The phylogenetic relationships of genera of the family Centrarchidae and its affinities to the Elassomatidae were examined using the mitochondrial DNA sequences of the cytochrome b gene. A total of 32 individuals representing 16 species from nine genera of centrarchids were sequenced. Outgroup were drawn from other perciform families including several families previously proposed to be closely related to the Centrarchidae. Phylogenetic analysis was conducted using the optimality criteria of maximum parsimony with two weighting schemes and using the maximum likelihood method. A priori and a posteriori alternative hypotheses of relationships within the Centrarchidae were investigated using the Shimodaira and Hasegawa Test. The results of all analyses support the monophyly of the Centrarchidae, although the interrelationships of centrarchid genera differed between analyses. Elassoma was never recovered as the sister taxon to the Centrarchidae; however, the sister relationship of these taxa could not be rejected. Additional data are required to unambiguously resolve relationships among centrarchid genera and determine the relationship of the Centrarchidae to other perciforms.

The Homalopsinae (Oriental-Australian rear-fanged water snakes) is a small (34 species, 10 genera) colubrid subfamily notable for its ecological and morphological diversity. Despite considerable interest in the ecology and evolution of this group, phylogenetic relationships within the subfamily are poorly resolved. We present the results of a molecular phylogenetic study of the homalopsines based on partial sequence of three mitochondrial genes (12S and 16S ribosomal RNA and cytochrome b) from 14 ingroup species, five Old and New World natricines and the Old World colubrid, Dinodon semicarinatus. Maximum likelihood analysis in combination with bootstrapping and Bayesian Markov chain Monte Carlo methods for assessing phylogenetic confidence revealed that the single most likely topology contained a number of well-supported nodes. Homalopsine monophyly was strongly supported with respect to the outgroups included in our study. Cantoria violacea, a morphologically distinctive marine crustacean eater, formed the sister group to the rest of the homalopsines. Enhydris, the most species-rich genus in the subfamily, was polyphyletic with respect to other homalopsines although five morphologically and ecologically similar species formed a well-supported clade. The marine crustacean eaters Fordonia leucobalia and Gerarda prevostiana, also formed a novel clade. We discuss the evolutionary and ecological implications of this phylogeny for the Homalopsinae.

Phylogenetic relationships among taxa of the annual fish subtribe Cynolebiatina are examined, based on 57 morphological characters in 29 terminal taxa, including two basal species of the well-supported monophyletic genus Cynolebias Steindachner, 19 valid species of Austrolebias Costa, and all five valid species of Megalebias Costa. A clade comprising Austrolebias and Megalebias is strongly supported (bootstrap value 96%) and defined by five nonhomoplastic synapomorphies: deep urohyal, long cleithrum, dorsal and anal fins of male short and rounded, frontal squamation F-patterned, and a transverse supraorbital bar. Monophyly of Megalebias is supported (bootstrap value 98%) by 12 synapomorphies, four unambiguous: reduced basihyal, anteriorly expanded anterolateral tip of lateral process of sphenotic, curved lacrimal, and posteroventrally directed suborbital stripe. Monophyly of Austrolebias (bootstrap value 96%) is corroborated by a reduced basihyal ossification, a laterally expanded basihyal cartilage, an anteriorly positioned dorsal fin of male, and a spotted color pattern in female. Evidence supporting intergeneric and intrageneric relationships is discussed.

Relações filogenéticas entre taxa da subtribo de peixes anuais Cynolebiatina são examinadas, com base em 57 caracteres morfológicos em 29 taxa terminais, incluindo duas espécies basais do bem corroborado gênero monofilético Cynolebias, 19 espécies válidas de Austrolebias Costa, e todas as cinco espécies válidas de Megalebias Costa. Um clado compreendendo Austrolebias e Megalebias é fortemente sustentado (valor de bootstrap 96%), e definido por cinco sinapomorfias não homoplásticas: uro-hial alto, cleitro longo, nadadeiras dorsal e anal de macho curtas e arredondadas, escamação frontal em padrão F, e uma barra supraorbital transversal. Monofiletismo de Megalebias é sustentado (valor de bootstrap 98%) por 12 sinapomorfias, quatro não ambíguas: basi-hial reduzido, ponta antero-lateral de esfenótico expandida anteriormente, lacrimal encurvado, e faixa suborbital direcionada postero-ventralmente. Monofiletismo de Austrolebias (valor de bootstrap 96%) é corroborado pela reduzida ossificação do basi-hial, expansão lateral de cartilagem basi-hial, nadadeira dorsal de macho posicionada anteriormente, e padrão de colorido maculado em fêmea. Evidências sustentando relações inter e intra-genéricas são discutidas.

