The enigmatic biogeography of Pacific island boas of the genus Candoia is examined using DNA sequence variation from a portion of the mitochondrial cytochrome b gene. Estimates of the phylogenetic relationships and genetic distances between Candoia and the Old World (Sanzinia) and New World boids (Boa, Corallus, and Epicrates) suggest that a recent dispersal event from the Americas is not responsible for Candoia's Papuan distribution. Multiple populations from the three Candoia species are sampled to distinguish whether substantial evolutionary partitions exist within species as a result of colonization patterns or geographical barriers and to assess whether genetic partitions are concordant with species boundaries. In all analyses, Candoia and the Madagascan Sanzinia are sister taxa, and C. bibroni is basal to C. aspera and C. carinata. Mean sequence divergences between Candoia and the other boid genera Sanzinia, Corallus, Epicrates, and Boa are 0.19, 0.23, 0.24, and 0.25, respectively. Within Candoia, mean interspecific sequence divergence ranges from 0.13, between C. aspera and C. bibroni, to 0.16 for both C. aspera/C. carinata and C. bibroni/C. carinata pairwise comparisons. Large intraspecific sequence divergence (up to 0.13 within C. carinata) exists within Candoia species demonstrating deep separations corresponding to patterns of island colonization and geographic barriers in New Guinea.

Variation in mitochondrial DNA (mtDNA) was assessed in a captive stock and 11 wild populations (n = 259) from throughout the native range of Desert Pupfish Cyprinodon macularius as traditionally understood. Using PCR-SSCP, 18 composite haplotypes were identified from a 333-bp segment of the mitochondrial D-loop and two segments of the ND2 gene (333 and 325 bp). Representatives of each haplotype were sequenced for the entire ND2 gene and the 337-bp segment of the D-loop. Phylogenetic analyses revealed that haplotypes form two monophyletic groups, one in the Río Sonoyta/Quitobaquito Springs area and one in the Salton Sea/Colorado River Delta. This, with previous observations on morphology, color pattern, and geological history, supports recognition of the Río Sonoyta/Quitobaquito populations as a separate species, the Quitobaquito Pupfish C. eremus Miller and Fuiman, from the more widespread desert pupfish C. macularius Baird and Girard. More than 70% of mtDNA diversity across all populations was attributable to differences between the two species. Within species, the average local population contains 94% and 97% of the diversity in, respectively, C. eremus and C. macularius. Differences between the Salton Sea and Colorado River Delta populations of C. macularius explain a small (3.7%), but statistically significant, portion of mtDNA diversity in this species. This and the history of connections between Salton Sea and the delta suggest that the two regions should be managed separately with no intermixing of pupfish other than what occurs when the present, human-regulated hydrology is overcome by natural flooding. Haplotype frequencies in C. eremus from Quitobaquito Springs and Río Sonoyta were not significantly different. However, the potentially long history of isolation between these two populations and evidence of some degree of morphological divergence indicate a need for conservative management with no intermixing. The captive stock exhibited reduced mtDNA variation relative to its wild parent population from a locality on the delta.

Variación de ADNmt fue examinado por una cepa de cautivo y 11 poblaciones silvestres (n = 259) de todas partes del rango natural del cachorrito del desierto Cyprinodon macularius como entendido tradicionalmente. Utilizando PCR-SSCP, 18 haplotipos compuestos fueron identificados desde un segmento de 337-pb del D-loop mitocondrial y dos segmentos del gene DN2 (333 pb y 325 pb). Representantes de cada haplotipo fueron sequenciados por el gene DN2 entero y el segmento de 337-pb del D-loop. Análisis filogenético mostró una relación monofilética reciproca entre poblaciones de dos regiones generales, Río Sonoyta/Quitobaquito y Salton Sea/Delta del Río Colorado. Esto, con observaciones previas de morfología, patrón de color, y la história geológica, sostiene el reconocimiento de las poblaciones de Río Sonoyta/Quitobaquito como una especie distinta, el cachorrito de Quitobaquito C. eremus Miller and Fuiman, de la especie con una distribución más amplia, el cachorrito del desierto C. macularius Baird and Girard. Más de 70% de la diversidad ADNmt de todas las poblaciones fue atribuida a diferencias entre las dos especies. Dentro de cada especie, la población promedia local contiene 94% y 97% de la diversidad de, respectivamente, C. eremus y C. macularius. Las diferencias entre las poblaciones de C. macularius del Salton Sea y las de la Delta del Río Colorado explican una pequeña (3.7%) pero una porción estadísticamente significativa de la diversidad ADNmt de esta especie. Esto y la historia de conecciones entre el Salton Sea y la delta sugieren que los dos regiones deben ser manejadas aparte sin mezclar a los cachorritos más que lo que ya ocurre cuando la hidrología actual controlada por los humanos, está conquistada por inundaciones naturales. Frequencias de los haplotip

