To assess patterns of geographic variation in the wide-ranging North American catostomid genus Cycleptus, 23 specimens were obtained from six locations among four drainage systems that exit into the Gulf of Mexico. Starch gel electrophoresis was used to compare gene products of 47 loci. A contingency chi-square test showed that the 23 samples did not come from a single, random-breeding population. Tests using exact probabilities showed that all samples from within each of the four drainage systems were in agreement with Hardy-Weinberg equilibrium expectations. Pairwise combinations showed that only two of the drainages could be combined and still result in equilibrium. Three allopatric genetic units are recognized: (1) Rio Grande drainage, (2) Mississippi drainage, and (3) the Alabama plus Pascagoula drainages. All three units can be distinguished by differences in allelic composition at certain enzymatic loci, levels of heterozygosity, number of genes expressed (some genes have been silenced in these allotetraploids), and perhaps a regulatory character involving mMdhp-A¹. We propose that these units be recognized as separate species. The Mississippi drainage population would retain the name Cycleptus elongatus (Lesueur). The Gulf Coast population has recently been described as Cycleptus meridionalis Burr and Mayden. The Rio Grande population awaits further analysis of morphological and molecular variation and a formal description.

We studied the growth and survival of wood frog, Rana sylvatica, larvae infected with the leech, Desserobdella picta, a common ectoparasite of amphibian larvae and adults. In a laboratory setting, we exposed wood frog tadpoles of different body sizes and environmental rearing conditions to 0–5 leeches to determine their direct and interactive effects on tadpole growth and survival. Increased parasite intensity was positively correlated with leech pathogenicity for all experimental conditions and resulted in dramatically lower larval growth rates and survival. Leech infection also contributed to significant interactions involving tadpole body size, rearing temperature, food level and population density. Leeches had a disproportionately greater effect on small tadpoles and tadpoles reared at lower temperatures, lower food levels, and higher population densities. This was particularly true for tadpoles infected by a single leech; tadpoles infected by two or more leeches all died shortly after being infected regardless of body size or environmental rearing conditions. Our results also demonstrated that tadpoles were more likely to be infected by a single leech, even at high leech densities, indicating that interactive effects are likely to be important regardless of leech population size. Collectively, our results demonstrate that leeches have significant lethal and nonlethal effects on tadpole fitness traits. However, the magnitude of their impact on wood frog survival and population growth will depend on environmental factors and to a lesser degree on leech abundance.

The Bayou Pierre system in western Mississippi is currently experiencing extensive erosion, with pulses of erosion moving from lower to higher stream reaches (e.g., headcutting). This erosion has caused substantial changes to the system, including channel widening and deepening, general loss of downstream riffle habitats, and the creation of new riffle habitats in more upstream locations. We address the impact of the rapid and ongoing geomorphic changes on Etheostoma rubrum [bayou darter; a federally listed species (Threatened) endemic to Bayou Pierre] and associated, riffle-inhabiting species, including Etheostoma lynceum (brighteye darter), Noturus hildebrandi (least madtom), Cyprinella camura (bluntface shiner), and Etheostoma whipplei (redfin darter). We first characterize stream reaches based on geologic and geomorphic data and then estimate population densities of riffle-inhabiting fishes in each geomorphically homogeneous stream reach. To assess trends in relative abundances of all riffle-inhabiting fishes and population sizes of numerically dominant riffle-inhabiting fishes, we compare relative abundances and densities from 1993–1994 with those from 1986–1988. There is an overall trend for recent erosion to occur in the upper reaches of the Bayou Pierre system, with lower reaches characterized by later, recovery, stages. Between 1940 and 1994, the point of active headcutting moved over 7 km upstream at rates of 48–750 m/yr. The relative abundances of E. rubrum and associated riffle-inhabiting fishes have not changed significantly from 1986–1994. Combined densities of all riffle-inhabiting fishes, as well as densities of three of the four most abundant species (E. rubrum, E. lynceum, N. hildebrandi), have also remained temporally stable. Overall, densities of riffle-inhabiting fishes averaged 6.7 ± 0.2/m². The density of all riffle-inhabiting fishes varied across geomorphic stages, as did the densities of E. rubrum, E. lynceum, and N. hildebrandi, with higher fish numbers in areas of active or recent erosion. This has resulted in a general pattern of greater fish densities in more upstream areas. Ultimate factors responsible for the rapid headcutting are located downstream of currently affected reaches in Bayou Pierre and the Mississippi River. These potentially include natural meander cut-offs, channel avulsion, channelization, and instream gravel mining. Thus, river-management decisions impacting areas spatially distant from the study area appear to have resulted in major local changes.

