The phylogenetic relationships of the family Pomacentridae (Teleostei: Perciformes) were explored using mitochondrial DNA sequence data from the mitochondrial transfer RNA Phe, 12S mitochondrial ribosomal RNA, and 16S mitochondrial ribosomal RNA genes (1510 base pairs) for 23 species in 14 genera of pomacentrids. Outgroups were drawn from the other three putative families of the suborder Labroidei. Total evidence analyses using both weighted and unweighted parsimony criteria were performed. A weighting scheme was employed to account for site saturation. The results find a monophyletic Pomacentridae and subfamily Amphiprioninae. Premnas is recovered within Amphiprion, thereby rendering Amphiprion paraphyletic. The Chrominae is not monophyletic, because one putative member (Mecaenichthys) appears in a more basal position in the tree. These results do not support a monophyletic Pomacentrinae but rather suggest that it is a polyphyletic assemblage. The genus Pomacentrus appears to be the sister group to the Amphiprioninae. There is support for the monophyly of Abudefduf, Dascyllus, Pomacentrus, and Stegastes. A monophyletic group consisting of the Amphiprioninae, Pomacentrus, Neoglyphidodon, and Amblyglyphidodon was observed. Higher level relationships within the Pomacentridae are not well supported, and additional data are required.

Patterns of population subdivision and gene flow were quantified using allozymes in three sympatric species of natricine snakes from the island region of western Lake Erie. Species share similar population history (post-Pleistocene range expansion followed by subdivision into island and mainland demes) and life-history characteristics. However, species differ in anticipated rates of gene flow because of differences in body size and degree to which they use aquatic habitats. Significant population subdivision was present in all three species, and isolation by distance was evident in water snakes (Nerodia sipedon) and, to a lesser degree, in brown snakes (Storeria dekayi) but not in garter snakes (Thamnophis sirtalis). As predicted, water snakes, the largest and most aquatic of the three species, showed significantly less population structure (lower values of F_ST) than did the smaller and more terrestrial garter snakes and brown snakes. Furthermore, variance in locus-specific estimates of F_ST was highest for brown snakes, intermediate for garter snakes, and lowest for water snakes. Estimates of F_ST obtained in this study are similar in magnitude to those reported for other snake species that have undergone post-Pleistocene range expansion but are lower than those reported for some southern U.S. species that may have experienced longer periods of isolation.

Phylogenetic relationships for 14 of 35 currently recognized Dasyatis species (Dasyatis americana, Dasyatis brevis, Dasyatis centroura, Dasyatis geijskesi, Dasyatis guttata, Dasyatis kuhlii, Dasyatis lata, Dasyatis longus, Dasyatis margaritella, Dasyatis pastinaca, Dasyatis sabina, Dasyatis say, Dasyatis violacea, and Dasyatis zugei), Pastinachus sephen (sometimes referred to as Dasyatis sephen), one Indo-West Pacific Himantura (Himantura gerrardi), and four outgroups (Gymnura micrura, Urobatis jamaicensis, Taeniura lymma, and amphi-American Himantura schmardae) were elucidated using parsimony analysis of 32 morphological characters. One most-parsimonious tree of 116 steps (CI = 0.345, HI = 0.655, RI = 0.64) was found. The analysis refutes monophyletic Dasyatis and Himantura and reveals Dasyatis kuhlii, D. violacea, and P. sephen to be basal among other ingroup species, with D. kuhlii as the most basal species. The genus Himantura is paraphyletic, with amphi-American H. schmardae as sister to a clade containing all species except Urobatis jamaicensis. Himantura gerrardi is nested well within Dasyatis as sister to D. margaritella and forms a clade with G. micrura and Dasyatis zugei. Sister species Dasyatis geijskesi and D. guttata form a clade with D. zugei, G. micrura, D. margaritella, and H. gerrardi. This clade is sister to a group containing sister pairs of D. centroura/D. lata and D. longus/D. americana. Dasyatis brevis and D. say are sister species. Neotropical Dasyatis are polyphyletic.