In December 1991, we initiated a long-term study of the California Tiger Salamander (Ambystoma californiense) at a breeding pond in Monterey County, California. Because of habitat loss, this species is a candidate for federal endangered species status, but many basic features of its life history and demography have not been studied in detail. During the first seven years of this study, we captured, measured, individually marked, and released 657 breeding adults and 1895 newly metamorphosed juveniles at the drift fence encircling this pond. We also used skeletochronology to investigate age structure in cohorts of breeding adults. Numbers of breeding adults varied by more than a factor of four among years, and annual juvenile production ranged from 121–775 metamorphs. Contrary to the results of related studies, total juvenile production was positively related to the total biomass of breeding females. Both skeletochronology and mark-recapture data indicate that most individuals do not reach sexual maturity until 4–5 years of age, and, although individual longevity can exceed 10 years, less than 50% of individuals returned to breed a second time. These results suggest that this breeding population was a reproductive sink during the period of this study and that isolated breeding ponds may be insufficient for the long-term maintenance of viable populations of A. californiense.

A recent morphological analysis demonstrated that Cyclothone, one of four currently recognized gonostomatid genera, was nested within Gonostoma, rendering the latter paraphyletic. In an attempt to resolve the interrelationships of Gonostoma and Cyclothone using molecular data, we determined the nucleotide sequences of a portion of the mitochondrially encoded 12S and 16S ribosomal RNA genes from 11 gonostomatids, including all seven valid Gonostoma species, and Diplophos taenia as an outgroup. Secondary structure-based alignment resulted in a character matrix consisting of 566 base pairs of unambiguously aligned sequences from the two genes, which were subjected to phylogenetic analyses using maximum-parsimony and maximum-likelihood methods. The resultant tree topologies from the two methods were congruent, with many nodes being strongly supported by various tree statistics. As in the morphological analysis, the molecular data indicated the monophyly of Gonostoma Cyclothone and paraphyly of Gonostoma, although the intrarelationships of Gonostoma differed greatly from those suggested by the morphological data. The molecular data supported the existence of two basal, paraphyletic clades within Gonostoma, the first comprising two light-colored species (G. atlanticum, G. denudatum) and representing a sister clade of Cyclothone, and the second, five dark-colored species (G. ebelingi, G. elongatum, G. longipinnis, G. gracile, G. bathyphilum). Although several alternative classifications exist that reflect the molecular phylogeny, the resurrection of Sigmops Gill, 1883 for the clade of Gonostoma comprising five dark-colored species is proposed to maximize the information content in the classification.

Tadpoles in nature are often found with injured tails. We introduce a planimetric technique for compiling data on the injuries sustained by individual tadpoles, which allows us to visualize and quantify the tail damage sustained by a population as a whole. We have used this technique to compare the pattern and severity of damage in tadpoles from seven species (Ascaphus truei, Bufo americanus, Phyllomedusa tomopterna, Pseudacris crucifer, Rana catesbeiana, Rana sylvatica, and Rhinophrynus dorsalis) that differ in microhabitat use (benthic vs pelagic), tail morphology (filamentous vs nonfilamentous) and palatability to predators. We also examined differences in tail damage across developmental stages. Finally, we compared interpopulation variation for R. sylvatica tadpoles from six separate ponds. The tail tip was the most commonly damaged area in all tadpoles, although the pattern and severity of injury varied greatly across species. Unpalatable, benthic larvae sustained small nicks around the margin of the tail, whereas pelagic and palatable species more often had the tail tip sheared off caudally. Little damage was found in any species in the anterior portion of the tail, where most thrust is generated during swimming. Only one species, A. truei, exhibited increased tail damage as the tadpoles aged. Later stage P. crucifer and R. sylvatica larvae in contrast, had significantly less tail damage than younger stage conspecifics. Although this could be the result of different healing rates at different stages, alternatively it suggests that for these species, survivorship is ultimately reduced in individuals that lose a substantial part of the tail when they are young.