Adult females of the toad Bufo marinus significantly exceed adult males in snout–vent length (SVL), but at any SVL, adult males greatly exceed adult females in the robustness of the forelimbs. Secondary sexual shape dimorphism results from greater size and mass of the skeletal elements of males, and especially from their hypertrophied forelimb musculature. The dimorphism is particularly pronounced for those elements of the musculo-skeletal apparatus known or presumed to function in amplexus, and this intersexual difference is hypothesized to have evolved under sexual selection. Reproductively successful males (those found in amplexus) significantly exceed unsuccessful males (calling, nonamplectant males) in SVL, an example of the large-male mating advantage commonly seen in anuran amphibians. However, independent of body size, amplectant males significantly exceed nonamplectant males in forelimb muscle mass, suggesting that it is not large body size per se that confers a mating advantage but rather the robustness of the forelimbs allows males to retain a firm grip on the female in amplexus and, thus, to resist take overs by competing males in this explosively breeding species. The intrasexual component of Darwian sexual selection, expressed as male-male competition, is implicated in the evolution of this sexual dimorphism, but a role for female choice cannot be excluded. The results are consistent with the hypothesis that intersexual differences in forelimb muscle mass have evolved under sexual selection, and they suggest that, for males, selection favoring large forelimb muscle mass is operating still.

Diversification of threespine stickleback trophic morphology in relation to habitat has been studied extensively, but dentition has been ignored. Using samples of threespine stickleback from a range of habitats in the Pacific and Atlantic Basins, we characterize the morphology of individual teeth and their arrangement on the premaxilla. Although tooth morphology does not vary conspicuously, we observed striking differences in tooth arrangement between Pacific and Atlantic populations, significant variation among populations within basins, and pronounced sexual dimorphism in tooth number and arrangement within all populations from both basins.

The chytrid fungus Batrachochytrium dendrobatidis was originally reported in wild frog populations in Panama and Australia, and from captive frogs in the U.S. National Zoological Park (Washington, DC). This recently described fungus affects the keratinized epidermis of amphibians and has been implicated as a causative factor in the declines of frog populations. We report here the presence of B. dendrobatidis in larval and recently metamorphosed mountain yellow-legged frogs (Rana muscosa) in or near the Sierra Nevada Mountains of California, an area where declines have been documented in all five species of native anurans. Forty-one percent (158 of 387) of larval R. muscosa examined in the field with a hand lens and 18% (14 of 79) of preserved larvae had abnormalities of the oral disc. Twenty-eight larvae were collected from 10 sites where tadpoles had been observed with missing or abnormally keratinized mouthparts, and 24 of these were examined for infection. Sixty-seven percent (16 of 24) of these tadpoles were infected with B. dendrobatidis. Batrachochytrium dendrobatidis was cultured from both tadpoles and recent metamorphs from one of these sites. Tadpoles with mouthpart abnormalities or confirmed chytrid fungus infections were collected at 23 sites spanning a distance of > 440 km and an elevational range from 1658–3550 m. Life-history traits of R. muscosa may make this species particularly susceptible to infection by Batrachochytrium. We recommend that biologists examine tadpoles for oral disc abnormalities as a preliminary indication of chytridiomycosis. Further, we believe that biologists should take precautions to prevent spreading this and other amphibian diseases from one site to another.