Developmental plasticity and large egg size are traits that can benefit offspring early in life, but their coevolution has rarely been examined. I experimentally manipulated water depth and food availability of larvae of the frog Crinia georgiana, a species with a large egg size that breeds in shallow seeps that often dry before tadpoles have metamorphosed. Tadpoles that were never fed completed metamorphosis at about the same time as tadpoles under constant conditions, although at much smaller body sizes and with higher mortality. Except for the earliest stage tested (Gosner stage 28), tadpoles that experienced a decrease in water depth accelerated development and completed metamorphosis earlier than tadpoles kept in constant conditions. Acceleration was not possible when food was withheld, except when water levels were also lowered and only during later developmental stages. Because acceleration of development was initiated at earlier larval stages than in small-egged species that breed in ephemeral water bodies, these data suggest that phenotypic plasticity and maternal provisioning strategies can coevolve to help larvae cope with unpredictable aquatic environments.

In 1926, Norman described the cave fish population in the Cumaca Cave of Trinidad, West Indies, as a new troglomorphic (blind/depigmented) genus and species, Caecorhamdia urichi, based on its reduction in eye size and pigmentation. Later studies indicated that this was just a cave population of the widely distributed epigean (surface, eyed/pigmented) catfish Rhamdia quelen. Beginning in the 1950s, a number of specimens were collected in the cave showing variability in eye size and pigmentation. In 2000 and 2001, we conducted field studies that included direct observation of individuals using infrared visual equipment (video cameras and night-vision goggles) and echo-sounders and also collected some individuals for behavioral research. We also examined all available specimens of the cave population that have been deposited in museums. Our results strongly suggest that the troglomorphic population has been completely replaced by the epigean one of the same species in as little as 50 years. We hypothesize that the most important reason for this replacement was the reinvasion of epigean individuals of R. quelen prompted by changes in precipitation regimes. Epigean individuals, because of their morphology, behavior, and ecological requirements, were well suited to outcompete troglomorphic individuals.

We determined group composition and foraging mode in a wild population of rupicolous rainbow skinks (Mabuya margaritifer) on rocky outcrops in a humid savannah of South Africa and examined diet, sexual dimorphism, and life-history traits in museum material. We also field-tested lizards for prey chemical discrimination. Males were larger than females in both body and head size. Both sexes reached maturity at 68 mm SVL, and females produced clutches of 2–9 eggs. Males excluded other males from their home range but shared overnight crevices with 1–4 females and 1–6 juveniles. Mabuya margaritifer were ambush foragers when only the amount of time spent moving (8%) was considered; however, other variables such as moves per minute (1.3) and average speed (0.01 m/s) suggest an intermediate foraging mode between active and ambush foraging for the population studied. Lizards spent most time on rock (81.5%) but also moved into vegetation (7.9%) and along the rock-vegetation interface (10.6%). Both sexes spent similar amounts of time in these microhabitats and were observed feeding in all three. Diet was dominated by termites, and overlap in prey types between sexes was high. In experimental tests for prey chemical discrimination, lizards tongue-flicked rarely, giving no indication of an ability to discriminate prey chemicals. Also, lizards observed in the field during focal observations performed few tongue-flicks. Based on these results, sexual dimorphism is best explained by sexual selection via male contest competition and not by ecological niche divergence.

A new species of the ceratioid anglerfish genus Gigantactis is described from a single specimen collected in the western North Atlantic. Clearly a member of the Gigantactis macronema-group, it is unique among members of this group and among all other described species of the genus in having a combination of features that includes a long illicium, unique escal morphology, and exceptionally long caudal-fin rays. A revised key to the species of the G. macronema-group is provided.