Declines of native big-river fishes of the Colorado River Basin, southwestern United States, have been attributed in part to emplacement of hypolimnial-release dams. Lowered spring-summer tailwater temperatures inhibit spawning and embryonic development, depress swimming performance and growth, and reduce survival of early life stages. We examined effects of three temperatures (10 C, 14 C, 20 C) on aspects of growth, development, and physiology of larval and early juvenile life stages of Xyrauchen texanus (Razorback Sucker), Catostomus latipinnis (Flannelmouth Sucker), Gila cypha (Humpback Chub), and Ptychocheilus lucius (Colorado Squawfish) in the laboratory. Lengths, weights, and specific growth rates of all species were significantly lower at 10 C and 14 C than at 20 C, and time to transformation from larval to juvenile life stage was delayed at colder temperatures. Transfer of fishes from 20 C to 10 C (simulating transport from warm tributaries to cold tailwaters) caused loss of equilibrium in youngest life stages. All these effects increase exposure of larvae to existing sources of mortality. Conservation of the big-river species in hypolimnial-release tailwaters will require thermal modification of dam discharges to lessen detrimental effects of cold water temperatures. Because such action may also benefit nonindigenous biota, recovery of the native fauna may ultimately depend upon implementation of comprehensive (and likely expensive) control measures against nonnative species.

Orientation toward and away from shore (y-axis orientation) plays an important role in the daily and seasonal movements of amphibians. A variety of studies have shown that amphibians use both celestial cues and the geomagnetic field for y-axis orientation. However, few studies have addressed how quickly amphibians are able to learn the direction of a new shore. In the present laboratory-based experiments, we show that the Eastern Red-Spotted Newt, Notophthalmus viridescens, is able to learn the direction of the y-axis with respect to the geomagnetic field within 12–16 h. In conjunction with previous findings, our results suggest that the geomagnetic field is an important and readily used cue for orientation in amphibians.

The phylogenetic systematics of esocoid fishes are examined using comparisons of partial DNA sequences of the mitochondrial genes coding for the transmembrane protein cytochrome b and the 16S RNA ribosomal subunit. Nucleotide sequences from all species of umbrids, three species of esocids, and salmonid, osmerid, cypriniform, and neoteleostean outgroups were compared to determine patterns of molecular evolution and uncover evidence of phylogenetic relationships. Multiple sequence alignments for each of the two DNA regions examined were used to characterize the amount and type of change shown by the data. The sequences were analyzed under different models of molecular evolution using maximum-parsimony and maximum-likelihood optimality criteria of phylogenetic reconstruction. The phylogenetic analyses revealed previously undiscovered affinities between species of umbrids and esocids that imply the paraphyly of the Umbridae as currently defined. The following set of esocoid interrelationships is proposed: (((Esox, Novumbra), Dallia), Umbra). Esocoid classification is revised based on present findings.

Questions concerning the origin of parthenogenesis in Caucasian Rock Lizards and genetic divergence among bisexual lizards of the Lacerta raddei complex were examined using sequences from the mitochondrial cytochrome b gene. The maternal parent of the parthenogenetic L. uzzelli, L. sapphirina, and L. bendimahiensis was confirmed to be L. raddei. Although substantial variation was revealed among bisexual populations of L. raddei and L. nairensis, very low or no variation was found among the parthenogenetic species. A phylogenetic tree including 11 populations of L. raddei and L. nairensis, as well as 10 populations of its five daughter parthenogens, was constructed. Because of paraphyletic relationships, L. nairensis is considered conspecific with L. raddei. Evaluation of the parthenogenetic species suggests that separate hybridization events between L. raddei and L. valentini might have occurred at least twice. One resulted in L. sapphirina and L. bendimahiensis, and the other one (or more) resulted in L. unisexualis and L. uzzelli. The females involved were distantly related, Lacerta unisexualis and L. uzzelli likely had separate origins, but the females involved were closely related.

Allozyme electrophoresis was used to investigate genetic population structure among 245 individuals of the silverside Odontesthes argentinensis sampled from localities in southern Brazil and Uruguay. Striking differences in allozyme frequencies and genetic variability were detected among localities. Analysis of these differences indicated two distinct populations: one distributed in a wide marine coastal zone; and one in the peripheral environment of the Patos Lagoon estuary in southern Brazil. The population in Patos Lagoon appears to have originated from an ancestral marine population and been established in the estuary by a founder effect. The extent and pattern of genetic divergence found in our study, the existence of diverse reproductive strategies in the estuarine silversides, and differences in morphology of eggs and larvae, indicate that speciation is taking place in Patos Lagoon. It is suggested that the two populations should be considered separately when formulating management and conservation strategies.