The taxonomic status of Gerres longirostris (Lacepède, 1801), Gerres britannus (Lacepède, 1802), and Gerres poieti Cuvier, 1829, is examined. Gerres longirostris is considered a valid species and a senior synonym of G. britannus, G. poieti, and Gerres acinaces Bleeker, 1854a, and four other species (Gerres lineolatus Playfair, 1867, Gerres longicaudus Alleyne and Macleay, 1876, Gerres rueppellii Klunzinger, 1884, and Gerres darnleyense Ogilby, 1913). Gerres longirostris is redescribed, with designation of a neotype from Madagascar, Indian Ocean. Gerres oblongus Cuvier, 1830, is also confirmed as a valid species and a senior synonym of Gerres macrosoma Bleeker, 1854b, and Gerres gigas Günther, 1862. A lectotype is designated for G. oblongus and a neotype for G. macrosoma. Gerres longirostris and G. oblongus belong to the ”Gerres longirostris complex.” Gerres longirostris differs from G. oblongus in having a deeper body (mean 39% SL vs mean 33% SL in G. oblongus), fewer pored lateral line scales (43–46 vs 45–49), and a broad dark caudal fin posterior margin. Both species are widely distributed in the Indo-Pacific region.

Experimental elevation of plasma testosterone during the nonbreeding season has previously been shown to reduce the survivorship of male mountain spiny lizards, Sceloporus jarrovi. The reduction in survivorship results from energetic stress caused, in part, by reduced foraging behavior. This study examines proximate explanations for this decreased foraging behavior. In particular, do testosterone-treated males engage in more social behaviors at the expense of feeding? This question was tested by observing the behavior of hormonally manipulated males in a large indoor arena in which both social and prey stimuli were present. Males were tested with social stimuli present during the nonbreeding season (male intruders, sexually unreceptive females, or a combination of male and females) and with stimuli encountered only during the breeding season (sexually receptive females). Testosterone-implanted males ate significantly fewer prey when a sexually receptive female was present, but control males did not. However, a difference in feeding was not observed in any of the nonbreeding stimulus conditions in spite of consistent increases in social behaviors, such as display frequencies. These results indicate that, although high levels of testosterone increase some aspects of social behavior, they do not necessarily lead to decreased feeding in the nonbreeding season.

Species of the eelpout genus Lycodes with a lateral line configuration containing a complete ventral row of neuromasts and a mediolateral row from above the anal fin origin toward the caudal fin were reviewed. The 434 specimens examined belong to five species: Lycodes albolineatus Andriashev, 1955; Lycodes concolor Gill and Townsend, 1897; Lycodes pallidus Collett, 1878; Lycodes squamiventer Jensen, 1904; and Lycodes paamiuti n. sp. The new species is most closely related to L. pallidus and L. squamiventer and differs mainly in the larger pupil, shorter nostril tube, more anterior intercession of the dorsal fin (first ray associated with vertebra 4–5 (rarely 6) versus 6–9 (rarely 5) in L. pallidus and L. squamiventer). Lycodes paamiuti n. sp. is an Arctic species, occurring on continental slopes in Baffin Bay to the Norwegian Sea, in depths of 350–1300 m. Separation of L. squamiventer from L. pallidus was originally based mainly on the more dense squamation in L. squamiventer, and the validity of the species is here supported by differences in number and size of the pharyngobranchial teeth.

We compared 786 base pairs of cytochrome b mitochondrial DNA sequence to examine the evolutionary relationships among seven species belonging to three genera of Asian newts: Paramesotriton, Pachytriton, and Cynops. We find strong evidence supporting recognition of a clade for these genera. Although bootstrap support values are relatively low, both parsimony and likelihood analyses suggest that the species of Paramesotriton sampled form a monophyletic group with Paramesotriton caudopunctatus basal to the other three species. Cynops appears to be paraphyletic, with Pachytriton and Paramesotriton being more closely related to Cynops pyrrhogaster than to Cynops cyanurus. Pachytriton and Paramesotriton exhibit some morphological similarities and have more specialized breeding habits and environmental requirements than Cynops, suggesting that they shared an evolutionary history before diverging. Our morphological investigations corroborate previous studies that suggested Cynops is the most generalized representative of the clade and that it retains several ancestral character states.

