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We augmented existing genetic datasets with nucleotide sequences from Recombination Activase Gene 1 (RAG-1) and an intron in the RNA fingerprint protein 35 (R35) for Macrochelys temminckii (Chelydridae), and from the nuclear gene Glyceraldehyde-3-phosphate Dehydrogenase (GAPDH) for Macrochelys temminckii, Apalone spinifera (Trionychidae), Trachemys scripta (Emydidae), Sternotherus odoratus (Kinosternidae), Staurotypus triporcatus (Kinosternidae), Chelydra serpentina (Chelydridae), Dermochelys coriacea (Dermochelyidae), Platysternon megacephalum (Platysternidae), and Chelonia mydas (Cheloniidae) to address the phylogenetic relationships of the Chelydridae. Our study finds support for a sister group relationship between Chelydridae and either the clades Kinosternoidea (Kinosternidae Dermatemydidae) or Chelonioidea (Cheloniidae Dermochelyidae). Further analysis also suggests that the speciation events leading to these clades occurred in rapid succession, within approximately one million years of each other.
We redescribe Catostomus utawana using specimens from an extant population and museum collections from the Adirondack region of New York and compare it to the widely distributed Catostomus commersonii. These species differ from each other in body depth, relative lengths of pectoral, anal, and pelvic fins, in the lengths of the dorsal-fin and anal-fin bases, and in several characteristics related to head shape and body depth. Catostomus utawana females in breeding condition have well-developed pearl organs on the anal fin, ventral lobe of the caudal fin, and on most of the scales found on the ventral half of the body posterior to the dorsal fin. Catostomus commersonii females in breeding condition usually lack pearl organs. Catostomus utawana males in breeding condition are extensively covered in pearl organs, whereas the pearl organs on C. commersonii males are typically limited to the anal and caudal fins, scales posterior to the dorsal fin, and on the head. Catostomus utawana males in breeding condition have a gold mid-lateral stripe and a gold patch above each eye; breeding females lack gold coloration. Catostomus utawana males and females lack red coloration throughout their spawning season. We propose using the common name of Summer Sucker for C. utawana.
Anurans have long been a model system for studies of animal communication, but little is known about how individuals acquire acoustically linked mating behaviors. The manner in which behaviors are acquired may be a source of variation in these behaviors. In this study, we reared Physalaemus pustulosus in four acoustic treatment groups: hearing a conspecific chorus of P. pustulosus frogs, acoustically isolated from all frog calls, hearing a chorus of the congener P. enesefae, and hearing noise. We then measured the spectral and temporal characteristics of the calls produced by males and tested them for differences between treatment groups. Males reared in isolation produced calls that were shorter in duration. Females showed discrimination against these shorter calls. Early experience can alter the advertisement call of male P. pustulosus, and acoustic isolation leads to the acquisition of calls that are less attractive to females. Males reared in other groups produced species-typical calls. The calls of male P. pustulosus may be the product of a gene by environment interaction.
Previous studies revealed sexual dimorphism in terrestrial plethodontid salamanders of the genus Plethodon for greater snout–vent length (SVL) at first reproduction and maximum SVL in females, presence of a mental gland in males, larger vomeronasal organ (VNO) in males, and greater internarial width in males. Here I describe additional sexual dimorphism as well as seasonal (i.e., breeding versus non-breeding) dimorphism in Plethodon kentucki. I measured morphological variables on preserved specimens of adult individuals that were collected from Wise Co., Virginia during the breeding season (n = 26 females and 30 males) and non-breeding season (n = 29 females and 30 males). Residuals from regressions of morphological variables on SVL (all log10-transformed) and a principal component analysis on the residuals demonstrate that body mass, trunk length, and tail width are greater in females. These female features may be associated with selection for greater fecundity and increased fat storage to enhance reproductive success. The head is relatively larger in males and has a longer snout with a broader tip (i.e., greater orbitonarial distance and internarial width). Such dimorphism for the snout increases during the breeding season. Sexually dimorphic features in males may be associated with selection for increased mating success in terms of finding reproductive females (i.e., the enlarged snout may be related to a larger VNO and enhanced chemosensory function) and increased competitive ability during competition for mating opportunities (i.e., the larger head may result from selection for better fighting ability). An increase in vent length for both sexes may facilitate the indirect transfer of sperm during the breeding season.
