We present direct experimental evidence of maternal-to-embryo nutrient transfer in largespring gambusia, a species in which embryonic development was believed to depend solely on nutrients and energy sequestered in the egg prior to fertilization. Thirteen pregnant females were injected with tritiated leucine, and developing embryos of those individuals were assayed for radioactivity two hours postinjection. In eight females, one to all embryos in the developing brood showed significant uptake of labeled leucine. This finding suggests that matrotrophy may be an important maternal investment strategy for this species.

Currently, conservation efforts are devoted to determining the extent and the causes of the decline of many amphibian species worldwide. Human impacts frequently degrade amphibian habitat and have been implicated in many declines. Because genetic variance is critical in determining the persistence of a species in a changing environment, we examined the amount of genetic variability present in a single population for tolerance to an environmental stressor. We examined the amount of genetic variability among full- and half-sib families in a single population of southern leopard frogs (Rana sphenocephala) with respect to their tolerance to lethal concentrations of the agricultural chemical, carbaryl. Analysis of time-to-death data indicated significant differences among full-sib families and suggests a large amount of variability present in the responses to this environmental stressor. Significant differences in responses among half-sib families indicated that there is additive genetic variance. These data suggest that this population may have the ability to adapt to environmental stressors. It is possible that declines of amphibian populations in the western United States may be attributed to low genetic variability resulting from limited migration among populations and small population sizes.

Discontinuous variation in daily growth patterns suggests that there are alternative life-history tactics among males of a coastal fish species. Male dwarf perch are known to be mature and reproductively active at birth, exhibiting a high level of material and behavioral expenditure on breeding early in life. Males experience a substantial cost of reproduction in reduced early growth and survival relative to females. Through analysis of daily growth increments in otoliths, we showed that young-of-year males from two populations exhibit a polymorphism in daily growth patterns. A distinctive episode of narrow growth increments and slow growth punctuated the summertime growth record of some males, whereas increment widths were more uniform and growth was more rapid in other males. Discriminant function analysis revealed that features of the daily growth record varied discontinuously, falling into two distinct groups. Early-born males were more likely to exhibit the slow growth pattern, and late-born males were more likely to show the fast growth pattern. We interpret these results as indicating that late-born males, with relatively few opportunities for mating, defer reproductive effort and minimize the growth cost of reproduction. There is likely to be a strong selective advantage for early-season birth dates among males in these populations.

Extensive genetic variation has been documented throughout the range of the Two-lined salamander (Eurycea bislineata) species complex; however, a lack of fine-scale studies across putative species boundaries in this group has made it difficult to ascertain the amount of gene exchange that occurs between different genetic groups. We investigated patterns of gene exchange in populations from the Blue Ridge Mountains and adjacent Atlantic Slope, by analyzing allozyme variation along a transect that traverses a hypothesized contact zone between montane and lowland forms of the complex, E. wilderae and E. cirrigera. Geographically concordant transitions in allele frequencies at four allozyme loci indicate that a contact zone between these forms exists in the Savannah River drainage in the Piedmont of South Carolina. Variation in the PEP-B locus exhibits a broad cline that crosses the transition between the Blue Ridge and Piedmont physiographic provinces. A fixed difference at one locus (PK), nearly fixed differences at two other loci (AAT-1 and PEP-LA), and a Nei's genetic distance of 0.22 (D = 0.17–0.32) across the contact zone reflect an extended history of reduced gene exchange between these forms. The genetic data from the contact zone suggest that these montane and lowland forms are distinct species.