A new species of Aspidoras is described from the upper rio Itiquira and the upper rio Taquari, rio Paraguai basin, and represents the first record of the genus from this river system. The new species differs from its congeners by the following unique features: infraorbitals and preopercle covered by skin; nuchal plate reduced and covered by skin; and lateral line absent from body plates posterior to the two small lateral line ossicles. The new species exhibits the greatest body size observed for an Aspidoras species. The occurence of Aspidoras in tributaries of the rio Paraguai basin extends the range of the genus further southwest than previously known, encompassing most of the river basins that drain the Brazilian Shield.

We examined chemical communication and behavioral interactions between juvenile Ambystoma opacum and Ambystoma talpoideum (Caudata: Ambystomatidae) in two laboratory experiments. In experiment 1, we investigated olfactory communication in both species by exposing salamanders to (1) nonmarked substrates (control), (2) self-marked substrates, (3) conspecific-marked substrates, and (4) heterospecific-marked substrates. Juvenile A. opacum spent significantly more time on the self-marked soil substrate when compared to the control and also spent significantly more time at the edge of the experimental chamber in the conspecific treatment when compared to the control. In experiment 2, we examined behavioral interactions between paired resident salamanders when a limited resource (i.e., one cover object) was present. Encounters were between (1) a resident salamander and a surrogate (control), (2) conspecific residents, and (3) heterospecific residents. Neither juvenile A. opacum nor A. talpoideum significantly altered their behaviors in response to different types of cohabitors. Although A. opacum were observed biting other salamanders on rare occasions, neither juvenile A. opacum nor A. talpoideum significantly altered their behaviors in response to different types of opponents. These results indicate that chemical communication and behavioral interactions may not be important for spacing behavior of recently metamorphosed A. opacum and A. talpoideum.

ENGLISH:

Eptatretus wayuu and Quadratus ancon are described from the Caribbean coast of Colombia at depths of 300–306 m and 470–488 m, respectively. Eptatretus wayuu is a five-gilled species with only two slime pores on one side of the body (slime pores present only on median side of first two left gill apertures and first and last or first two right gill apertures) and an anteriorly branched ventral aorta. Quadratus ancon exhibits the diagnostic characteristics for Quadratus (nonlinear and crowded gill apertures). Quadratus ancon is a six-gilled species with gill apertures closely and irregularly crowded, the last left efferent branchial duct not joining the pharyngocutaneous duct, more cusps, higher prebranchial and total slime pore counts than congeners. The new species are compared among other geographically and morphological proximate Eptatretus, Paramyxine, and Quadratus species. Quadratus ancon is the first species of this genus to be reported from the Caribbean Sea.

SPANISH:

Se describe a Eptatretus wayuu y Quadratus ancon a partir de los holotipos y un paratipo colectado en la costa Caribe colombiana a profundidades entre 300–306 m y 470–488 m, respectivamente. Eptatretus wayuu es una especie de cinco aberturas branquiales con su aorta ventral ramificada anteriormente. Quadratus ancon es una especie de seis aberturas branquiales estrechas e irregularmente amontonadas y el ultimo ducto branquial eferente izquierdo no unido al ducto faringocutaneo. Se les comparan con otras especies de Eptatretus y Paramyxine y/o Quadratus characteristicas similares descritas previamente por otros autores. Quadratus ancon es el primer Myxinido con aberturas branquiales amontonadas que se registra para el mar de las Antillas.