We examined the functional prediction of covariation between relative hind limb morphology and jumping performance for newly metamorphosed frogs from the hybridogenetic Rana esculenta complex. For the two parental species, R. lessonae and R. ridibunda, and three coexisting hybrid hemiclones (GUT1, GUT2, GUT3), we varied larval densities to test the relationship of morphology to performance at both the intraspecific and interspecific levels. Across all genotypes, frogs raised at low density were larger and jumped farther than those raised at high densities. Size-independent maximum jumping performance was repeatable for all hemiclones and species. Comparisons across densities indicated that covariation between morphology and performance matched the biomechanical prediction except for R. ridibunda. Rana ridibunda frogs raised at low larval density jumped relatively farther than those raised at high larval density but, in spite of differing growth environments, did not show differences in relative length of the hind limb. At the intraspecific level, significant performance gradients for hind limb length were found in the hemiclones GUT1 and GUT3 and in R. ridibunda at low larval density. Relative jumping performance of GUT2 and R. lessonae at low larval density and all genotypes at high larval density were not explained by the partial effect of any morphological trait. At the interspecific-interclonal level the biomechanical prediction was confirmed only at the high larval density. These results reveal a lack of congruence of the morphofunctional relationships both at different larval growth conditions within populations and also at intra- and interpecific levels.

The reproductive characteristics of six geographically isolated populations (n = 1150) of Spotted Sand Bass, Paralabrax maculatofasciatus, from throughout their natural range were studied from April 1992 to July 1994. Histological examination of gonads revealed the following: (1) a membrane-lined cavity or gonadal lumen was present in 9% of all males observed in this study, being present in the San Diego Bay, Los Pulpos, and Guerrero Negro populations; (2) sperm sinuses containing developing sperm were present in 65% of all females in the Anaheim Bay, Newport Bay, San Diego Bay, Los Pulpos, and Magdalena Bay populations; (3) atretic or yellow bodies were present in 76% of all males; and (5) five transitional individuals were found in the Los Pulpos and San Diego Bay populations. Both primary and secondary males were represented in all populations indicating diandric origin of males. Analysis of sex frequencies by age class and by length class for the San Diego and Los Pulpos populations showed a bimodal distribution indicative of protogynous hermaphroditism. Specimens from Anaheim Bay and Newport exhibited patterns more typical of a gonochoric reproductive pattern, whereas the Guerrero Negro and Magdalena Bay populations exhibited intermediate patterns. Only the spotted sand bass populations from San Diego Bay and Los Pulpos exhibited trends typical of protogynous hermaphroditism in both the histological and age/length population structures. Therefore, the reproductive patterns observed in the six populations of spotted sand bass are best represented by a spectrum ranging between gonochorism and protogynous hermaphroditism. The key to this diverse spectrum of strategies may be the ability of females to change sex, to delay sex change to later in life, or not to change sex at all. This reproductive plasticity also allows the females to maximize their reproductive fitness regardless of population size, breeding site densities, and accompanying mating systems.

Cannibalism provides a potential mechanism for enhanced growth and survival for species with complex lifecycles developing in habitats of unpredictable duration. We asked whether background resource quality affected survival and metamorphosis of Cuban Treefrog (Osteopilus septentrionalis) tadpoles fed conspecifics. In a factorial experiment, we crossed two levels of background resources, a high-quality (commercial rabbit chow) or low-quality (algae and periphyton) diet with no conspecifics, the presence of a dead conspecific (in a bag), or ad libitum availability of dead conspecifics. Survival of tadpoles did not differ significantly among treatments. Availability of conspecifics resulted in larger mass and decreased larval periods for tadpoles on low-quality background treatments; however, for tadpoles on high-quality background treatments, availability of conspecifics resulted in prolonged larval periods. These results suggest that profitability of feeding on conspecifics is dependent on background resource level and may partially explain why cannibalism is facultative and associated with low availability of alternative food or crowded conditions in most larval anurans.

