15 C were roughly double those of males and postgravid females. Whole-body triglyceride and glycogen contents were similar among males, gravid females, and postgravid females, but free glucose contents were higher in both gravid and postgravid females than in males. Respiratory quotients for all groups were ∼0.9, suggesting a relatively high dependence on carbohydrates to fuel metabolism. Our findings suggest that females have a considerably higher metabolic cost of reproduction than do males. Such differences may be associated with aspects of life history and ecology such as sexual size dimorphism, age of sexual maturity, asynchronous arrival at breeding areas, and differential survival between the sexes.

Etheostoma caeruleum were sampled from the James River, southwest Missouri, during eight months, July 1996 through May 1997. Ages were estimated from whole and sectioned otoliths (sagittae) and from scales by counting annuli. Edge analysis indicated that otolith annuli (opaque zones), visible in whole and cross-sectioned otoliths, formed yearly, primarily during July through September. In contrast, scale edge analysis indicated no clear pattern of annulus formation. Independent readers agreed on 63–73% of ages using otoliths but only 38% of ages using scales. Sectioned and whole otolith age estimates made by one experienced reader agreed for 68% of individuals. Scales underestimated age compared to otoliths, and maximum otolith age was five years.

Italian wall lizards (Podarcis sicula campestris) were introduced to Long Island, New York, in 1967 and have subsequently spread through many urban and suburban communities. Their ability to spread further may be limited by their ability to tolerate the relatively cold winters of New York. We found that these lizards were able to survive cold temperatures by supercooling if they were kept dry. However, if freezing was initiated as would be expected under shallow hibernation conditions, these lizards froze and died rapidly. We speculate that Podarcis sicula must hibernate below soil freezing depth, estimated at greater than 24 cm deep, to survive.

Few quantitative data are available on the ways in which venomous snakes respond to humans. We took advantage of extraordinarily high numbers of endemic pit vipers on the small island of Shedao in northeastern China, to quantify snake responses. We approached free-ranging pit vipers in their ambush sites (either in trees or on the ground) and recorded their behavior. The snakes' responses to our approach depended upon (1) the intensity of the stimulus; (2) attributes of the snake (size class, body temperature, whether it had fed recently); and (3) the snake's location (in an arboreal or terrestrial site). Most snakes tolerated close approach. Juvenile pit vipers struck more often than adults, and warmer snakes were more likely to flee, display, or strike rather than rely on crypsis. Snakes on the ground were more likely to flee or strike than were those in trees. Many of the same patterns were seen in our laboratory trials. For example, striking was more frequent in juveniles than adults, in hotter snakes, and in snakes that displayed (tail-vibrated). Both strike speeds and tail-vibration rates increased with body temperature. Responses of Shedao pit vipers to human approach differ from those reported for other snake species.

The Red Hills salamander (Phaeognathus hubrichti), a large fossorial plethodontid endemic to south-central Alabama, was listed as federally threatened in 1976. To determine the seasonal and daily activity patterns of this species, I counted the number of salamanders present at burrow entrances, recorded the amount of time individual salamanders spent at entrances, and measured five abiotic variables to determine how they correlated with the number of salamanders at burrow entrances. Red Hills salamanders were present at burrow entrances all months of the year, displayed a unimodal daily activity pattern, and spent a mean of 12.3 continuous hours at an entrance each day. Regardless of season, time spent at an entrance remained relatively constant. Air temperature had the highest correlation with the number of salamanders present at entrances. Burrow entrances play a prominent role in the lives of these salamanders. When estimating population size for conservation efforts, surveys should be conducted at night and at multiple times and dates during the warmer months of the year because not all salamanders are present at entrances at any one time.

We compared litter size (and its relationship with female SVL), minimum size of females at sexual maturity, and minimum adult size of females, among different populations [from eight coastal sea level and two midelevation (600–800 m) sites] of the live-bearing skink Mabuya agilis in the southeastern Brazilian states of Espírito Santo and Rio de Janeiro. There were no apparent differences in litter size among populations within either lowland or highland groups, but each group differed significantly from the other: highland females had larger litters (mean = 5.6, range 2–9) than those from lowland sites (mean = 3.3, range 1–6). There was a significant positive relationship between litter size and female SVL for each group, but the slope of the regression differed between lowland and highland females, with the latter tending to have larger litters for a given SVL. Highland females also reach larger body sizes, although their minimum size at sexual maturity and minimum adult size are just slightly greater than those from lowland populations. We interpret such intraspecific variation relative to possible effects of the physical environment and of genetic factors on reproduction.

We conducted a laboratory experiment to determine the influence of familiarity on the aggressive behavior of female red-backed salamanders (Plethodon cinereus) from Virginia. Females that were familiar with each other (i.e., had resided together for five days) spent significantly less time in threat displays toward each other than did females that had not previously encountered each other. These plus previously published data suggest that familiarity among individuals plays a role in social interactions of red-backed salamanders at our research site, where encounters among individuals must be frequent because of a high population density. Reduced aggression with familiarity implies that these salamanders remembered past associations, which would conform to assumptions of the “dear enemy” phenomenon, the “war of attrition” model, and the “fight to learn” hypothesis.

We studied the periodicity of formation of growth marks in the bones of the tropical frog Rana cyanophlyctis. Frogs were maintained in the laboratory for one year under natural temperature and day length. Toe clippings were made at the beginning and at the termination of the experiment. Skeletochronological comparison of initially clipped toes with those clipped at the termination of the experiment revealed that in all the frogs an additional growth mark or line of arrested growth (LAG) appeared in the phalangeal histology, suggesting that the formation of growth marks is annual in this tropical frog.