The Mexican Pacific lowlands garter snake, Thamnophis validus, is found in aquatic habitats on the Pacific coast of México from the states of Sonora to Guerrero and in the Cape Region of the Baja California peninsula. We characterized the diet of Thamnophis validus through examination of stomach contents of museum specimens and from literature records. The diet of T. validus consists almost entirely of fishes and larval and adult anurans. There is strong geographic variation in the diet: snakes from uplands of Baja California contained only anurans, whereas the majority of snakes from mainland México that contained prey had eaten fishes. Mainland snakes show a pronounced ontogenetic shift from feeding primarily on anurans to feeding primarily on fishes. When mainland snakes are divided into three size classes, the intermediate class shows the most generalized diet (i.e., the most even distribution between fishes and anurans). We suggest that this nonmonotonic relationship between predator size and the level of specialization may be relatively common in snakes. Prey mass and the variance in prey mass both increase with increasing predator size in T. validus, as is the case for many carnivorous animals. Thamnophis validus apparently differs from other aquatic garter snakes (T. atratus, T. couchii, T. hammondii, T. melanogaster, and T. rufipunctatus) in feeding heavily on adult anurans and in the common use of aquatic open-mouth searching behavior.

Two species of gerreid fishes have been confused under the name Gerres poieti Cuvier, 1829, a name originally assigned to the gerreid fish from Indonesia illustrated and named “ikan-poeti” in Renard, 1719. A year later, Cuvier published a description of Gerres poeti (incorrect subsequent spelling) based on a 150 mm SL fish from Mahé, southwest coast of India, which he stated was the same species as Renard's ikan poeti. Iwatsuki et al. recognized Renard's fish as Gerres longirostris (Lacepède, 1801); consequently, Gerres poieti Cuvier, 1829, becomes a synonym of G. longirostris. Despite several discrepancies between Cuvier's description of the Indian fish and Renard's illustration of ikan poeti, the name poieti (or poeti) has been used as the valid name for both G. longirostris and an undescribed species from the southwest coast of India. The Indian species misidentified as Gerres poeti (sic) by Cuvier in 1830 is here described as a new species, Gerres phaiya, of the Gerres erythrourus species complex. This new species is characterized by an exceptionally robust second anal fin spine (ratio of greatest width of second spine/greatest width of third spine = 1.5–2.4), three supraneural bones (0/0 0/2/), dorsal fin with nine spines and 10 rays, 36–40 lateral line scales, four or 4.5 scales between fifth dorsal fin spine base and lateral line, 12–15 total gill rakers on first gill arch, caudal fin lobes rounded posteriorly, body depth 46–52% SL, and the silvery body often with 6–10 dusky vertical bars. Additional data are given for G. erythrourus (Bloch, 1791).

Among-individual variation in locomotor performance can have important fitness consequences. In turtles, the duration of the righting response, or the time it takes an individual to return to a prone position after being placed on its carapace, is a trait with possible ecological significance. In this study, we quantified righting response time for 21 juvenile snapping turtles (Chelydra serpentina) at three testing temperatures and for an additional 254 juvenile snapping turtles representing 24 clutches at 30 C, and examined effects of testing temperature, egg size, egg incubation temperature, and clutch identity on among-individual variation in righting response. Righting response times ranged from 1 sec to over 900 sec. Testing temperature and clutch identity affected righting response time, whereas egg incubation temperature and egg mass did not. Righting response time was consistent across individuals and clutches. Our findings suggest that investigators should include clutch as an important variable in behavioral studies of turtles.

Section editor: R. E. Gattern Jr

ENGLISH:

A new Moenkhausia species is described from the middle rio Negro of Brazil. This species shares with Moenkhausia oligolepis, Moenkhausia sanctaefilomenae, and Moenkhausia pyrophthalma a reticulate body coloration and a red pigmentation on the dorsal margin of the eye. It can be distinguished from those species by the presence of a distinctive stripe on the caudal peduncle, a uniform anterior humeral blotch, and meristic and morphometric data. Priocharax ariel, Serrabrycon magoi, Microsternarchus fimbripinnus, and Acestridium martini are recorded for the first time from the middle rio Negro in Brazil.