Most osteichthyans continuously replace their teeth throughout their lifetimes. Replacement teeth may develop in the soft tissue outside the bone to which they will attach (“extraosseous”) or in sockets within the bone (“intraosseous”) beneath their functional predecessor. This paper presents a systematic documentation of the position of developing replacement teeth in teleost fishes, based upon a literature review and examination of modern skeletal material. Plotting the distribution of this character on a cladogram of teleost phylogeny indicates that extraosseous development of replacement teeth is plesiomorphic. Intraosseous development, the derived state, has evolved in at least three clades: in branchial and palatal dentitions of the elopiform Albula; in oral dentitions of several characiforms; and in oral and/or pharyngeal dentitions of various acanthopterygians, especially many perciforms. Two interrelated changes are necessary for the evolution of this derived state: replacement teeth must move beneath their functional predecessors; and replacement teeth must be encased in bone. Intraosseous development of replacement teeth may affect the relation of the dermal and endochondral skeletons.

New specimens and a new analysis provide the basis for systematic revision of Central American caecilians. We recognize seven species in the genus Dermophis (oaxacae, mexicanus, gracilior, costaricense, glandulosus, parviceps, and occidentalis). Two species of Gymnopis (syntrema and multiplicata), three of Oscaecilia (osae, elongata, and ochrocephala), and four of Caecilia (nigricans, volcani, isthmica, and leucocephala) occur in Central America. New information about the geology of the region permits reevaluation of the biogeographic history of the group. Data for specimens, distribution maps, and a key are provided.

Twenty-nine populations of Xiphophorus fishes representing nine species of northern swordtails, one southern swordtail and a platyfish were assayed electrophoretically for allozyme variation. Phylogenetic relationships were inferred using parsimony and likelihood analysis of gene frequency characters, as well as Fitch-Margoliash, minimum evolution and neighbor-joining analyses of genetic distances. The phylogenetic relationships among species that were well supported in all analyses included (1) monophyly of the northern swordtails, (2) the pygmaeus clade of Xiphophorus nigrensis, X. multilineatus, and X. pygmaeus, and (3) the clade of X. nigrensis and X. multilineatus. Of those species represented by more than one population, all analyses supported monophyly of X. montezumae and weakly supported monophyly of X. nezahualcoyotl and X. birchmanni. Only the distance analyses supported monophyly of X. cortezi, and the support was weak. Finally, all analyses supported a clade including X. nezahualcoyotl from the Río Tamesí drainage and some populations from the Río Pánuco drainage, that is, nonmonophyly of the set of populations from the Río Pánuco drainage. Previously published trees based on morphology, behavior and randomly amplified DNAs were generally congruent with the optimal trees for the allozyme data and were not rejected by those data; in contrast, trees based on DNA sequences were more incongruent with the optimal trees for the allozyme data and were rejected by those data.

We studied the spring emergence of red-sided gartersnakes (Thamnophis sirtalis parietalis) from a large communal den in Manitoba to clarify the context in which courtship and mating occur. In particular, is the mating system in such a massive aggregation (> 20,000 snakes) substantially different from that at smaller dens? Radio-tracked female snakes stayed near the den for a few days postemergence, apparently waiting until they recovered locomotor ability after the long hibernation period, before setting out for their summer ranges. Females dispersed from the den in all directions, rather than following distinct migration corridors. Male snakes moved frequently and spent much of their time far from the den in surrounding woodland. Most males remained near the den for only a small proportion of the entire mating season, apparently because of high rates of energy expenditure during mate-searching and courtship. Courting groups contained from 1–62 males and were largest close to the den. Most courting and mating occurred in groups of less than five males, often more than 20 m from the den. These small group sizes resulted from the females' dispersal prior to mating. Larger groups did not induce female cooperation (mating) more quickly than small groups. Despite the spectacular aggregations of courting snakes within the den, most reproductive activity in this population (as in other gartersnake populations) occurs in small groups, widely dispersed over a broad area.