Effects of anoxic submergence (1, 5, and 20 h at 5 C) and subsequent aerobic recovery (1, 5, and 24 h at 5 C) on gene expression in organs of the anoxia-tolerant turtle Trachemys scripta elegans were examined. Differential screening of a cDNA library from brains of 20 h anoxia-exposed turtles selected two clones from Anoxic Turtle Brains, ATB1.22 and ATB2.4, as potentially up-regulated by anoxia. The insert of clone ATB1.22 had a single open reading frame that encoded a protein of 376 amino acids which was identified as mitochondrial cytochrome b (CYTb); the sequence was 99% complete and showed 72% of nucleotide residues and 76% of amino acid residues identical to those in the human sequences. Clone ATB2.4 contained an open reading frame encoding 322 amino acids with 65% nucleotide and 63% amino acid sequence identity with another mitochondrial protein, NADH-μbiquinone oxidoreductase subunit 4 (ND4). Northern blot analysis of the time course of gene expression in five organs during 20 h anoxia exposure and 5 h aerobic recovery revealed that Cytb transcript levels increased strongly in livers (5.8-fold within 1 h, remaining high over 20 h) and also in kidneys (rising to threefold higher than controls after 20 h). Nad4 transcript levels also rose strongly in livers (13-fold within 1 h anoxia) and remained approximately fivefold higher than controls over the remainder of the time course. Conversely, Nad4 transcripts in kidneys were unaffected by anoxia but strongly suppressed during aerobic recovery to only 10% of control values after 5 h recovery; transcripts were also reduced in skeletal muscle during recovery. The results suggest that up-regulation of selected mitochondrially encoded genes may be of functional significance to anoxia endurance in these facultative anaerobes.

Section Editor: R. E. Gatten Jr

Phylogenetic analyses based on complete nucleotide sequences of the mitochondrial cytochrome b gene were performed to determine generic assignment and composition of the Notropis dorsalis species group (Hybopsis vs Notropis) and to determine relationships among the five species within this group. Phylogenetic relationships were reconstructed at two levels: (1) a primary analysis of 14 species of shiners to determine placement of the N. dorsalis species group with respect to other shiner species and to determine whether the closely related Notropis buccatus is a member of this group; and (2) a secondary analysis of 32 individuals from the N. dorsalis species group to determine relationships among component species. In the primary analysis, the N. dorsalis species group was placed within genus Notropis, and N. buccatus was resolved as a member of the N. dorsalis species group. The within-species group phylogeny produced by the secondary analysis suggested a sister relationship between N. dorsalis and N. buccatus. This clade was found to be sister to remaining members of the N. dorsalis species group: (Notropis sabinae (Notropis longirostris (Notropis ammophilus and Notropis rafinesquei))).

Age and size at maturity are pivotal life-history traits through their effects on other key traits, such as annual and lifetime fecundity. We used skeletochronology to investigate the relationships among size (snout–vent length), age, and maturity in two populations of a small viviparous skink, Niveoscincus ocellatus, from Tasmania, Australia. The species occupies a wide geographic and climatic range within the temperate zone, and we chose populations from the climatic extremes of this range. Growth in N. ocellatus is rapid early in life but slows considerably after maturity in both sexes. Within sites, we found no difference in growth patterns or length at maturity between the sexes. However, there were large differences between sites. At our “warm” site, lizards were mature at three years of age at a relatively small size. Lizards from the “cold” site typically delayed maturity until their fourth year (although some males were mature at the end of their third year); as a result, they were significantly larger at maturity and thereafter remained larger for any age than did warm-site lizards. These patterns are consistent with predictions from models of the proximate influence of the thermal environment on growth and maturity patterns in squamate reptiles. Lizards from the cold site are born later in the season and have a shorter activity season prior to obligatory winter hibernation, and conditions for growth are less favorable in any particular month than at the warm site. Because delaying maturity is costly to current fecundity, we suggest that in N. ocellatus lifetime fecundity is enhanced at the cold site by additional growth and gains in future fecundity through the relationship between body length and reproductive output.