The electric fish genus Platyurosternarchus, family Apteronotidae, is reviewed based on both external morphology and osteology. Synapomorphies for Platyurosternarchus are identified, the genus is diagnosed, and a key to the species is provided. Platyurosternarchus crypticus, a new species, is described from the upper reaches of the Rio Branco in the northern portions of the Amazon basin. Platyurosternarchus macrostoma from the Amazonas, Orinoco, and Essequibo River basins is redescribed. The species differ in the form of the laterosensory canal segment in the soft tissues of the ventral portion of the head and within the preopercle, the posterior extent of the mid-dorsal electroreceptive filament, and the morphology of the first and fourth branchiostegal rays.
Mystus cineraceus, new species, is described from the Irrawaddy River drainage in northern Myanmar. It is distinguished from congeners in having a unique combination of a long-based adipose fin (40.9–45.9% SL) that contacts the base of the last dorsal-fin ray anteriorly, a color pattern consisting of a uniform brownish-gray body with a diffuse dark midlateral line and a diffusely dark tympanic region (very indistinct in some individuals), 13–15 rakers on the first gill arch, dorsal-fin spine length 10.9–13.4% SL, body depth at anus 20.7–23.4% SL, head length 24.1–27.2% SL, maxillary barbel reaching to middle of anal-fin base (247.4–345.0% HL), absence of a black spot at the base of the dorsal-fin spine and at the base of the caudal fin, and cranial fontanel reaching the base of the supraoccipital spine. The issues surrounding the identification of M. bleekeri, a species from India similar to M. cineraceus, are also discussed.
Many important questions in ecology and conservation biology require assessment of the body condition of animals, which is often achieved using mass and length data. However, fully quantitative condition indices can be difficult to obtain in the field for large taxa like marine turtles. Therefore, rapid visual-assessment techniques for categorizing condition can be useful for field studies. Here, we test whether a visual method of categorizing body condition in the Green Turtle (Chelonia mydas) based on the shape of a turtle's plastron is comparable to two commonly used body condition indices derived from mass and length measurements. Condition scores for both mass–length indices varied in the expected manner with our visual condition categories, verifying that the rapid visual assessment technique accurately reflects differences in body condition. This technique should aid many field studies of turtles where body condition data are required but mass data cannot easily be obtained.
We report the oldest reliably identified and dated specimen of Gasterosteus aculeatus. The specimen was found after several decades in storage, and we used siliceous microfossils to infer its depositional environment, provenance, and age. The specimen came from a 13.0 to 13.3 Ma deposit in the Monterey Formation of California, probably from the Alta Mira Shale of Palos Verdes. Gasterosteus aculeatus is a highly polytypic and polymorphic species complex. Although this specimen exhibits extreme morphology for this complex, it is not distinctly different from modern Threespine Stickleback for measurable traits, and we consider it to be within the G. aculeatus species complex. Its morphology resembles that of modern marine or anadromous stickleback, which is consistent with the paleoecology of the Alta Mira Shale. Its presence in this deposit, however, is more consistent with a cooler ocean temperature inferred from planktonic diatoms than with the warmer temperature inferred from near-shore, benthic mollusk and epipelagic fish assemblages.
We studied the population dynamics of Bufo schneideri and B. rubescens during three years in the Cerrado biome of central Brazil. Using mark–recapture models, we estimated demographic parameters and evaluated the effects of sex and climate upon them. We used model selection, based on the Akaike's information criterion (AICc), to test hypotheses of variation in demographic parameters. The adult sex ratio was male-biased for both species, and breeding took place in the dry season for B. rubescens and in the transition from dry to wet season for B. schneideri. There was no difference in recapture probability between sexes, but there was significant variation among months. Recapture probability was associated with rainfall and temperature of the previous month in B. rubescens, but had constant values for the same months in different years in B. schneideri, showing a cyclic seasonal pattern. Survival estimates were constant in time and no significant difference was found between sexes in both species. Annual survival was 0.35 for females and 0.37 for males of B. schneideri, and 0.34 for males and 0.38 for females of B. rubescens. We found no evidence for temporary emigration in both populations, but the presence of transients was significant. For both species, adult population size was moderate, with larger values during the breeding season. The similar demography of B. rubescens and B. schneideri illustrates the high ecological and morphological conservatism reported in the genus Bufo.