We studied variation in the population ecology of dusky gopher frogs, Rana sevosa Goin and Netting, in southern Mississippi from 1996–2001. Specifically, we measured adult size structure, adult survivorship, residency length within the pond, and juvenile recruitment using a drift fence that completely enclosed the study pond. Population size structure shifted among years because of lack of recruitment in previous years, adult mortality, and differential age at maturity. Age at maturity was 6–8 months for males and 24–36 months for females. Annual survival ranged from 65 to 92%; however, the rate at which adults returned to breed among years was low (16–22%). The average number of seasons that adults bred was 1.2, although nine individuals bred in 3–5 seasons. Our data suggest that R. sevosa has high population turnover among years and that most adults live less than 7 yr. Because of the low rate of return of adults among years and complete isolation of the population, the viability of the population is contingent on consistent recruitment of juveniles with minimal years of reproductive failure.

A new scorpionfish species is described from Fiji and Enewetak in the Marshall Islands, where it was collected from high-energy habitats. It is most similar to Scorpaenodes parvipinnis, with which it coexists, but differs in having four suborbital spines instead of five or more, by lacking a spine on the lachrymal ridge, and in coloration. It differs from S. parvipinnis and all other species of Scorpaenodes by having the second spine on the suborbital ridge extending dorsally above the lower orbit margin.

A population of Fowler's toads, Bufo fowleri, was studied between 21 April and 20 June 1992 in Medford, NJ. I obtained records of body size, body temperature, and focal samples of calling activity from 126 males over two months of chorus activity. Assuming that vocalizing is energetically costly, my primary purpose was to investigate whether calling effort was correlated with body size, growth rate, or chorus tenure. In addition, given that the body temperature of calling males over the breeding season varied by more than 10 C, these data provided an opportunity to identify correlations among body temperature and measurements of calling behavior. I made focal observations of calling activity on 16 nights. Mean nightly calling efforts were relatively constant throughout the study (range 10.8–14.2 sec of vocalizing per minute) with only 4% of the variation in individual calling effort explained by body temperature. Individual calling effort was weakly positively correlated to body size. Males tended to gain mass over 18 continuous nights of minimal chorus activity and to lose mass over 10 nights of continuous chorusing. Larger males were more likely to lose mass during these 10 nights. Growth rates were not correlated with calling effort. Chorus tenure was skewed; males vocalized a median of three nights (range 1–15 nights). Chorus tenure was not correlated with individual calling effort, body size or growth rate. However, chorus tenure was the only variable significantly correlated with mating success. In conclusion, although these data are consistent with the hypothesis that calling activity is energetically costly, it is unclear why certain males had higher chorus tenures than others. When compared to data on calling effort in other anuran species, B. fowleri appear to be calling near their physiological maxima.

A new species of Characidium is described from tributaries of the rio Paranã (Tocantins drainage), in Goiás State, central Brazil. Characidium stigmosum is diagnosed by the presence of dark marks along the sides of the body, which are associated with the vertical bars that occur in most species of Characidium. These marks are vertically oriented elliptical, except one or two anteriormost marks which may be roundish or horizontally elongate; there is usually one mark for each bar above abdominal area and two marks for each bar on posterior half of body; lower marks are slightly offset posteriorly. Characidium stigmosum shares apomorphic traits with the clade comprised of Characidium rachovii, Characidium occidentale, Characidium orientale, and Characidium vestigipinne.

Individual variation in antipredator behavior may be influenced by ecological factors, such as ambient temperature and predation pressure, and by intrinsic factors, such as physiological condition. We tested the hypothesis that both types of factors interact to induce a specific antipredator response in the treefrog, Scinax hiemalis. When disturbed by the threat of predation, individuals of this species exhibit either a passive response by feigning death or immobility, or an active escape response by jumping away. We examined the responses of 24 adult male S. hiemalis to simulated predation in the laboratory at 10, 15, and 20 C. In addition, responses from a single stimulus were compared with those from a series of stimuli. We determined physiological condition from measures of body length and mass, jumping performance, aerobic metabolism, and estimated energy reserves. Temperature had the most influence on antipredator behavior, with more frogs exhibiting passive responses at 10 C than at higher temperatures. If stimulated more than once, the proportion of active responses increased at all three temperatures. Larger individuals were more likely to exhibit an active response, but no mass-independent physiological variables were related to response type. These results suggest that frogs respond to both extrinsic and intrinsic factors that may affect their behavioral performance.