Cytochrome b sequences (1140 bp) from 16 species considered to be members of subgenus Notropis and several outgroup taxa were analyzed phylogenetically. Phylogenetic analysis of cytochrome b was sensitive to sampling of outgroup taxa, probably resulting from substitutional rate heterogeneity among outgroups. Maximum-likelihood analysis was more robust to these effects as compared to maximum parsimony. Both maximum parsimony and maximum-likelihood analysis supported removal of Notropis candidus and Notropis shumardi from subgenus Notropis. Monophyly of the 14 remaining species was supported by the maximum likelihood analysis. Regardless of the method of analysis or use of outgroup taxa, phylogenetic analysis of cytochrome b indicated strong support for the following hypothesis of relationships: ((Notropis rubellus, Notropis suttkusi), (Notropis amoenus, Notropis stilbius, ((Notropis atherinoides, Notropis oxyrhynchus), (Notropis amabilis, Notropis jemezanus)))). This phylogenetic hypothesis implies that morphological characters associated with increased olfaction were derived independently among members of subgenus Notropis, perhaps in response to life in more turbid habitats.

During the Australian summers of 1996/1997 and 1997/1998, the embryonic development of Natator depressus was investigated in the laboratory. Eggs were incubated under different thermal and hydric conditions on vermiculite substrates. The thermal environment between 26 and 32 C significantly influenced the water exchange of eggs, incubation duration, nutrient mobilization of embryos, and the size, tissue hydration, and energy reserves of hatchlings. Hatchlings produced at 26 C and 29 C were larger but had lower energy reserves than those produced at 32 C. The influence of the hydric environment depended greatly on the range of substrate water potentials used in experiments. Nutrient mobilization of embryos and the size and energy reserves of hatchlings were dependent on total egg water exchange over the range of 2% gain to 29% loss (at approximately −180 to −3500 kPa incubation substrates) of initial egg mass but independent within the narrower range of 6% gain to 19% loss (at approximately −200 to −650 kPa substrates). Hatching was affected only when eggs lost more than 21% of their initial egg mass (at approximately −1300 kPa). A significant effect of clutch on the morphological and physiological aspects of developing embryos indicated that genetic/maternal factors influenced these traits. Natator depressus eggs seem to be laid with sufficient water reserves for successful embryonic growth and development. In most natural circumstances, this would make them independent of supplementary water from the environment.

Twelve new species of Eustomias (Dinematochirus) are described from the Indo-Pacific, and new specimens of Eustomias similis, a species previously known from only the holotype, are reported. All have two pectoral fin rays and relatively short barbels with pigmented stems; all but one have a branch or branches off the barbel stem. In addition, several Indo-Pacific specimens with two pectoral fin rays and very rudimentary branches off the barbel stem are informally described as forms of uncertain status. One of the new species occurs throughout the Indo-Pacific and in the southeastern Atlantic. Three others occur in both the north and south Pacific and another in equatorial waters of the western Pacific and Indian Oceans. The remainder appear to have relatively restricted ranges in the Pacific. With these new species, the genus Eustomias now includes 113 species, and the subgenus Dinematochirus 40 species plus several forms of uncertain status. Within Dinematochirus, 14 species are known only from the Atlantic, 19 only from the Indo-Pacific, and seven from both. A key to the species or species groups of the subgenus is provided.

A new species of plethodontid salamander is one of several large black species found in the Cordillera Talamanca-Barú of Panamá and Costa Rica. Bolitoglossa anthracina sp. nov. differs from others in this group in having a very large number of maxillary teeth and a moderate number of vomerine teeth.