The following four pomacentrid fishes are described, all endemic to the Marquesas Islands: Chromis abrupta, distinct in having XII,11–13 dorsal rays; II,11–12 anal rays; two spiniform procurrent caudal rays; 16–18 pectoral rays; 16–18 tubed lateral line scales; and dark brown color with an abruptly white caudal fin. Chromis fatuhivae, with XII,12–13 dorsal rays; II,12–13 anal rays; two spiniform procurrent caudal rays; 17 pectoral rays; 15 tubed lateral line scales; and dark brown color to a vertical below sixth dorsal soft ray, then white. Chromis flavapicis, with XIII,12–13 dorsal rays; II,11 anal rays; three spiniform procurrent caudal rays; 18–20 pectoral rays; 16–18 tubed lateral line scales; and dark gray-brown color with yellow-tipped dorsal spines, the young entirely yellow. Stegastes robertsoni, with XII,15 dorsal rays; II,12–14 anal rays; 19–20 (usually 20) pectoral rays; 19–20 (usually 20) tubed lateral line scales and dark gray-brown color, the axil and upper base of pectoral fins with a black spot. Chromis abrupta seems closest to the wide-ranging Indo-Pacific C. margaritifer. No similar species was noted for C. fatuhivae, known only from the island of Fatu Hiva. Chromis flavapicis is most similar to C. analis that ranges from the western Pacific east to Samoa and C. pembae from the western Indian Ocean and Red Sea. Stegastes robertsoni was formerly misidentified as S. nigricans.

Based on mark-recapture data collected over seven years on the salamander Plethodon kentucki, I examined (1) longevity and long-term site fidelity, (2) growth curves for each sex derived from both cross-sectional and longitudinal data on body size, (3) whether growth curves generated from the two kinds of data were comparable, and (4) how the relationship between adult body size and age in this species compares to that in other plethodontid salamanders. Recapture rates indicate that about 86% of males and 82% of females survived and remained in the study area from one year to the next. Most individuals recaptured at the end of the study period were within, or less than 2 m from, the home range they occupied at the beginning. Maximum age estimates were 13 yr for males and 16 yr for females. Growth curves derived from cross-sectional and longitudinal data were very similar. For both sexes, there is rapid growth up to the time of first reproduction (about 4 and 5 yr for males and females, respectively) and continued growth for 2 to 4 yr afterward but relatively little growth after 9 yr of age. Males may have a greater rate of growth prior to sexual maturity, but females grow for a longer period and attain a greater body size. There is much variance in adult body size within a given age class for both sexes. The correlation between body size and age was slightly greater in males than in females, and the correlation was significant for the combined data. Similarly, the size-age correlation in other plethodontid species is stronger for males than for females, which may be because of a greater variability in growth after sexual maturity in females than in males.

Phoxinus saylori is a new cyprinid described from the Tennessee River drainage. This distinctive minnow is one of seven described North American Phoxinus species and one of four that occurs in Tennessee. It differs from all congeners by the combination of two uninterrupted black lateral stripes and development of black pigment on the underside of the head of nuptial males. Based on coloration and tuberculation patterns, P. saylori is hypothesized to be part of a monophyletic group comprised of P. oreas, P. tennesseensis, and P. cumberlandensis. Phoxinus saylori appears to be very rare; it is currently known from only six localities on the Walden Ridge portion of the Cumberland Plateau. Human activities such as agriculture and timbering threaten its future existence.

Offspring phenotype can be affected by maternal effects, developmental conditions, and clutch identity. We examined the contribution of maternal effects, egg incubation temperature, and clutch identity to variation in hatching success and hatchling body size of the snapping turtle, Chelydra serpentina. We collected 726 eggs representing 24 clutches from the John Heinz National Wildlife Refuge in 1997. We examined a subset of eggs (78) for water and solid content and incubated the remaining eggs. Wet shell and wet nonshell made up 10.96% and 88.05% of the total egg mass, respectively, and dry solids, dry shell, and total water accounted for 22.78%, 7.14%, and 70.07% of total egg mass. Both mass of total water and solids in the nonshell fraction increased with egg size, although solids accounted for slightly less proportional mass in large eggs than in small eggs. Egg mass was correlated with mass at hatching, but explained only 47% of the variation in mass at hatching. Both clutch identity and egg incubation temperature affected hatching success and hatchling size. Although maternal effects no doubt play an important role in determining hatchling size, other factors, independent of maternal effects, influenced hatchling size.