The cavity-nesting darters Etheostoma nigripinne, Etheostoma crossopterum, and their hybrid (E. nigripinne × E. crossopterum) were found to produce sounds associated with reproduction. Males produced sounds during aggressive encounters and courtship activities. All three taxa produced nonpulsed sounds categorized as drums and shorter, usually pulsed, sounds categorized as knocks. In addition, E. nigripinne produced pulsed sounds referred to as purrs that differ from knocks in having a higher pulse number and rate. All sound types were made under both aggressive and courtship contexts by males of all three taxa. The dominant frequency and duration of sounds differed by sound type (drums, knocks, purrs) for all taxa. In addition, within the drum sound type, the dominant frequency differed between contexts (aggression vs courtship) and among taxa. Although sound production has been documented for numerous fish species, this is the first time sounds have been described for percids. The mechanism and role of sound production in darters has yet to be determined.

A brief review of the Liophis taeniurus group from western South America is given. Also included are descriptions of two new species (vitti and janaleeae), a taxonomic comparison of taeniurus and festae, and a brief description of variation among them.

Symphurus insularis, a dwarf species of tonguefish reaching sizes to about 80 mm SL, is described based on 39 specimens collected in shallow-water habitats (3–23 m) at Madeira, the Canary Islands, and São Miguel, Azores. The new species is distinguished from its congeners by the combination of a 1-3-2 ID pattern, 12 caudal fin rays, 80–87 dorsal fin rays, 66–72 anal fin rays, 45–48 total vertebrae, 84–98 scales in a longitudinal series, unpigmented peritoneum, and ocular surface pigmentation featuring a yellowish to dark-brown background with a series of 3–8 mostly incomplete crossbands and usually 1–3 small, dark, spherical spots arranged in a longitudinal row along the body midline, together with a series of dark blotches alternating with unpigmented areas on the dorsal and anal fins, and a spot and dark band on the caudal fin base with the distal four-fifths of the caudal fin unpigmented. Symphurus insularis most closely resembles S. reticulatus from St. Helena, S. rhytisma from the Caribbean Sea and northern Brazil, and S. lubbocki from Ascension Island. Symphurus insularis is the only species of dwarf tonguefish known from shallow-water habitats in the Macaronesian biogeographic subprovince of the eastern Atlantic. Previous reports of other species of symphurine tonguefishes from shallow-water habitats in these areas were based on misidentifications. A key to species of Symphurus occurring in middle and eastern Atlantic waters is provided.

A new lizard species of the genus Cnemidophorus (Teiidae) is described from Barra de Maricá, Rio de Janeiro State, southeastern Brazil. The species is characterized by having a narrow pale vertebral stripe, with two irregular narrow stripes [one dorsolateral (sometimes broken) and one lateral] on each side of it, and a sequence of small pale dashes on each side of the dorsal field. Its tail is bright blue-green, in contrast to the brownish tail of C. ocellifer. The new species has higher counts of femoral pores on each side (12–20) than the closely related species C. ocellifer (7–12) and C. nativo (11–13) and differs further from those species in other morphometric and meristic characters, such as the number of subdigital lamellae on fingers and toes and transversal and longitudinal counts of ventral scale rows.

Uma nova espécie de lagarto do gênero Cnemidophorus (Teiidae) é descrita de Barra de Maricá, no Estado do Rio de Janeiro, sudeste do Brasil. A espécie é caracterizada por uma listra vertebral clara e estreita e duas listras irregulares (uma dorsolateral [que pode ser interrompida] e uma lateral) de cada lado da mesma, com uma sequência de pequenos pontos claros de cada lado do campo dorsal. Sua cauda é verde-azulada, contrastando com a cauda marrom de C. ocellifer. A nova espécie possui mais poros femorais de cada lado (12–20) do que as espécies próximas C. ocellifer (7–12) e C. nativo (11–13), e difere destas também em outros caracteres merísticos, como o número de lamelas subdigitais dos dedos e artelhos e as contagens transversais e longitudinais de escamas ventrais.

A new species of Dasyatis is described from the southwestern Atlantic, off northeastern Brazil. It differs from its congeners by its relatively large eyes, presence of well-developed dorsal and ventral finfolds on tail ending approximately on the same vertical line, dorsal and ventral color patterns, and possession of distinct ventral markings on disc. Adults are apparently associated with coral or sandstone reefs.

Uma nova espécie de Dasyatis é descrita do Atlântico ocidental, da costa nordeste do Brasil. Ela difere de suas congêneres pelos olhos relativamente grandes, pela presença de membranas dorsais e ventrais bem desenvolvidas na cauda, terminando aproximadamente na mesma linha vertical, pelo padrão de colorido dorsal e ventral, e por possuir manchas distintas ventrais no disco. Adultos são aparentemente associados a recifes coralinos ou areníticos.