To date, about 330 currently recognized species have been described from the haplochromine cichlid species flock endemic to Lake Malaŵi, Africa. Several hundred additional species await taxonomic treatment. A new species from this flock belonging to the genus Otopharynx is described from the deep waters of Lake Malaŵi. This species (known from only two demersal trawls made at different localities in water 78–135 m deep) is characterized by the presence of three distinct spots that do not extend to the dorsum and by moderately stout, bicuspid oral jaw teeth in outer series, placing it in the genus Otopharynx. It is a relatively deep-bodied member of this genus that differs from all other three-spotted cichlids by its fleshy, lobed lips. The greatly hypertrophied lips in this species may serve a sensory function by acting as an enlarged substrate for the expression of numerous taste buds in a peri-oral field. Additional characters are presented that distinguish this new species from its congeners. The genus Otopharynx is not defined on the basis of synapomorphies and is likely an artificial group. Nevertheless, it is a recognizable taxon that, for the time being, serves a useful purpose in organizing members of an exceedingly complex species flock, the systematics of which is far from complete.

The vertical organization and spatial variation of the main features of the retina of juvenile loggerhead sea turtles (Caretta caretta) were studied. Eyes were sectioned into 5-μm slices and examined using light microscopy techniques. Within each section, photoreceptor cells and ganglion cells were identified and counted. The topographical organization of cells along the retina was examined for the presence of an area centralis. The results show that the basic organization of the loggerhead retina closely follows the general vertebrate model. The retina is duplex in nature, containing both cone and rod cells throughout the photoreceptor layer. Moreover, the organization of the neural layers indicates that this eye is adapted for both high spatial resolution and low light sensitivity. A higher concentration of both cone photoreceptor cells and ganglion cells occurs dorsal to the equator of the eye, and their numbers are positively correlated. These findings suggest that loggerhead sea turtles possess a horizontal streak in the dorsal region of the retina, an attribute that could be beneficial for the loggerhead's benthic lifestyle.

A new species of Jenynsia from southern Brazil is described. Jenynsia weitzmani n. sp. from the rio Pinheiros drainage in Santa Catarina state is diagnosed by a single dark midlateral stripe, absence of associated dark dorsolateral or ventrolateral stripes or blotches in adults, a terminal to slightly oblique mouth, and absence of the first mandibular-canal pore (pore W). A phylogenetic analysis of primarily osteological data supported the new species as sister to a group composed of J. eirmostigma and J. eigenmanni within the subgenus Plesiojenynsia. A key to Jenynsia species is provided.

Recent reptile collections from southwestern Cameroon contain four specimens referable to Atheris subocularis Fischer, currently considered a synonym of Atheris squamigera (Hallowell), and previously known only from the holotype collected prior to 1888. Phylogenetic analysis of a 647 bp DNA fragment of the mitochondrial cytochrome b gene indicates that A. subocularis forms a monophyletic group. Based on this analysis and a suite of morphological characters that readily differentiate A. subocularis from its congeners, we resurrect A. subocularis Fischer from the synonymy of A. squamigera (Hallowell). Female A. subocularis remain unknown, and the distribution of this taxon lies completely within that of its closest relative, A. squamigera. We provide taxonomic accounts for A. subocularis and A. squamigera in the area of sympatry and discuss evolutionary hypotheses for the presence of A. subocularis.

A new species is described from the Pacific coast of Colombia. It differs from its congeners by having a shorter disc and a greater number of vertebrae. This brings the number of species in the genus Tomicodon to 15, 13 of them in the eastern Pacific and two in the western Atlantic.

We used 11 samples comprising 224 specimens collected between 1966 and 1999 in Chihuahua, México, and Texas to clarify aspects of color pattern and meristic variation in the notoriously difficult gonochoristic Cnemidophorus gularis-scalaris-septemvittatus complex which is characterized by enlarged mesoptychial scales and enlarged and platelike postantebrachial scales. We allocated populations represented in all SEPT-CMX samples except SEPT-CMX5 from northeastern Chihuahua to Cnemidophorus gularis septemvittatus Cope, 1892, type locality Marfa, Presidio County, Texas, represented by sample SEPT-TUS1. This allocation adds 28 newly discovered sites in Chihuahua to the single valid record previously known for the taxon in that state. Our study revealed that three taxonomically distinct forms, one in Trans-Pecos Texas east of Alamito Creek, Presidio County, and another in southern Coahuila, México (both beyond the scope of this study), were included in septemvittatus in a 1962 taxonomic revision. Clarification of the distribution and variation of C. g. septemvittatus in Chihuahua sets the stage for further systematic studies. Whiptail lizards in our SCAL-CMX samples from Chihuahua, for which only the name Cnemidophorus gularis scalaris Cope, 1892, is available, represent two forms distinguishable from each other and from C. g. septemvittatus on the basis of color patterns that remain distinct through ontogeny. Further sampling of Cnemidophorus populations in Chihuahua will be required to fully resolve the scalaris problem.