Corydoras difluviatilis, new species, is described from the upper rio Paraná and the upper rio São Francisco, Brazil. The new taxon differs from its congeners by three exclusive features: the posterior pectoral-spine serrations restricted to its proximal half, and the parapophyses of the fourth free vertebra reduced and separated from each other, not fused into a haemal arch. The new species has several plesiomorphic character states relative to the assemblage composed of Brochis and most Corydoras species, such as absence of contact between the supraoccipital and nuchal plate, reduction of the ossified portion of hypobranchial 2, and well-developed mesial expansions of the first and second infraorbitals, indicating its basalmost position within the genus.

Populations of robust salamanders belonging to the plethodontid salamander genus Batrachoseps (subgenus Plethopsis) from the southern Sierra Nevada and adjacent regions represent a previously unknown species here described as Batrachoseps robustus. The new species is robust, with a short trunk (17–18 trunk vertebrae) and well-developed limbs. It differs from its close geographic neighbor, Batrachoseps campi, in lacking patches of dorsal silvery iridophores and in having (typically) a lightly pigmented dorsal stripe, and from Batrachoseps wrighti in being more robust, having more trunk vertebrae, and in lacking conspicuous white spots ventrally. This species is widely distributed on the semiarid Kern Plateau of the southeastern Sierra Nevada and extends along the east slopes of the mountains into the lower Owens Valley; it also is found to the south in the isolated Scodie Mountains. It occurs at high elevations, from 1615–2800 m, in areas of low rainfall and high summer temperatures.

Cyprichromis zonatus, a new cichlid species, is described on the basis of 21 specimens from the Zambian coast of Lake Tanganyika. It differs from its congeners, Cyprichromis leptosoma, Cyprichromis microlepidotus, and Cyprichromis pavo, by having 39–43 scales in longitudinal line (vs 57–71 in C. microlepidotus), 29–36 upper lateral line scales (vs 49–60 in C. microlepidotus), usually 14 or 15 dorsal fin spines (vs 12 or 13 in C. leptosoma, usually 16 in C. pavo), a generally deeper body (24.5–30.3% SL vs 23.1–26.2% in C. microlepidotus, 24.5–26.4% in C. pavo), deeper caudal peduncle (9.9–11.1% SL vs 8.4–9.9% in C. microlepidotus, 9.3–9.9% in C. pavo), longer pectoral fin (27.1–33.0% SL vs 23.1–27.4% in C. leptosoma, 23.0–27.3% in C. microlepidotus), caudal fin dichromatism absent (vs blue and yellow dichromatism in male C. leptosoma), and three or four distinct vertical bands beneath the dorsal fin base in live males (vs absent or very indistinct in other species).

We describe a new species of narrow-mouthed frog of the genus Kaloula from the volcanic mountains of southern Luzon Island (Mt. Banahao, Mt. Isarog, and Mt. Mayon) and adjacent Polillo Island, Philippines. On the volcanoes of southern Luzon, the new species is found in habitats ranging from small dry stream beds to stationary pools of rivers in mid- to upper montane primary forest. On Polillo Island, the new species has been found near quiet streams in selectively logged primary forest and second growth near sea level. The new species presumably is allied to Kaloula rigida (a forest species endemic to northern Luzon Island) and to Kaloula picta (a more widespread Philippine endemic that is found in a variety of habitats) as indicated by possession of narrow disks on the digits and by the presence of supernumerary tubercles on the palmar surface of the manus. It differs from these species by its smaller body size, reduction of webbing on toes, absence or extreme reduction of outer metacarpal tubercles, and by characteristics of the advertisement call.