A new species of the mailed catfish genus Harttia is described from the São Francisco River drainage, States of Minas Gerais and Bahia, Brazil. The new species is distinguished from congeners by the combination of an abdominal region covered by small bony plates, plates 3–4 times in eye diameter; interorbital width 3.1–4.0 in head length and greater than eye diameter; body width at anal fin origin 6.3–8.3 in standard length; margins of the head and pectoral fin spine of mature males with elongate and conspicuous odontodes; anal fin of males longer than of females. A key to Harttia species and a comparison with other species are provided.

Uma nova espécie de cascudos do gênero Harttia é descrita da drenagem do rio São Francisco, nos estados de Minas Gerais e Bahia, Brasil. A nova espécie é prontamente diferenciada das demais espécies por possuir a seguinte combinação de caracteres: região abdominal revestida por placas ósseas pequenas (3–4 vezes o diâmetro do olho), desde a cintura escapular até as placas pré-anais; largura interorbital maior que o diâmetro do olho, 3,1–4.0 vezes no comprimento da cabeça; corpo delgado, sua largura na altura da origem da nadadeira anal 6,3–8,3 vezes no comprimento padrão; margens do focinho e acúleo da nadadeira peitoral dos machos maduros com odontodes longos e conspícuos e nadadeira anal dos machos muito mais longa do que nas fêmeas. Apresenta-se uma chave de identificação e uma comparação entre o novo táxon e as demais espécies.

A recent evolutionary ecological model of facultative paedomorphosis predicts that body size of mature individuals should be larger than immatures of the same cohort. We investigated sex-specific differences in body size and maturation within a single cohort of branchiate (= larval and paedomorphic) mole salamanders, Ambystoma talpoideum. In addition, we also sampled the population after the breeding season, as some individuals began to undergo metamorphosis and leave the pond. The branchiate population was female-biased (62.7%), and mature (paedomorphic) females were significantly smaller than paedomorphic males or immature (larval) females. The majority of male branchiates were mature (86.6%), whereas significantly fewer females were mature (64.4%). After the reproductive season, males and females underwent metamorphosis in the same proportion in which they occurred in the branchiate population, although a significantly greater proportion of immature females metamorphosed (64.6%) compared to their frequency in the branchiate population (35.6%). There were no significant differences in body size with regard to sex or maturation among metamorphosing individuals. Our data demonstrate that maturation in branchiates is independent of body size in males and that it may negatively affect body size in females. Our findings underscore sex as a potentially important factor, and question the role of body size, in regulating this life cycle polymorphism in A. talpoideum.

A new species of killifish, Lebias stiassnyae, is described from Lake Afdera, Ethiopia. It is readily distinguished from all congeners by the unique combination of a sharply upturned lower jaw oriented nearly perpendicular to the body axis, an open cephalic neuromast system, the lack of an interarcual cartilage, an obliquely positioned pectoral fin base, and a large body size.

In recent years, the pattern of maximal caudal autotomy in lizards has come under consideration, with attention being focused on how nonsegmental muscles in the tail base, specifically the m. caudofemoralis longus and the m. retractor penis magnus, may limit autotomy where they cross autotomy planes or, alternatively, how they may be ruptured if maximal autotomy is practiced. In this paper, we demonstrate that in the lacertid lizard Podarcis hispanica a number of autotomic vertebrae are spanned by the m. caudofemoralis longus, that maximal caudal autotomy does occur, and that the caudofemoralis muscle dissociates from its vertebral attachments but is not torn in the process. Anatomical and histological data reveal that this muscle has a specialized structure and relationship with surrounding muscles, skeletal elements, and connective tissues that result in minimal damage upon maximal autotomy. Furthermore, upon caudal regeneration, the m. caudofemoralis longus reestablishes contact with the newly formed cartilaginous axial skeleton of the tail.