Early life histories of stream fishes are thought to influence dispersal biology and have potentially important consequences for gene flow. Documenting links of life history, larval dispersal, and gene flow is difficult because larvae of closely related species often cannot be confidently identified. In this study, field-caught darter larvae were identified to species by screening individuals for single-stranded conformational polymorphisms (SSCPs) in the control region of the mitochondrial (mt) DNA. A larval transport index (T) was compared among eight coexisting species of darters and tested for associations with adult life-history patterns and gene flow. Comparative analysis indicated that larval transport tendency was negatively associated with egg size, a result consistent with previous laboratory studies. Current velocity was also related to larval transport patterns. Etheostoma zonale larvae were more abundant than expected in high-flow habitats, whereas Etheostoma caeruleum larvae were most abundant in slow-flowing habitats, suggesting that larval fish dispersal and distribution patterns can differ greatly among closely related and ecologically similar species. Larval transport index values and gene flow were not significantly related.

We examined phylogenetic relationships among the Namib day geckos (genus Rhoptropus) using DNA sequence data from the mitochondrial cytochrome b (cytb) and 16S ribosomal RNA genes. Maximum-parsimony analysis of the cytb, 16S, and combined (cytb/16S) datasets each recovered an identical single most-parsimonious tree, revealing two well-supported clades: (1) Rhoptropus afer Rhoptropus bradfieldi ssp and (2) Rhoptropus boultoni (Rhoptropus barnardi Rhoptropus biporosus). Maximum-likelihood analysis identified the same two species groups and corroborated patterns of relationship within respective parsimony clades. Moreover, the mitochondrial DNA trees were congruent with parsimony trees derived from morphological and allozymic characters. Congruence observed among these different data offers strong evidence for our molecular phylogeny of Rhoptropus, bringing taxonomic stability to a genus whose species-level relationships were widely debated throughout the last century.

Despite the importance of sharks to marine ecosystems as top predators and growing concern over the conservation status of many shark species, surprisingly little is known about many aspects of their reproduction patterns and life history. Better knowledge of breeding biology and reproductive parameters will be important for designing appropriate management plans to protect dwindling populations of sharks. Here, we report new information regarding the mating system and reproductive cycle of a large coastal shark, the lemon shark Negaprion brevirostris, revealed through field observations and genetic analyses of an adult female and her offspring. Our findings demonstrate that this female exhibited philopatry to a nursery ground in Bimini, Bahamas, where she returned to give birth in both 1996 and 1998. Genetic analyses using DNA microsatellite loci developed for lemon sharks provided the first demonstration of polygamous mating and multiple paternity in a carcharhinid shark; at least three males had sired the litter she delivered in 1998.

Movement ecology and seasonal distribution of mountain yellow-legged frogs (Rana muscosa) in Dusy Basin (3470 m), Kings Canyon National Park, California, were characterized using passive integrated transponder (PIT) surveys and visual encounter surveys. We individually PIT-tagged 500 frogs during the summers of 1997 and 1998 and monitored these individuals during seven recapture surveys in 1997 and 15 recapture surveys in 1998 from the time they emerged from overwintering in July until the lakes froze for the winter in October. Probability of movement between lakes was associated with abundance of Hyla regilla larvae in the different lakes of origin, activity of the frogs (overwintering, breeding, feeding), and time of year. Overland movements exceeding 66 m were observed in 17% of the tagged frogs. Movement between lakes 1 km apart was detected. Site fidelity from 1997 to 1998 was high, and 97% of the tagged frogs recaptured in October of both years were found in the same overwintering lakes. Frogs were more narrowly distributed in spring and fall than in summer. Summer frog densities (number per meter of shoreline) were positively related to water temperature, air temperature, maximum lake depth, and presence of H. regilla larvae and negatively related to presence of trout. Mountain yellow-legged frogs use a range of aquatic sites throughout their activity period, and basins with a variety of deep lakes and shallow ponds may be the most appropriate reserves for this declining species.