A new species of leptodactylid frog, genus Eleutherodactylus, is described from cloud forest of the northeastern versant of the Bolivian Andes. Eleutherodactylus ashkapara sp. nov. seems to be most closely related to E. pluvicanorus from which it is distinguished mainly by larger size, advertisement call, and arboreal habit. Because of many phenetic similarities, I propose that E. ashkapara, E. fraudator, and E. pluvicanorus be recognized as a species group distinct from other groups of South American Eleutherodactylus.

This paper summarizes information on the South American freshwater gymnotiform genus Sternarchorhynchus Castelnau (family Apteronotidae), especially taxonomic and systematic. Sternarchorhynchus britskii and S. mesensis are described as new from the upper portions of the Rio Paraná and Rio Tocantins (Brazil), respectively. The new species are distinguished from currently recognized species by morphometric and meristic features such as the relative sizes of structures in head, size of pectoral fin, and number of anterior unbranched anal fin rays. The two new species, along with S. curvirostris (Boulenger) and S. roseni Mago-Leccia, are hypothesized to comprise a monophyletic subunit, tentatively recognized herein as the “Sternarchorhynchus curvirostris group,” based on the color pattern of anal and pectoral fins. Species relationships within Sternarchorhynchus are discussed.

Este trabalho resume informações sobre o gênero sul-americano de Gymnotiformes Sternarchorhynchus Castelnau (família Apteronotidae), especialmente taxonômicas e sistemáticas. Sternarchorhynchus britskii e S. mesensis são descritas como novas das porções superiores dos rios Paraná e Tocantins (Brasil), respectivamente. As novas espécies são separadas das demais espécies válidas atualmente incluídas no gênero com base em características morfométricas e merísticas tais como, por exemplo, o tamanho relativo de estruturas na cabeça, nadadeira peitoral e número de raios anteriores indivisos da nadadeira anal. Estas duas novas espécies, juntamente com S. curvirostris (Boulenger) e S. roseni Mago-Leccia, são supostas como compreendendo uma subunidade monofilética reconhecida aqui de maneira tentativa como o “grupo Sternarchorhynchus curvirostris” com base em padrões de coloração das nadadeiras anal e peitoral. Relações entre as espécies de Sternarchorhynchus são discutidas.

We describe a new species of stream-breeding frog of the genus Amolops, Amolops bellulus, from the mountainous region of Lushui County, Yunnan Province, China, near the boundary between Yunnan and Myanmar. This species differs from all its congeners in a combination of morphological characteristics including the absence of a circummarginal groove at the tip of first finger, lack of a supratympanic fold, a white band along the upper jaw extending to shoulder, a black band starting from tip of snout along upper loreal region and extending to anterior flank of body, absence of a vocal sac, tympanum distinct and feebly concave, and the presence of vomerine teeth.

We analyzed mitochondrial DNA variation in the Ringed Salamander, Ambystoma annulatum. Four of six populations studied were fixed for the same haplotype. We attribute this lack of detectable variation to recent colonization of this area, a hypothesis which is supported by paleoecological data and previous biogeographical analysis of the sympatric Spotted Salamander, Ambystoma maculatum. This study demonstrates the potential benefits of comparing biogeographical data across species and suggests that the Hypsithermal Interval may be an overlooked source of important historical impacts for species in the midwestern United States.

The mitochondrial cytochrome b gene was sequenced from Acantholingua ohridana from Lake Ohrid, Macedonia, and Salmo salar; and these sequences were compared to those previously obtained from S. trutta and five other salmonid species. In addition, a nuclear sequence, the first internal transcribed spacer (ITS1) of the ribosomal DNA, was obtained from A. ohridana, S. salar, and S. trutta and compared with sequences obtained from the same five salmonid species. Combination of these data with nuclear GH2C intron sequences for the same taxa yielded a combined dataset of approximately 2100 aligned bp for eight species. Phylogenetic analysis of all datasets supported the inclusion of A. ohridana in Salmo and a sister relationship between A. oridana and S. trutta.

We used satellite sea surface temperature data and aerial survey data to identify an upper (28 C) and lower (13.3 C) thermal limit to preferred loggerhead sea turtle temperatures. The available temperature range for the turtles to occupy, during this study (May 1991 to Sept. 1992), was 4.9 C to 32.2 C. These thermal limits fall within the ranges previously identified in the laboratory. This study suggests that sea turtles are not geographically randomly distributed but stay within preferred temperature ranges which are seasonally variable.