Gerres silaceus n. sp. is described from the holotype and two paratypes from the southern Malay Peninsula. The species is included as the fourth species in the “G. setifer complex” [G. chrysops Iwatsuki, Kimura and Yoshino, G. decacanthus (Bleeker), G. setifer (Hamilton), G. silaceus n. sp.], differing from all other congeners from the Indo-Pacific in having two supraneural bones and small size (less than 100 mm in standard length vs three supraneural bones and adults > 100 mm SL). The new species is further characterized by presence of IX, 10 dorsal fin rays, 34 or 35 lateral line scales, 3.5 scales between the 5th dorsal fin spine base and lateral line, caudal fin short (mean 29% of SL), slender second anal fin spine, pelvic fin ray with a wide white margin posteriorly, and a uniformly silvery ocher body. Gerres silaceus differs from G. setifer and G. decacanthus in body color, the last dorsal fin spine slightly shorter or similar length to the penultimate spine, higher gillraker counts and broadly rounded caudal fin lobes; it differs from G. chrysops in higher gillraker counts, rounded caudal fin lobe posterior margin and body color. The four species are generally distributed allopatically in the Indo-western Pacific.

Male midwife toads emit a short, tonal advertisement call. Previous studies have shown that two nearby males engaged in acoustical competition (duet) increase their calling rate. We address the question of whether acoustical competition is expressed in the temporal adjustment of the calls of nearby calling males. One male emits its calls typically immediately after the emission of a nearby male with an approximate phase angle of 80°. Variation in timing of calls is correlated with the size of the calling male (as inferred by call frequency). Playback experiments with females show that the timing of calls between interacting males can influence the choice of a mate. Females prefer duets of males calling with a phase angle of 180° rather than 90° and prefer males responding to calls over males initiating the duets.

We studied the impact of restrictions by the thermal environments on body temperatures (T_bs) and microhabitat use of the lacertid lizards Podarcis melisellensis and Podarcis muralis in a Mediterranean area (Croatia) during autumn. The thermal conditions at available microhabitats were assessed with copper models that measured the operative temperatures (T_e) at different sites. We estimated the thermal suitability of microhabitats by quantifying the extent of similarity between the T_es and the range of selected temperatures (i.e., the T_bs that lizards maintain in zero-cost conditions in a laboratory thermogradient; T_sel). Both species maintained, throughout most of day, T_bs that were on average 2–4 C below both T_sel and the T_bs recorded in the field during summer. Nevertheless, the T_bs measured during autumn were in the upper range of available T_es and were much closer to the T_sel than were the T_es. In addition, lizards were most often observed in the warmest microhabitats and were often seen basking. These results indicate that lizards were actively thermoregulating. The T_e measurements show that lizards encounter suitable thermal conditions (i.e., where T_es is within T_sel) in only a restricted subset of the available microhabitats and during only a relatively short period of the day. Thus, lizards are constrained to maintain relatively low T_bs during autumn by the generally low available T_es. Although lizards were clearly thermoregulating, they appeared to accept lower T_bs during activity in autumn than in summer. A possible reason for this seasonal shift in activity T_bs is that achievement of higher T_bs during autumn is only feasible by confining activities to some specific microhabitats, which may severely constrain other behaviors, such as foraging.