Salmon sharks, Lamna ditropis, occur only in the North Pacific Ocean. These large sharks can grow to 250 cm total length and weigh 220 kg. They are endothermic, and previous investigators reported red muscle temperatures of 8–11 C above ambient water temperature. We recorded red muscle temperatures up to 15.6 C above ambient, along with additional muscle and organ temperatures.

Mitochondrial control region DNA sequence data were examined to determine levels and patterns of variation in 36 striped mud turtles, Kinosternon baurii, from 10 geographic locations across the species' range. Levels of sequence divergence were low, and 20 variable sites defined 18 haplotypes. Although unique haplotypes were found at most locations, several haplotypes were distributed rangewide. In particular, the putatively isolated population of the lower Florida Keys did not significantly differ genetically from the upper Florida Keys or mainland populations. Based on our analysis of 415 bp, the lower Florida Keys population either is not isolated or is very recently isolated from the remainder of the range. The lower Florida Keys population is classified as endangered by the Florida Fish and Wildlife Conservation Commission and extirpation of this population through loss of habitat seems likely. Efforts to protect suitable habitat for K. baurii, however, may increase the risk of extinction of other endangered species, such as the Key deer (Odocoileus virginianus clavium).

The redfin darter, Etheostoma whipplei (Percidae: subgenus Oligocephalus) has been the subject of several taxonomic treatments over the past 50 years. At the present, two subspecies are recognized: Etheostoma whipplei whipplei in the Ozark and Ouachita Highlands and Etheostoma whipplei artesiae on the Gulf Coastal Plain. We examined variation in meristics and pigmentation to assess the distinctiveness of eastern populations of E. w. artesiae. The results indicated that E. w. artesiae differs significantly from E. w. whipplei in meristics and features of male breeding pigmentation. We conclude that all populations currently recognized as E. w. artesiae should be elevated to full species status.

This paper reports the physical and biological nest parameters of loggerhead turtle (Caretta caretta) nests on northern Cyprus that predispose individual nests to infestation. All data were collected between June and September 1997, and data were analyzed using generalized linear models. The final model explained 66.5% of the total deviance, and the most significant factor was the depth to the egg chamber (deviance = 63.86, P < 0.0001). The implications of these results are discussed, and recommendations for future work are proposed.

Lepidomeda vittata (the Little Colorado River spinedace) is a cyprinid fish native to the Little Colorado River in Arizona. Mitochondrial DNA and allozymes were used to determine patterns of genetic variation in remaining populations of L. vittata. The pattern of variation observed indicated that genetic diversity was low, but population structure was high because of partitioning of genotypes among samples. Similarity of genotypes suggest current populations are relics from a single, large population that was one continuously distributed throughout the LCR drainage. Patterns of variation were consistent with decreases in population size; however, because of low levels of variation, it was impossible to determine whether the decline occurred during the past century or a larger time scales.

The recent collection of 12 specimens of Typhlops from northwestern Honduras demonstrates that Typhlops stadelmani is a valid species of wormsnake. Thus, Typhlops stadelmani is removed from the synonymy of Typhlops tenuis. A taxonomic synopsis of the newly defined T. stadelmani is provided.