A new species of the characid genus Astyanax is described. The species is currently known only from two localities in headwater streams of arroyo Yabotí-Guazú, a tributary of the upper río Uruguay, in Argentina. Astyanax paris n. sp. can be easily distinguished from all congeneres by the combination of relatively shallow body (34.9–39.4% SL), three or four maxillary teeth, fifth tooth of the inner premaxillary series posterior to main series, first humeral spot followed by a second one vertically elongated, sometimes wider than the first, a caudal spot continued onto the middle caudal fin rays, large dark chromatophores on the cheek, 34–36 perforated scales in the lateral series and, iv–v, 20–22 anal fin rays.

A new frog species of the genus Mantidactylus is described from the lowland areas of northwestern Madagascar known as the Sambirano Region. Mantidactylus madinika reaches 11–13 mm snout–vent length in males and 15–16 mm in females and is thereby the smallest species in the family Mantellidae. It is included in the subgenus Blommersia based on external morphology but differs from other species of the subgenus by its relative finger length. Several features of the new species (only slightly bifid tongue, absence of vomerine teeth, reduction of maxillary teeth, absence of dark pigment on oocytes) are similar to the states observed in the genus Mantella, which is known to be phylogenetically nested within the paraphyletic Mantidactylus. Miniaturization in the ancestor of Mantella may explain several of the derived character states in this genus.

A new species of Otocinclus, Otocinclus tapirape, is described. The new taxon differs from other species of the genus by the following combination of characters: low number of trunk lateral plates; canal-bearing plates of trunk median plate series truncated, restricted to the anterior field; presence of iris diverticulum; expanded subnasal lamina on lateral ethmoid; and nuchal plate narrow. The phylogenetic relationships of the new species are ((Otocinclus affinis, Otocinclus flexilis)(Otocinclus xakriaba (Otocinclus tapirape, remaining Otocinclus species))).

A new lizard species of the genus Cnemidophorus (Teiidae) is described from Dunas do Abaeté, Salvador Municipality, Bahia State, northeastern Brazil, where it occurs in sympatry with Cnemidophorus ocellifer. The new species is characterized by normally having three rather than four supraoculars as in the other known members of the ocellifer complex. Its tail is bright blue-green, in contrast to the brownish tail of C. ocellifer. The new species differs conspicuously from the closely related congeners C. ocellifer, Cnemidophorus nativo, and Cnemidophorus littoralis in color pattern and in certain meristic characters, such as the number of femoral pores, number of subdigital lamellae on fingers and toes, and counts of transverse ventral scale rows.

The lack of information surrounding natural history and ecology of the endangered Morelet's crocodile (Crocodylus moreletii) has prompted a baseline study of the population genetics for this species. Nine microsatellite loci have been used to estimate genetic structure within and gene flow patterns among crocodiles (using a recently described maximum likelihood approach) from seven localities in north-central Belize. Individuals from the seven localities grouped into four apparent populations. Within localities, a high degree of genetic heterogeneity was observed. Among all localities, some subdivision was present (F_ST = 0.062; R_ST = 0.100). Furthermore, among the apparent populations, we found a significant correlation between geographic distance and genetic subdivision. Our findings suggest a relatively high level of migration among populations (Nm = 5.15) and are consistent with an isolation-by-distance model of gene flow. Two contiguous subpopulations in particular, New River and New River Lagoon, may form an important source for genetic variation for smaller populations throughout the region. These data will allow us to test hypotheses of relatedness among C. moreletii for other drainages in Belize and will be useful in optimizing future management programs for C. moreletii.

We examined the phylogenetic relationships among members of the Hybopsis amblops species group in a total evidence cladistic analysis using DNA sequence data from regions of three mitochondrial genes and previously published morphological data. Molecular characters consisted of 120 informative sites from 811 bases of the 12S, 82 informative sites from 571 bases of the 16S gene, and 214 informative sites from 519 bases from the ND2 protein-coding gene. Morphological characters consisted of 14 transformation series previously published by R. L. Mayden in 1989. Two most parsimonious trees were found with the topologies: (Hybopsis hypsinotus ((Hybopsis lineapunctata, Hybopsis rubrifrons) (Hybopsis amblops (Hybopsis amnis (Hybopsis winchelli, Hybopsis sp.))))) and (Hybopsis hypsinotus (Hybopsis amblops ((Hybopsis lineapunctata, Hybopsis rubrifrons) (Hybopsis amnis (Hybopsis winchelli, Hybopsis sp.))))).