We studied perch height in a population of the arboreal lizard Anolis nebulosus from Chamela, Jalisco, México. A total of 1697 lizards were captured during 1988 (June through December), 1989, 1990, and 1991 (June through July). Males used higher perches than females, particularly during the reproductive season. At the beginning of the reproductive season (March) males started to use higher perches, which were highest during the peak of reproductive activity. However, perch height use by females did not follow the same pattern. Females used high perches in March before beginning reproduction, lower perches during the reproductive season from June to August and higher perches again in October at the end of reproductive activity. These patterns suggest that reproductive activity is an important factor determining differential perch height use between sexes, with the priority for males being courtship displays and defense of their territory, whereas protection from predators is more important for females. Adults used significantly higher perches than juveniles and hatchlings, and overall perches were significantly higher during the wet than during the dry season. Perch height of females and males increased with body, environmental, and microenvironmental temperatures, suggesting that perch height might play an important role in thermoregulation.

We describe a new species of Platymantis from the Weitin River Valley on the southern tip of New Ireland in the southwest Pacific, bringing to seven the number of native frogs known from that island. We also briefly report on the ecology of the four species of Platymantis occurring on New Ireland and comment on the biogeography of the frog fauna.

The Proceratophrys bigibbosa species group is characterized by the presence of postocular swellings and absence of hornlike palpebral appendages. A new member of this group is described from Rio Grande do Sul, southern Brazil. Proceratophrys brauni sp. nov. is known from the southern regions of the Serra Geral, where it inhabits small streams in subtropical rain forests. It is characterized by the pointed snout, development of palpebral tubercles, and black ventral surface spotted with red. Its body size is intermediate between the smaller Proceratophrys avelinoi and the larger P. bigibbosa, both being redescribed here. Life histories of these three species and advertisement calls of P. bigibbosa and P. brauni are briefly described. An identification key to the members of the bigibbosa group is provided, and new distributional data are given. The type locality of P. avelinoi is specified, and Proceratophrys cristinae is considered a junior synonym of P. bigibbosa.

A new species of toad, Bufo chavin, is described from two localities (3010 and 3070 m) from the eastern Andean slopes of central Peru (Departamento de Huánuco, Provincia de Pachitéa, Distrito de Chaglla) where it occurs sympatrically with Bufo spinulosus. Bufo chavin is referred to the Bufo veraguensis group. The new species differs from all members of this group by having large, elevated, elongate glands on each forearm and tibia, two large, elevated, elongate glands on the outer dorsal margin of each foot and one small, elevated gland on the outer dorsal margin of each hand. Eggs are relatively large, yolky and unpigmented in the new species.

Se describe una nueva especie de sapo, Bufo chavin, procedente de dos localidades (3010 y 3070 m) en la vertiente oriental de los Andes del Perú central (Departamento de Huánuco, Provincia de Pachitéa, Distrito de Chaglla) donde se presenta simpátricamente con Bufo spinulosus. Bufo chavin es incluido al grupo Bufo veraguensis. La especie nueva difiere de todos los miembros de este grupo por tener una glándula larga, elevada y elongada en cada antebrazo y tibia; dos glándulas grandes, elevadas y elongadas en el margen dorsal externo de cada pie; y una glándula pequeña elevada en el margen dorsal externo de cada mano. En la especie nueva, los huevos son relativamente grandes, presentan abundante yema y no están pigmentados.

Population estimates of the Devils Hole pupfish (Cyprinodon diabolis) extending over a 25-year period reveal an annual population cycle that reaches a low during spring and a high during fall. The four earliest years (1972–1976) preceded a U.S. Supreme Court water rights decision intended to protect pupfish habitat. Mean and maximum population sizes during those four years were significantly lower than during subsequent periods examined through 1997, and annual minimum population size was significantly lower during 1972–1976 than during 1991–1997. Annual maximum population size is positively correlated with water level for the month in which it occurred as well as for the month one year prior to the time of the estimate. The lowest historic water levels occurred during the period 1972–1976, and over the past 60,000 years comparable or lower water levels may have occurred only during the altithermal, about 6000 years before the present. During these two periods the Devils Hole pupfish population has probably experienced its most severe bottlenecks.