The determinants of male reproductive success in natural populations have not been measured for any fundulid species in North America. In this study, spawnings, courtship of females, and aggression toward other males, females, and heterospecifics were recorded during daylight hours in a natural population of bluefin killifish, Lucania goodei. Three main findings emerge. First, spawning success is correlated with male aggression toward other males and with male courtship of females, indicating that both male/male competition and female choice are likely to be operating. This result implies that both male/male competition and female choice must be considered in studies of sexual selection (as opposed to dichtomous choice tests, which preclude male/male competition). Second, males exhibited substantial levels of aggression toward both nonbreeding females and heterospecifics. Males may be guarding eggs, guarding food items, or trying to keep an open area around them so that they can be seen by gravid females. Third, a polymorphism is present where males had either yellow or red anal fins. Males of both morphs were in breeding condition and spawned with females. Potential mechanisms for the maintenance of the polymorphism are discussed.

By using food rations and thyroxine supplements, I manipulated the growth and differentiation of tadpoles of the toad Bufo americanus to test the hypothesis that the plasticity in metamorphic timing can be lost. A significant food effect indicated that tadpoles that grew rapidly during the middle period of the experiment metamorphosed earlier than slow-growing tadpoles. The changes in growth induced early and late in this experiment did not influence metamorphic timing. There was a significant thyroxine effect: all tadpoles treated with thyroxine metamorphosed early. All thyroxine-treated tadpoles metamorphosed at the same time, indicating that differentiation at the time of thyroxine supplementation was independent of growth rate. A food-by-thyroxine interaction provided evidence that the growth rate/differentiation antagonism may have been active at least during the middle of the experiment. This suggests that the growth rate/differentiation antagonism is decoupled or overridden during later stages of larval development. This result implies limits to metamorphic plasticity and is consistent with a fixed-rate model of amphibian metamorphosis.

I examined the effects of low-tide timing on tidepool use by two southern California fishes, Clinocottus analis and Girella nigricans. Abundance of these fishes in middle and upper intertidal pools was higher when low tides occurred at night or in the early morning (4.4–9.7 fish per pool) than in the afternoon (1.3–3.4 fish per pool). Mean fish size was also higher during nighttime low tides than daytime low tides. Tidepools higher in the intertidal zone generally displayed greater differences in fish abundance between early morning and afternoon low tides than lower pools. In addition, these upper tidepools reached higher temperatures during afternoon low tides (up to 30 C) than lower tidepools, often exceeding or nearing the preferred and lethal maximum temperatures reported for the two study species. Diel vertical habitat shifts by middle and upper tidepool fishes indicate that their partitioning of rocky intertidal habitat occurs on short-term temporal as well as spatial scales.

Pacific electric rays (n = 198) were collected from central and southern California from July 1994 through January 1996 for studies on their age and growth, reproduction, and demography. Whole vertebral centra with graphite microtopography band enhancement were used for ageing. Average percent error and percent error were 6.5% and 4.9% among readings. Maximum age was an estimated 16 yr. The von Bertalanffy growth model provided the best fit and predicted an asymptotic total length of 1372 mm for females and 921 mm for males, and K was estimated to be 0.073 for females and 0.137 for males. Female and male reproductive status was determined using two and three criteria, respectively. Median total length-at-maturity, determined using a logistic response function, was 645 mm (age estimate, 6 yr) for males and 731 mm TL (age estimate, 9 yr) for females. Fecundity of one female was estimated at approximately 17 young per litter. Time of parturition could not to be determined. Instantaneous mortality estimates ranged from 0.096–0.277, depending on longevity estimates. Best age-based demographic analyses indicate that the Pacific electric ray population has a net reproductive rate per generation of 2.6–8.9, a generation time of 11.2–13.0 yr, instantaneous rates of change of 0.09–0.18, and finite rates of change of 1.09–1.20.