Recent collections from the Conasauga River system revealed the presence of Gambusia holbrooki, previously unreported in the Coosa River portion of the Mobile River drainage. We analyzed Gambusia specimens in 36 collections from the Conasauga River system to determine the relative distribution of G. affinis, G. holbrooki, or their hybrid progeny. We used gonopodial characters and ray counts from the anal and dorsal fins, which required reconciling differences among published accounts, to make species determinations. We counted all fin rays separately for dorsal and anal fins and recommend this method to clarify discrepancies among previous reports. This method yielded counts of seven dorsal and 10 anal rays for G. affinis and eight dorsal and 11 anal rays for G. holbrooki. Both species and their hybrids were collected in the Conasauga River system. Gambusia affinis is widespread in the Conasauga River system and is presumably native. Gambusia holbrooki currently has a limited distribution but appears to be expanding its range. We attribute the occurrence of G. holbrooki to human introduction.

I investigated seasonal predation on arboreal egg masses of four hyperoliid frogs by larvae of ephydrid and phorid flies in the Kibale National Park, Uganda. The egg masses of Hyperolius lateralis, H. cinnamomeoventris, H. platyceps, and H. kivuensis were all vulnerable to dipteran predation. Frequency of predation varied considerably among species, ranging from 61% for H. lateralis to 17.5% for H. kivuensis. Inoculation experiments demonstrated that ephydrid larvae cause high embryonic mortality within a clutch (25–97%) and that fly infestation results in significantly smaller hatching size for surviving tadpoles. Hyperolius reproduction and egg predation rates varied seasonally. Predators were selective during the wet seasons when frog breeding activity was highest, preferentially selecting H. lateralis and H. cinnamomeoventris and avoiding H. kivuensis clutches. Fly predation was random during the dry season. High clutch infestation rates and within-clutch mortality suggest that predation by dipteran larvae plays an important role in determining larval recruitment for arboreal egg-laying hyperoliids at these sites.

Male Pimephales notatus produce sounds during aggression associated with the breeding season. Females were not found to produce sounds during this study. Males produced sounds while in the nest cavity, chasing other fish, and during escalated aggressive displays. We identified four sound types characterized by differences in pulse duration and interval, which may be part of a continuum of sound parameters. The sound types were produced singly, in series, or as complex sounds composed of various combinations of three of the sound types. Complex sounds were made under all behavioral contexts and by all males studied. The mechanism of sound production in this species is unknown.

Genetic analyses of contact zones between closely related taxa are critical to an understanding of reproductive isolation between species. We evaluated allelic frequencies and external morphology from one such contact zone between two members of the Eurycea bislineata complex (i.e., E. cirrigera and E. wilderae). We found that, within this zone of contact, these presumed species had significantly different frequencies of alleles at three loci. In addition, these sympatric forms were significantly different in lateral mottling pattern, tail color, and length of tail stripe. These morphological patterns were identical to those used to describe the original subspecies E. b. cirrigera and E. b. wilderae. Evidence from this zone of contact supports the hypothesis that these forms are separate species. Moreover, there is evidence of ecological and/or reproductive character displacement among these species when in sympatry.

Young Black Snapper, Apsilus dentatus (Lutjanidae), were observed to mimic Blue Chromis, Chromis cyanea (Pomacentridae), in the Cayman Islands. The behavior may explain its juvenile coloration and depth preference. The mimicry probably has not been previously recognized because of the rarity of A. dentatus at scuba diving depths. The geographic ranges of the black snapper (insular West Indies) and the other known blue-chromis mimic, the Blue Hamlet, Hypoplectrus gemma (Serranidae, Florida, Belize), are mutually exclusive. Only three snapper species are known mimics, all of Chromis spp. Multiple-species mimicry of the same model species is uncommon in fishes, and this is the first record of such for the Atlantic.

Wild-caught and market-derived adult specimens of the Dwarf Crocodile Osteolaemus tetraspis osborni, caught in forests bordering the Congo and Oubangui Rivers in the northern Congo Republic, were examined for food residues in the stomach and pentastomid infections in the lungs. Stomach content analysis revealed that Osteolaemus was an opportunistic predator, taking a variety of invertebrates and small vertebrate prey in the dry season. Three species of pentastomids infected the lungs (prevalence 81%), representing three genera (all belonging to the family Sebekidae); every specimen was identified to instar. Two species, Agema silvaepalustris and Alofia parva, were represented by substantial numbers of infective larvae. Because this instar is also thought to occur in fish intermediate hosts, we postulated that some transmission continued in the dry season. Amphibious catfish (Clarias sp.) were common in swamp forest pools and may be the putative intermediate host.