We studied three populations of the midget faded rattlesnake (Crotalus viridis concolor) in Wyoming to obtain data on reproduction and movements of pregnant females. Pregnant females emerged from hibernation, moved a short distance to a rookery, then moved very little for the remainder of gestation. During this time, females were not observed to forage or mate. Offspring were born between 20 August and 18 September. Mean litter size was 4.7 and was significantly related to female snout–vent length (SVL). Mean offspring SVL = 193 mm, mean offspring mass = 8.0 g; neither was related to female SVL. Litter mass was significantly related to female SVL, suggesting females invest energy into more offspring as opposed to larger offspring. Females appear to reproduce every two to three years. Sex ratio was 1:1 for data collected in 1997 but was significantly female biased for data collected before 1995. These data are compared to those reported for other populations of this species.

Recently, populations of Etheostoma tippecanoe from the Tennessee River drainage were described as a new species, Etheostoma denoncourti. Although populations of E. tippecanoe from the lower Tennessee River (Duck and Buffalo Rivers) were assigned to the new taxon, the species description did not contain an analysis of specimens from these rivers. To evaluate the phylogenetic placement of these unanalyzed populations with respect to all other populations of E. tippecanoe and E. denoncourti, we assembled a dataset composed of DNA sequences (complete cytochrome b) from 32 individuals representing all known populations of these species. Parsimony analysis of these populations, 11 other darter taxa, and five outgroup taxa resulted in 3868 equally most-parsimonous trees at 1687 steps. Populations from the Duck and Buffalo Rivers were always resolved as members of the newly described taxon, E. denoncourti, consistent with the original description. Further, E. tippecanoe and E. denoncourti were resolved as monophyletic sister taxa in all most-parsimonious trees. The amount of cytochrome b sequence divergence separating these two taxa (5.63%) is within the range observed for cytochrome b variation between other species of darters.

Skeletochronology of sea turtle humeral bones has been validated only for juvenile Caretta caretta. Our recovery of a sea turtle marked with oxytetracycline (OTC) and at large for eight years shows that annual growth marks continue to be deposited in adult C. caretta. In addition, the presence of a fluorescent mark eight years after injection shows that OTC can be used in long-term growth studies. Growth and OTC marks are not equally distinguishable around the entire edge of the humerus making the location of bone biopsies critical for determining growth and OTC marks. Although bone biopsy sections may be used with OTC to count growth marks, they cannot be used to measure radial growth or to make back calculations of age. Instead, whole humeral sections must be used.

Pigmentation in fishes is known to be variable both among individuals of a species and within individuals over time. Use of pigment characters for taxonomic diagnoses must, therefore, be carefully considered. I present experimental evidence showing that pigment characters previously considered diagnostic for three small African ‘Barbus’ species may differ between living and preserved specimens and that lasting changes in these characters can be induced experimentally by placing fishes in a different, less turbid environment. Lateral line pigmentation and presence of a spot on the caudal peduncle showed significant changes that resulted in different species identifications before and after the experiment. These pigment patterns are thereby shown to be labile, nontrenchant characters having little or no diagnostic utility. ‘Barbus’ amphigramma Boulenger, 1903, and ‘Barbus’ taitensis Günther, 1894, are thus shown to be junior synonyms of ‘Barbus’ paludinosus Peters, 1852.

A full advertisement call in the tokay gecko (Gekko gecko) is made up of two phases. The first phase consists of 2–3 successive rattles of increasing intensity. The second phase contains a series of 4–11 binotes (mean 6.5), each of which sounds like “gerjai”. All rattles and binotes have the same fundamental frequency of about 100 Hz (90–115Hz). A rattle has a dominant frequency of 835 Hz with almost all energy density below 4 kHz. The first note of each binote contains 11 distinct harmonics with varying dominant frequency. The dominant frequency and harmonics in the second note of the binote gradually vary from the first binote to the last one. Advertisement calls of tokay geckos show diel cycles and seasonal variations. Light and ambient temperature strongly affect the vocal activity in both field and laboratory. The frequency of advertisement vocalization increases in late spring in parallel with the rise of androgen levels and gonadal masses.