Population structure of Gray Snapper (Lutjanus griseus) in U.S. waters was assessed via analysis of allele and genotype distributions at 13 nuclear-encoded microsatellites and mitochondrial (mt)DNA haplotype distribution among samples from five localities in the northern Gulf of Mexico (Gulf) and one locality on the Atlantic coast of Florida. Exact tests of homogeneity over all microsatellites were significant for both allele (P = 0.004) and genotype (P = 0.020) distributions; homogeneity tests for mtDNA haplotype distributions were not significant (P = 0.940). Weak but significant divergence (ΦCT = 0.007, P = 0.020) among localities (microsatellites) was indicated by spatial analysis of molecular variance (SAMOVA), where three distinct groups (one from the northwestern Gulf, one from the northcentral/northeastern Gulf, and one from the east coast of Florida) were inferred. Spatial autocorrelation analysis (microsatellites) revealed an isolation-by-distance effect among samples from the northern Gulf. Levels of genetic variation in both microsatellites and mtDNA were low as compared to other lutjanids in U.S. waters, and Bayesian analysis of genetic demography revealed a two to three order-of-magnitude decrease in effective population size of Gray Snapper over the past 5,300 or so years (0.05 quartile of 81 years). The evidence of genetically distinct stocks and the decline in effective population size have implications for management of Gray Snapper resources in U.S. waters.
A new species of treefrog is described from the central region of the Western Sierra Madre del Sur of Guerrero, Mexico. This frog is a member of the genus Charadrahyla, which contains five other species that are restricted to mesic highlands in Mexico. It possesses extensive webbing and in particular a hypertrophied membrane between toes I and II. This characteristic distinguishes the species from all other Middle American hylid frogs, except C. trux that also occurs in Sierra Madre del Sur of Guerrero. From C. trux the new form differs in being smaller, having relatively longer legs, aspects of coloration, and in having more prominent cloacal ornamentation.
The small, introduced poeciliid Gambusia holbrooki is widely distributed in Australia, and is widespread and generally abundant in lacustrine environments near Perth, Western Australia. Laboratory feeding trials and field investigations were conducted to evaluate the impact of this species on native frogs in southwestern Australia. The eggs of Crinia georgiana, C. insignifera, Litoria adelaidensis, and L. moorei were not consumed by G. holbrooki. In contrast, Crinia georgiana, C. insignifera, C. glauerti, and Litoria moorei hatchlings (Gosner stage 20–23) were consumed by G. holbrooki. Alternative aquatic invertebrate prey (mosquito larvae and Daphnia) were preferred over hatchlings. Gambusia holbrooki were recorded at 20 of 25 wetlands surveyed, and frogs occurred at all 25 sites. From one to six frog species occurred at wetland sites where fish were present. Frog species richness, and the presence of individual species, did not differ between sites with and without G. holbrooki. However, frog species richness was positively correlated with wetland condition (highly ranked sites were relatively undisturbed). In contrast to the situation in eastern Australia, populations of anuran species in southwestern Australia do not appear to be strongly affected by this small invasive fish. This difference is likely related to climatic dissimilarities that affect the population biology of fish and frogs in these regions. Additional factors that may influence the level of impact of G. holbrooki include egg deposition site, timing of anuran breeding, availability of alternative prey, wetland condition, and seasonal variation in fish size and abundance.