SPANISH:

Uma espécie nova de Moenkhausia é descrita do médio rio Negro no Brasil. Esta espécie compartilha com Moenkhausia oligolepis, Moenkhausia sanctaefilomenae e Moenkhausia pyrophthalma um padrão de colorido reticulado e a pigmentação vermelha na margem dorsal do olho. Distingui-se destas espécies pela presença de uma faixa perspícua no pedúnculo caudal, uma mancha umeral anterior uniforme e por dados merísticos e morfométricos. Priocharax ariel, Serrabrycon magoi, Microsternarchus fimbripinnus e Acestridium martini são registrados pela primeira vez no médio rio Negro no Brasil.

I described the advertisement call of Physalaemus enesefae in the time and spectral domains and analyzed the relationship between male body size, mass and condition, and call characteristics. I also estimated among-male and within-male variation in seven call traits and their repeatabilities. For the population under study, male calls were 720 ms long, had a dominant frequency of 898 Hz, and were repeated at 3.8-sec intervals, on average. Weak but significant correlations existed between male mass and three call traits: dominant frequency, initial frequency, and final frequency of the call. There was ample among-male variation in all call traits analyzed. In relation to within-male variation, the intercall interval had the highest coefficients of variation, and the initial and the final frequency of the call had the lowest. All the call traits analyzed were static except for intercall interval, which was dynamic. Intercall interval had the lowest repeatability of all call traits analyzed. Thus, call traits with the lowest within-male variation had the highest repeatabilities and vice versa. Individual variation in call traits and high repeatabilities set the stage for the evolution of most call traits. Selection on intercall interval, however, might have a limited evolutionary effect as a consequence of its low repeatability.

A new species of Chromogobius is described based on material collected from the Canary Islands (eastern Atlantic). Chromogobius britoi n. sp. differs from the other species in the genus in possessing all ctenoid scales on the trunk, fewer scales in the lateral series, a reduced number of sensory papillae in the vertical rows under the eye (rows 1–5), and a generally deeper depth preference. The cheek myology of gobioid fishes includes characters of possible phylogenetic significance and is generally overlooked in systematic studies; it is included here along with a discussion of possible relationships.

A new species, Poecilopsetta dorsialta, from the Philippines is described from seven specimens (one female and six males). This species is characterized by a long first dorsal fin ray and fewer lateral line scales. It also has a long ocular side pelvic fin.

Polydactylus longipes n. sp. is described on the basis of three specimens collected from Mindanao Island, Philippines. The species is uniquely distinguished from other Polydactylus species with six pectoral filaments by the length of the latter, the uppermost two extending beyond the midpoint of the caudal peduncle. The new species is further distinguished from other Polydactylus species by the following combination of characters: 13 unbranched pectoral fin rays, six pectoral filaments, 54 or 55 pored lateral line scales, six and 11 scale rows above and below the lateral line, respectively, 31 or 32 gill rakers, vomerine teeth present and grayish-black body.

We used four pairs of polymerase chain reaction primers complementary to the ends of interspersed nuclear elements to amplify markers that differentiate bull trout (Salvelinus confluentus) and brook trout (S. fontinalis) and allow the identification of hybrids between these species. We identified 21 DNA fragments in bull trout that are absent from brook trout and 13 DNA fragments in brook trout that are absent from bull trout. This PCR-based test gave results that are consistent with results from allozyme loci known to be diagnostic for these species. Similar interspersed elements are found in all eukaryotes, making this a potentially useful technique for species identification in many taxa.

Using mitochondrial cytochrome b and 16s gene sequences, we examined the genetic diversity of eastern Batrachuperus distributed in China along the eastern slopes of the Tibet Plateau. The group showed a moderate pairwise divergence compared to other salamander groups. The highest cytochrome b divergence is 10.07%. A phylogenetic analysis of the mitochondrial haplotypes revealed several evolutionarily independent lineages, including the Hongya and Pengxian populations of Batrachuperus tibetanus that probably represent undescribed species. The genetic divergence of Batrachuperus is clearly much higher than currently perceived. The distribution patterns of the mitochondrial haplotypes of the northwestern populations indicated that the dispersal or divergence of Batrachuperus might not be confined to river valleys, although all species in the genus are fully aquatic.