Collection of eels of the families Muraenidae and Congridae is often hampered by logistical and procedural difficulties. Sea kraits of the genus Laticauda may be useful bioassays for moray and conger eels in the western Pacific Ocean. Some widely distributed species of Laticauda appear to prey exclusively on eels, and these eels are readily palpated from snakes after they return to land to digest their prey. We removed 79 eels from 276 snakes on the island of Efate, Republic of Vanuatu, during November and December of 2000. Species diversity inferred from these eels was markedly different from the diversity inferred from eels from Vanuatu deposited in the Australian Museum, perhaps reflecting differential abilities of snakes and humans to capture certain eel species. This bioassay technique is inexpensive and logistically simple and may prove complementary to more traditional collecting methods.

Lepomis hybridization occurs frequently in natural systems. Previous investigations of sunfish hybridization have focused on courtship behavior of interspecific pairs. We observed spawning in Lepomis nesting colonies where interspecific nest intrusions occurred. Nesting male Lepomis microlophus (redear sunfish) attempted to fertilize eggs in the adjacent nests of spawning Lepomis megalotis (longear sunfish). Male sunfish commonly employ this reproductive tactic in the nests of conspecifics. When colonies contain more than one species, hybridization may occur through interspecific nest intrusion by males on adjacent nests.

Concerns about the effects of formalin fixation have largely precluded the use of fluid-preserved museum specimens in stable isotope studies. We sought to determine the magnitude, direction, and causes of formalin-induced change in isotopic values of carbon, nitrogen, and sulfur by examining differences in isotopic signatures between paired fresh-frozen fish tissue samples and tissues subjected to fixation and preservation procedures employed in natural history museums. Several factors were investigated as predictors of formalin-induced change: (1) duration of formalin fixation and ethanol preservation; (2) lipid extraction by formalin and ethanol; and (3) differences in isotopic content among formalin preparations from different manufacturers. Formalin fixation caused a decrease in the δ¹³C-values across samples and treatments (mean decrease in preserved tissues of 1.1‰ for all treatments, SD = 0.8). The magnitude of depletion depended on the isotopic composition of formalin used for fixation, but not duration of fixation or extraction of lipids. δ¹⁵N-values were enriched for all samples and magnitude was independent of brand of formalin and all other factors studied (mean increase of 0.5‰ for all treatments, SD = 0.3). δ³⁴S-values were not systematically affected by formalin under any conditions of the tests. Formalin-induced changes in carbon, nitrogen, and sulfur isotope values of fish tissue were small compared to changes expected from natural fractionation processes that are of interest in ecosystem studies. Thus, specimens held by natural history museums offer a potentially important source of predisturbance material for quantifying historical change in nutrient cycles and food webs in aquatic ecosystems.

Through a series of odor preference and sexual activity tests, the response of male western mosquitofish, Gambusia affinis, to female odors was investigated. Male mosquitofish prefer female odors to male odors and plain water, indicating that female odors function as a sex attractant. In odor preference tests, males did not show preferences among odors from nongravid, gravid, and parturient females. However, odors from females in different stages of the reproductive cycle induced different sexual activities from males. Odors from gravid females increased copulation trials, whereas those from parturient females increased male-male interactions without changing copulatory activity. These results suggest that (1) female western mosquitofish may produce sex pheromones and (2) female pheromones from different stages of the reproductive cycle stimulate different male sexual activities, suggesting that males may discriminate parturient females from others based on pheromonal output. In populations where the operational sex ratio (OSR) is female-biased, the discrimination of reproductive stages of females by males could increase male reproductive success by allowing males to avoid spending mating efforts with females whose eggs they are unlikely to fertilize.

Hemoglobin polymorphism in all 10 genera of emydid turtles was examined by isoelectric focusing. Two major (highly concentrated) forms of hemoglobin were revealed in all turtles examined. Cathodal electromorphic bands of hemoglobin (Hb A) demonstrated isoelectric points (pI) 7.6–8.3, and anodal bands (Hb D) demonstrated isoelectric points 5.2–6.1. The most common forms of Hb A (pI 8.3) and Hb D (pI 6.0) were shared by Pseudemys, Graptemys, Malaclemys, and Trachemys. Relatively little intrageneric variation was observed except among species of Clemmys, which lends support to the hypothesis that the genus Clemmys is not monophyletic. Ontogenetic hemoglobin polymorphism was observed in Trachemys scripta elegans and Trachemys scripta troostii.