Recent studies have documented the occurrence of the nonindigenous swim bladder nematode parasite (Anguillicola crassus) in American eels (Anguilla rostrata) from Chesapeake Bay and Hudson River drainages. The parasite was originally discovered in a single American eel captured in Winyah Bay, South Carolina, in 1995. We examined eels from all major coastal rivers in North Carolina and recorded prevalence and mean intensity of infection. A total of 1111 eels were captured. Overall 52% were infected (prevalence ranged from 26–100% among rivers), and there were 1–53 nematodes per infected individual (mean intensity = 3.9). The condition of infected eels was not significantly different from that of uninfected eels; however, we found a significant positive relationship between mean intensity of infection and eel size. The infection rate of North Carolina eels was substantially higher than that reported in Chesapeake (10–29%) and Hudson River (0–12%) collections. The high infection rates we observed could be related to increased warm water periods in southern rivers or the fact that this exotic may have been introduced earlier in southern rivers than in northern ones.

Weakfish Cynoscion regalis and striped cusk-eels Ophidion marginatum both produce sounds, but there has been confusion in the literature on a particular sound, the “chatter.” It has been stated that this sound is produced by weakfish using their pharyngeal teeth. Striped cusk-eels make a similar sound (but not identified in the literature as a chatter) using sonic muscles associated with the swim bladder and vertebral components. The striped cusk-eel identifications were based on captive fish sound recordings, whereas the weakfish identifications were based on recordings made in situ where weakfish were visually observed but other sound-producing organisms could have been present. Based on new signal analysis of striped cusk-eel sounds made in captivity, we identify that species as the source of the chatter sound in our field recordings. The dominant frequency of the sounds increased while the pulse period decreased over the temperature range 18.0–27.5 C. The acoustic characteristics presented here will aid researchers in their identification of these sounds.

Chromosomes of Novumbra hubbsi were analyzed by Giemsa staining, C-banding, silver staining, CMA₃ fluorescence and fluorescence in situ hybridization (FISH). Diploid chromosome number of 2n = 48 was confirmed. The karyotype consists of two pairs of metacentric, five pairs of submetacentric, seven pairs of subtelocentric, and 10 pairs of acrocentric chromosomes (FN = 62). Nucleolar organizer regions are situated in the telomeric regions of the shorter arms of the largest and smallest subtelocentric pairs. Four additional CMA3-positive (but silver negative) sites also are present. Results of FISH (rDNA probe) suggest that all CMA₃-positive sites represent rDNA cistrons. C-positive blocks of heterochromatin are situated primarily in the short arms of biarmed chromosomes, providing a distinct banding pattern for most chromosomes. The karyotype of N. hubbsi may be derived from that of a hypothetical esocoid ancestor (with 2n = 48, FN = 48) by pericentromeric inversions and amplifications of NOR sites. The karyotype of N. hubbsi may link the simple karyotype of such ancestor with the unusual karyotype of Dallia pectoralis. Novumbra and Dallia may be more closely related to one another than either is to Umbra. Extant umbrid species cytotaxonomically may represent two distinct lineages, which differ by the type of karyotype differentiation: the polyploid/fusion branch that includes three species of the genus Umbra and an inversion/fission branch that includes N. hubbsi and one species (and possibly all three) of Dallia.

Cytogenetic data obtained for Serrasalmus rhombeus revealed two cytotypes (cytotype 1 and cytotype 2) at four sampling sites. Cytotype 1 consists of 2n = 60, 20M 24SM 6ST 10A and was detected in specimens from Negro River (Anavilhanas Islands), Solimões River (Camaleão Lake), confluence of Negro and Solimões Rivers (Catalão Lake), and Uatumã River. Cytotype 2 consists of 2n = 58, 22M 24SM 2ST 10A and was detected in specimens from Catalão and Camaleão Lakes. In Cytotype 2, the first chromosome pair was almost twice the size of second pair, and the constitutive heterochromatin pattern of each cytotype is distinct. The two cytotypes occurred sympatrically at Catalão and Camaleão Lakes, and no intermediates between the cytotypes were detected, suggesting each cytotype represents a different fish species.

Evidence is presented that the cirrhitid fish Amblycirrhitus indicus Fowler, 1938, a new name for the preoccupied Cirrhites fasciatus Cuvier, 1829, is the Atlantic Amblycirrhitus pinos (Mowbray, 1927). Cuvier's type locality of India is regarded as a probable error.