We examined patterns of community structure and microhabitat requirements of Pristimantis frogs at sites of high geographic proximity in the Tambopata region of southeastern Peru. Herpetofaunal surveys were conducted at five sites encompassing approximately 131 square km of Tambopata Province, including EcoAmazonía (EA), Reserva Amazónica (RA), Explorer's Inn (EI), Sachavacayoc Centre (SC), and Tambopata Research Center (TRC). In addition to sampling and identifying all species of Pristimantis captured, environmental variables, including substrate, perch height, leaf litter depth, tree cover, and time of day, were collected and analyzed. Total frog encounters, species richness, diversity, and community similarity differed significantly among sites. Generally, similarity, richness, and diversity were not closely related to geographic proximity, but total abundance was. More individuals were captured at SC and TRC, whereas more total species were captured at TRC and EI. Diversity was the highest at TRC, followed by RA, EI, EA, and SC. Encounters of P. toftae and P. peruvianus also differed significantly among sites, with one species rarely encountered where the other was prevalent. Generally, more individuals of Pristimantis were captured during the wet season at all five sites. Significantly more individuals were captured during the night than the day. Significantly more individuals as well as species were captured on leaves and the ground versus all other substrate types, with more on leaves at night and on the ground during the day. Significantly more adults were captured higher off the ground than juveniles, with males found higher than females. There was no significant relationship between frog encounters and leaf litter or tree cover. Pristimantis peruvianus was shown to exhibit differences in microhabitat usage from P. toftae. We conclude that many factors contribute to the observed differences in diversity among the sites, requiring future studies that will also examine other environmental variables such as forest type, soil characteristics, and prey availability.
A new species of lungless salamander (Plethodontidae) is described from the mountains of eastern Guatemala. The new species is distinguished from all other members of its genus by its yellow ventral coloration. It is geographically closest to its sister taxon, Cryptotriton veraepacis, from which it differs in several osteological features as well as nostril size and shape. Molecular analyses with allozyme loci and mitochondrial DNA also support its distinctiveness from C. veraepacis. This miniaturized species inhabits cloud forest habitats and has been found most commonly in bromeliads.
Trematomus nicolai is a near shore benthic notothenioid fish most abundant in the subzero shelf waters of East Antarctica. During recent collecting we obtained the first specimens of this species from West Antarctica (the Bransfield Strait), and we compare these with specimens from the Ross Sea (McMurdo Sound) in East Antarctica. Because T. nicolai has been frequently misidentified as T. tokarevi, we provide several non-meristic characters that separate these species. We employ a radiographic technique for rapid visualization of the cephalic lateral-line canals, an important diagnostic character in trematomids. Compared to those from McMurdo Sound, the Bransfield Strait specimens have lower ranges and mean counts for meristic characters, with significant differences for anal rays, pectoral rays, and vertebrae. Our data suggest a panmictic population, but the Bransfield Strait specimens live in water 3–4°C warmer than McMurdo Sound, and this may contribute to lower meristic counts. The mean buoyancy between the two samples is not significantly different. We examined sequence variation in the ND2 portion of the mitochondrial DNA (mtDNA) genome for evidence of population structure in samples from both areas. We identified 12 mtDNA haplotypes (haplotype diversity [h] = 0.978, nucleotide diversity [π] = 0.458%) and analysis of molecular variance (AMOVA) shows no significant global differentiation. A median-joining network that represents the genealogical relationships among the mitochondrial haplotypes also shows little separation between the samples from West and East Antarctica, and additional tests suggest the T. nicolai population is in equilibrium and of constant size. Trematomus nicolai exemplifies the potential of the Antarctic current regime for circum-Antarctic dispersal of a variety of organisms in the Southern Ocean.