Etheostoma zonale, the banded darter, was introduced to the Susquehanna River basin, Pennsylvania, through an interbasin transfer. We examined the effects of darter density and the presence of E. zonale on the substrate choice of two native darter species (Etheostoma olmstedi, the tessellated darter, and Percina peltata, the shield darter) in an artificial stream. In single species trials, E. olmstedi, E. zonale, and P. peltata exhibited nonrandom substrate selection and occupied patches of large substrate significantly (P < 0.05) more often than expected. No intraspecific density effects were observed. The presence of E. zonale did not affect the substrate choice of P. peltata but did induce a shift of E. olmstedi from large to small substrate in high-density trials (P < 0.05). Etheostoma zonale was most frequently the aggressor in behavioral interactions. Neither E. olmstedi nor P. peltata directed any agonistic behavior toward E. zonale; however 40% of aggressive acts initiated by E. zonale were directed toward E. olmstedi and P. peltata. Displacement of E. olmstedi by the aggressor E. zonale suggests potential deleterious effects on the native species.

The Cnemidophorus laredoensis subgroup of parthenogenetic whiptail lizards comprises clonal complexes A and B, with each form having a mostly allopatric distribution area that includes only a few sites of syntopy with the other form and a distinctive ensemble of morphological characters. The evolution of these clonal complexes is most readily explained by the hypothesis of a hybrid C. gularis × C. sexlineatus derivation for form A, originally described from Laredo, Webb County, Texas, and a second hybridization involving these species to account for form B. Reciprocal skin-grafting, previously used in studies of genetic structure in the parthenogenetic species C. tesselatus, C. neomexicanus, C. uniparens, and C. velox, provides a methodology for differentiating between the descendants of different parthenogenetically capable interspecific hybrids. We used individuals of C. laredoensis A from six sites in Texas and individuals of form B from three of these sites in reciprocal skin-grafting experiments in which each lizard of clonal complex A rejected all grafts from B lizards and each lizard of clonal complex B rejected all grafts from A lizards. We accept these data as verification of separate hybrid origins for C. laredoensis A and B.

Curimata vari Gaye-Siessegger and Fricker, 1998, described from the rio Cubatão drainage, southeastern Brazil, is compared to other curimatid species. It lacks the synapomorphies that diagnose Curimata Bosc and must be considered a Cyphocharax species, according to the current definition of the genus. A comparative analysis of the morphometric data for C. vari, Cyphocharax santacatarinae, and C. voga indicates that C. vari Gaye-Siessegger and Fricker is a subjective junior synonym of C. santacatarinae Fernández-Yépez.

Videoradiographic analyses were made of hissing in puff adders (Bitis arietans). During the hiss the larynx remains relatively stationary immediately adjacent to the internal nares. The exhalatory portion of the hiss is characterized by a distinct expansion of the caudal buccal cavity, including a depression of the hyoid and divergence of the cornua. This buccal expansion is hypothesized to be an epiphenomenon of intraoral pressure generated by the exhalatory airstream of the hiss.

Examination of the type material of Anolis bourgeaei Bocourt revealed that the lectotype is referable to Norops laeviventris (Wiegmann), and the paralectotype is a Norops sericeus (Hallowell). I conclude that the nominal taxon A. bourgeaei Bocourt is a junior synonym of N. laeviventris (Wiegmann).

The tadpole of Atelopus mindoensis is described. In general morphology, it is similar to the other larvae known for the genus. Based on its color pattern, it is placed in the group of tadpoles with multiple symmetrical or asymmetrical light marks in life.

Se describe el renacuajo de Atelopus mindoensis. En su morfología general es similar a las otras larvas del género conocidas. Basada en su patron de coloración, se pone en el grupo de los renacuajos con múltiples manchas corporales con una organización simétrica o asimétrica.