We measured the standard and postfeeding metabolic rates of a sedentary shark, the swellshark, Cephaloscyllium ventriosum (Scyliorhinidae). The average standard metabolic rate (SMR) of juvenile swellsharks (0.14–0.23 kg) was 44.3 ± 6.4 mg O₂ kg⁻¹ h⁻¹. Metabolic rate increased and reached a maximum approximately 9 h postfeeding. The maximum postfeeding metabolic rate averaged 2.3 times SMR, and the entire duration of the response was approximately 12 h. The overall pattern and magnitude of the postfeeding response is similar to those previously reported for the small-spotted catshark (Scyliorhinus canicula; Scyliorhinidae) and for many teleosts. The return to a prefeeding metabolic rate appears to be much more rapid in the swellshark than in the small-spotted catshark.

Section editor: R. E. Gatten Jr

Variability within the genus Phrynosoma in the occurrence of ocular-sinus blood-squirting, reportedly a defense used in canid encounters, is reviewed from the literature. Six species have been reported to squirt blood, and seven species remain unreported. Five of the latter species were tested in dog trials; one exhibited blood-squirting (Phrynosoma hernandesi), one exhibited precursor behaviors but failed to squirt blood (Phrynosoma ditmarsi), and three yielded negative results (Phrynosoma mcallii, Phrynosoma modestum, and Phrynosoma platyrhinos). Instances of blood-squirting in response to human encounters were collected and largely support the negative results for the three species P. mcallii, P. modestum, and P. platyrhinos. A phylogeny of blood-squirting and nonblood-squirting species is presented with blood-squirting being plesiomorphic in the genus and the synapomorphic condition of nonsquirting species being restricted to a single clade of P. mcallii-modestum-platyrhinos. The possibility of P. douglasii independently evolving an autapomorphic condition remains unresolved. Dog trials with 40 adult Phrynosoma cornutum were conducted to determine influences of body size and sex on squirt frequency and blood mass expelled, as well as to examine aspects of the potential physiological cost of the defense. In 153 trials, 85% of all lizards squirted in at least one trial, 82% squirted in more than one trial, and two lizards squirted daily over the seven-day trial period. Initial body mass positively correlated with the total number of squirts/individual (r² = 0.28; P < 0.001) and the number of days a lizard continued squirting (r² = 0.63; P < 0.01). Number of squirts/individual/day declined over the seven-day trial period (r² = 0.20; P < 0.05). Cumulative mass loss for individual lizards attributable to blood-squirting averaged 0.7 ± 0.8 g (2.0 ± 2.0% body mass), with a high of 2.8 g (6.8% body mass). In addition, juvenile P. cornutum and P. hernandesi were shown to squirt blood in dog trials, illustrating the early developmental onset of the behavior.

The large barbs of East Africa are well known for their morphological plasticity. Mitochondrial DNA sequences were compared for specimens of three distinctive barb morphotypes collected syntopically from the Genale River in southeastern Ethiopia. The “normal,” “lipped,” and “large-mouthed” morphotypes are putatively referable to Barbus gananensis. An analysis of molecular variance revealed that the lipped and normal morphotypes are not genetically distinct (ϕ_ST < 0.0001, P = 0.80) and that the group of large-mouthed haplotypes is significantly differentiated from a combined group of normal and lipped haplotypes (ϕ_ST = 0.54, P < 0.001). The evolutionary relationships among the haplotypes were assessed with phylogenetic and minimum-length spanning trees. The results of the phylogenetic and spanning tree analyses are consistent with the analysis of molecular variance. The normal and lipped morphotypes represent morphological variants of B. gananensis, and the large-mouthed morphotype represents a genetically distinctive undescribed species.