Population regulation in pond-breeding amphibians has generally been assumed to occur through density dependence in the aquatic larval stage. However, studies examining terrestrial stage population dynamics are comparatively rare. As a consequence, the relative importance of density dependence in the terrestrial stage remains largely unknown. Here I determine the density dependence of terrestrial stage vital rates, including juvenile and adult survival, age and size at first reproduction, and reproductive traits, for a population of Wood Frogs, Rana sylvatica, in Michigan. I also examine the carry-over effects of density-dependent variation in metamorphic traits on adult demographic traits. During the 21 years of this study, the number of breeding adult males and females varied by an order of magnitude, whereas the number of metamorphic juveniles leaving the pond varied by two orders of magnitude. Adult male and female annual survival was negatively correlated with the number of males and females, respectively. Partial correlation coefficients (holding population size of the opposite sex, number of juveniles, and precipitation levels constant) indicated that variation in adult male and female survival was largely explained by variation in the number of males and females, respectively. Juvenile survival (both males and females) was strongly negatively correlated with juvenile population size but not juvenile body size, adult population size, or total precipitation. Partial correlations revealed that variation in juvenile population size was the single most important factor accounting for variation in male and female juvenile survival, and female age and size at first reproduction. Clutch size and egg size also varied with juvenile population size independent of female body size. At lower juvenile population sizes, female juveniles matured earlier, at a larger body size, and produced larger numbers of smaller eggs than at high juvenile population sizes. Although juvenile body size was positively correlated with male and female reproductive body size and total clutch weight, juvenile fitness traits, in general, were more closely related to variation in juvenile population sizes. Larval traits did not affect adult fitness traits in the terrestrial stage. A nonlinear logistic model best described the functional relationship between juvenile population size and the number of surviving males, females, and total adult biomass. As number of juveniles produced increased, the number of surviving adult males, females, and total biomass plateaued, suggesting that the terrestrial environment limited adult population size. My results demonstrate that density-dependent effects operating in the terrestrial stage may be important in regulating Wood Frog population size.
Free radical theory predicts that the unavoidable production of reactive molecules as a by-product of the respiratory transport chain will pathologically affect organismal function and fitness and lead to disease and a shortened life span. This suggests that free radical production may be linked to metabolic rate, which in turn relates to foraging strategies and intrinsic growth rate and could therefore be important for directing the evolution of life histories. We designed an experiment in which young lizards (Australian Painted Dragons, Ctenophorus pictus) received an implant with α-Tocophorol (Vitamin E) or control vehicle (cocoa butter). They were released into the wild and monitored for survival. Recapture rate was eight per cent for vitamin E-treated lizards and 16 per cent for controls, resulting in no significant difference in probability of being recaptured. We discuss the importance of dose-dependence and context-dependent effects of this supplementation and outline other physiological factors that may be driving mortality rates in young lizards.
A new symphurine tonguefish species, Symphurus megasomus, is described on the basis of 18 specimens collected in deep waters (471–640 m) off eastern Taiwan. This species is characterized by the combination of a predominant 1-2-3-2-2 pattern of interdigitation of dorsal pterygiophores and neural spines, 14 caudal-fin rays, 106–111 dorsal-fin rays, 91–96 anal-fin rays, 55–58 total vertebrae, 5 hypurals, deep body (27.2–30.8% SL), small (5.3–7.9% HL), round and separate eyes, bluish-black opercle and peritoneum on both sides of body (in both fresh and alcohol-preserved specimens), uniformly straw-colored to dark-brown ocular-side background pigmentation without freckles or mottled pigmentation, and uniformly white to light yellow blind side. Among congeners, S. megasomus is most similar to S. undatus, which has the same ID pattern and number of caudal-fin rays, but differs markedly from that species in having more dorsal- and anal-fin rays and in its ocular-side coloration (uniformly straw-colored to dark brown vs. freckles on the ocular side of S. undatus).
Eastern and western populations of the ranid frog Odorrana chapaensis from Vietnam and China are readily differentiated by morphology and mtDNA, and weakly differentiated by morphometrics. The western population contains the type localities of O. chapaensis and its junior synonym Amolops macrorhynchus. The eastern population is described as a new species, characterized by a combination of males with snout–vent length 71–79 mm, females 87–100 mm; head length greater than head width; relative finger length I ≤ II < IV < III; tips of all digits expanded with circummarginal grooves; webbing complete to discs of all toes; posterior portion of thigh yellow-brown with fine, dusty-white stippling; inguinal region brown with indistinct gray-white spotting; females with eggs with pigmented poles; males with gular pouches; and males with spinules on upper lip from snout tip to level of mid-portion of eye. The original description of O. chapaensis is translated into English and supplemented with new data.