To investigate changes in the biology of blacknose dace (Rhinichthys atratulus) populations accompanying watershed urbanization, we sampled dace from four watersheds in the Baltimore, Maryland area, representing a gradient from urbanized to rural conditions. Dace from the most urbanized watershed grew to greater standard lengths during their first year of life when compared to dace from other watersheds but grew little during their second year. Dace from the other watersheds showed slower growth during their first year but continued to grow through age II. Approximately 90% of age I dace from the most urbanized watershed were mature at age I, whereas only 25% of age I dace from the other watersheds were mature. Dace from the most urbanized watershed also reached maturity at shorter standard lengths than dace from the other watersheds. Growth and maturation of dace from the most rural watershed were similar to those reported for dace from other regions. We conclude that watershed urbanization results in increased growth rates of young blacknose dace, and in heavily urbanized (> 90% urban land use) watersheds, decreased age and size at maturity.

The genus Leptodactylus provides an example among anurans in which there is an evident tendency toward terrestrial reproduction. Herein we describe a new reproductive mode for the frog Leptodactylus podicipinus, a member of the “melanonotus” group. This new reproductive mode represents one of the intermediate steps from the most aquatic to the most terrestrial modes reported in the genus. Three reproductive modes were previously recognized for the genus Leptodactylus. However, based on our data, and on several studies on Leptodactylus species that have been published since the last reviews, we propose a new classification, with the addition of two modes for the genus.

The family Gobiidae is the largest family of marine fishes, yet microhabitats of most gobies are poorly known. We sampled different coral reef macrohabitats from Jamaica and Grand Cayman to identify microhabitats occupied by three species of the genus Elacatinus. Elacatinus gemmatus and Elacatinus pallens were found in association with burrows created by the chiton, Choneplax lata. Between island differences in microhabitats occupied by Elacatinus dilepis could represent a shift because of reef degradation in Jamaica.

Comparisons of sonic muscle width, body cavity length, and sonic muscle innervation patterns were made for three species of sciaenids: weakfish, Cynoscion regalis; Atlantic croaker, Micropogonias undulatus; and spot, Leiostomus xanthurus. Body cavity length and sonic muscle width (rostrocaudal extent), both normalized for TL, were significantly different among the three species, increasing from spot to croaker to weakfish. However, the percentage of the body cavity length including sonic muscle was greater in the croaker and weakfish than in the spot. The sonic muscles of sciaenids are innervated by a number of true spinal nerves rather than by paired occipital spinal nerves. The number of sonic nerves increased from spot (4–5 nerves from vertebrae 4–9) to croaker (6–8 from vertebrae 3–10) to weakfish (8–9 nerves from vertebrae 3–12), paralleling the increase in muscle width. Although the number of nerves and their vertebra of origin varied within each species, they were bilaterally symmetrical within an individual. The spinal nerves emerged from two (dorsal and ventral) foramina in croaker and spot and from the sole foramen observed in weakfish vertebrae. Therefore, a longer body cavity supports a wider sonic muscle that is innervated by a greater number of spinal nerves.

Three individuals of a whipnose anglerfish, Gigantactis sp., were observed near the bottom in the North Central Pacific Ocean. An image from one of three videotape sequences discussed herein represents the first photograph of live behavior in members of the fish family Gigantactinidae. Foraging and escape behaviors included drifting and swimming upside-down. Close association with the bottom while drifting suggests foraging on benthic organisms. Escape behaviors also indicate a lack of stamina consistent with a sit-and-wait bathypelagic predator.

An examination of the holotype of Apostolepis sanctaeritae Werner, 1924, allows confirmation and redescription of this species with additional data. This species is most similar to Apostolepis assimilis and not to Apostolepis cearensis or Apostolepis flavotorquata, as suggested by previous investigators. A comparison and key for identification of species with similar color patterns is provided.