We used analyses based on surveys of > 1700 water bodies in a 100,000-ha area in the John Muir Wilderness (JMW) and Kings Canyon National Park (KCNP) to determine the influence of nonnative trout on the distribution and abundance of Hyla regilla in the High Sierra Nevada. At the landscape scale (JMW compared to KCNP), a negative relationship between trout and frogs in lakes was evident. In the JMW study area where trout are more abundant, only 7.2% of all water bodies contained H. regilla versus 26.6% in the KCNP study area. Also, the percentage of the total water body surface area containing H. regilla was 19.4 times higher in the KCNP study area than in the JMW study area. Hyla regilla were most abundant in portions of KCNP where the probability of finding lakes with trout is lowest and least abundant in the northern part of the JMW where the probability of finding lakes with trout is highest. At the water body scale, after accounting for the effects of all significant habitat and isolation variables, the odds of finding H. regilla in water bodies with no trout was 2.4 times greater than in water bodies with trout, and the expected number of H. regilla in water bodies with H. regilla and without trout was 3.7 times greater than in water bodies with both H. regilla and trout. Hyla regilla were significantly more likely to be found at the lower elevations (3000–3400 m) compared to higher elevations (3400–3800 m) and in shallow water bodies with high percentages of silt in near-shore habitats. Our study demonstrates a negative relationship between fish presence and H. regilla distribution and abundance in lakes and suggests that H. regilla has declined in portions of the High Sierra with high numbers of trout-containing lakes. It adds an additional native species to the mounting evidence of landscape-scale declines of native species resulting from the introduction of predatory fish.

Proper timing of the reproductive cycle to assure mate access is critical to optimizing success. We tested the importance of male presence on the progression of the female reproductive cycle in the blood python, Python curtus. Upon reaching sexual maturity, captive-born, individually raised virgin female snakes were housed with either a conspecific male or female. At the onset of the reproductive season (late autumn), all females initiated early follicular growth; however, only females housed with males initiated vitellogenesis, and these females ovulated and oviposited viable eggs. Females not housed with males showed arrested follicular development in that they maintained hydrated, nonvitellogenic follicles that underwent follicular regression after three months. The requirement for male presence prior to vitellogenesis is premature for fertilization but assures the female of a mate prior to mobilizing substantial energy stores into reproduction. Once an energy investment is made, females commit to completing the cycle.

Section editor: R. E. Gatten Jr

The advertisement call of Pelodytes ibericus (Anura: Pelodytidae) is composed of two distinct pulsed notes (A and B). A single A note is always emitted at the beginning of a call, and it may be followed by a sequence of 0–9 B notes. We studied the role of vocalizations in male-male competition by performing a playback experiment on naturally calling focal males by mimicking the effect of competing male calls with call bouts of different number of Bs. The A and B notes used as stimuli were standard natural calls selected through audiospectrogram correlations. Field tests were performed with a portable computer and interactive playback software. Males responded to stimuli by increasing call repetition rate (= decreasing intercall interval), pulses/note and note duration. Other static call parameters (frequency and number of pulses) did not increase and did not change linearly with the number of B notes in the stimulus. In addition, males did not increase the number of B notes in their calls, and the number of B notes/call was not correlated with the number of B notes in the stimulus. The biological significance of the repetition of the number of B notes remains unknown, but it does not appear to have a simple role in male-male competition.

A total of 1981 bp of the mitochondrial 16S rRNA, 12S rRNA and cytochrome b genes were analyzed in five boine and one pythonine snake species to determine phylogenetic relationships between Malagasy and Neotropical taxa included in the genus Boa. The obtained cladograms significantly grouped Boa constrictor with the Neotropical genera Eunectes and Epicrates, whereas the Malagasy species were the sister group of the clade of the three Neotropical taxa. Based on these results, Sanzinia and Acrantophis should be considered as valid generic names for the Malagasy boas. Their origin may be a result of a Cenozoic dispersal from Africa or Asia.