Recent awareness of amphibian declines has raised the need for effective monitoring programs. Call surveys are a standard approach to monitoring populations of most anuran species. Temporal variation in calling activity, however, may result in failure to detect some species. Automated recording systems (ARS) allow consistent sampling for extended periods with little or no disturbance to calling anurans. We used an ARS to measure temporal variation in anuran calling activity during the summer of 1997 at a Carolina bay on the U.S. Department of Energy's Savannah River Site, South Carolina. We documented considerable interspecific variation in calling activity, a phenomenon that, using traditional call survey techniques, would result in failure to detect some species. In particular, we found that Southern Leopard Frogs (Rana sphenocephala), thought to breed only in early spring and fall in the region, called consistently from midnight until dawn during July. Because protocols for most call surveys dictate that the listener survey only during early evening hours, most call surveys would not detect the presence of this species. Our results indicate that temporal variation in anuran calling activity warrants further investigation and should be considered when developing anuran monitoring programs.

To test whether a pulse of testosterone reported in young male garter snakes also occurs in related snakes, testosterone levels were measured in 18 male water snakes (Nerodia sipedon) belonging to four litters at 5–6, 16–17, 29–30, and 250–267 days of age. Testosterone levels were uniformly low over the first 30 days of life but increased significantly by 250–267 days of age; there were also significant differences among litters in levels of this hormone by that time.

Palatability of Hemidactylium scutatum eggs was examined in a factorial experiment. Eggs of Hemidactylium and Desmognathus ocoee, which are known to be palatable, were offered to carabid beetle species collected from pond and stream habitats. Beetles collected from a pond habitat did not eat salamander eggs of either species, suggesting that they do not include salamander eggs in their diet regardless of palatablility. Beetles collected from a stream habitat punctured the same number of eggs of both species but consumed a much greater number of D. ocoee eggs. These results suggest that eggs of Hemidactylium contain a toxic or noxious chemical repellant in the jelly layer and may help to explain lack of nest defense and desertion in Hemidactylium and other caudate species.

We studied the occurrence of threat display as a defensive behavior at different temperatures in two large-sized (Gallotia simonyi and Gallotia stehlini) and two small-sized (Gallotia atlantica and Gallotia caesaris) lacertids from the Canary Islands. Lizards were chased on a linear track at five temperatures (24, 28, 32, 36, and 40 C). Only adult individuals of the two large-sized species sporadically adopted the threat display, and G. stehlini used the display more often than did G. simonyi. Among these, there was no clear pattern of relationship between temperature and probability of display nor differences between sexes.

Oviposition site selection was investigated in Pleurodema borellii, a leptodactylid frog from Northern Argentina. We monitored the breeding activity of P. borellii during six months at two different sized pools, which were 15 m apart. Calling males, mating pairs, number of foam nests, and metamorphosing tadpoles were recorded. When a pool filled with growing tadpoles, females avoided it and went to the other pool. Two experiments, foam nest transfers to the pool filled with tadpoles and the creation of artificially tadpole-dense populations, were conducted. Results suggest that females may be assessing whether to oviposit at a specific location, based on tadpole presence and tadpole density.

The reproductive strategy of Podarcis milensis exhibits some peculiarities when compared with other congeners. Males and females attain sexual maturity at a minimum body size of 47 and 42 mm SVL, respectively, both at an age of about one year. Podarcis milensis has a very small clutch size, with a mean of 1.73 and a range of 1–3 eggs, and produces multiple clutches annually. Both sexes exhibit a prolonged reproductive period extending from January to August.

The overlap pattern between the parietal scale and the upper anterior temporal scale is a useful character in the large scincid lizard genus Mabuya. In the primitive pattern, the parietal overlaps the upper anterior temporal, and in the derived pattern, the upper anterior temporal overlaps the parietal. The primitive condition occurs in most species from Africa, at least some of the species from the Cape Verdes, and in all species from the Americas and the Seychelles. The derived condition occurs in most species from southeast Asia, some south Asian species, all endemic Madagascan species, and a few mainland African species.