Body temperatures of ectotherms critically affect their bioenergetics, and thus have consequences for multiple aspects of population ecology, including recruitment, survival, and population viability. We compared body temperatures and movement between gravid and non-gravid female Timber Rattlesnakes (Crotalus horridus) inhabiting northwestern Arkansas using radiotelemetry. Body temperatures (n = 839) were recorded from six gravid and five non-gravid adult female rattlesnakes using temperature-sensitive radiotelemetry. Mean Tbs were calculated for each hour of the day from 15 July–22 August 2002 and used to construct a representative 24-hour body temperature profile. Gravid females had significantly higher mean Tbs in the early morning and again for most hours in the late afternoon and first half of scotophase. Overall snake Tbs were higher during the day and lower at night. Moreover, gravid females exhibited lower variation in Tb during late afternoon than did non-gravid females. Mean area used (± SD) by gravid females (0.4 ± 0.4 ha) was significantly less than that of non-gravid females (2.4 ± 1.8 ha), and daily movement (18.2 ± 6.1 m/day) and overall distance traveled by non-gravid females (827.4 ± 234.4 m) was over twice that of gravid females (8.8 ± 4.6 m/day; 384.0 ± 236.1 m). Understanding the thermal ecology of reproduction in this viviparous capital breeder provides valuable information for habitat management and species conservation.
Amblyceps protentum is described herein as a new species of amblycipitid catfish from the Salween River drainage in western Thailand. It can be distinguished from Indochinese congeners except for A. kurzii by a more elongate, slender body most evident in the smaller body depth at anus (8.0–11.0% SL vs. 10.7–16.9) and caudal peduncle depth (8.0–10.3% SL vs. 10.1–15.9). It differs from A. kurzii in having a longer adipose-fin base (18.8–22.7% SL vs. 15.1–18.3) and larger eye (diameter 6.9–8.8% HL vs. 5.1–5.8). Amblyceps protentum is further diagnosed by the following combination of characters: predorsal length 24.1–28.9% SL, length of dorsal-fin base 10.5–13.2% SL, dorsal-to-adipose distance 26.3–32.2% SL; head width 12.1–15.0% SL, total vertebrae 41–42, an incomplete lateral line and deeply forked caudal fin with poorly-developed projections on proximal lepidotrichia of median rays. The taxonomic status of A. caecutiens and A. kurzii are discussed and a neotype designated for A. caecutiens. This neotype designation makes A. mucronatum a junior subjective synonym of A. caecutiens.
Understanding the space use patterns of a population may provide crucial information regarding land management decisions, such as delineation of protected areas. Herein we provide a comprehensive analysis of factors affecting the space use of Desert Tortoises in the west Mojave Desert, including physical, social, and environmental variables. Our objectives were to determine how spatial overlap, as well as multiple parameters of burrow use, influence home range size of this species. Male tortoises were significantly larger than females and exhibited very different patterns of space and burrow use; however, body size did not affect these variables. Male home range (100% MCP) and core area (50% MCP) size averaged 65% and 73% larger than those of females. Burrow use by males and females affected core area size, but not home range area. Females exhibited a strong male bias in overlap of both estimates of space use and burrow sharing, while using a significantly lower number of burrows per year. However, males overlapped and shared burrows with a similar number of tortoises of either sex. In addition, a high degree of home range overlap between individuals suggests a lack of territoriality in this population, although this warrants further analysis. These results suggest that social factors may not be the primary determinants of space use in this Desert Tortoise population.
From 2005 through 2008, seven mature female Finetooth Sharks, Carcharhinus isodon, were collected in the central northern Gulf of Mexico between April and June, a time coinciding with parturition and ovulation for the species. Five specimens displayed states of pregnancy and ovarian development consistent with a biennial reproductive cycle. Two individuals had near-term pups and vitellogenic oocytes, a condition indicative of an annual reproductive cycle. These observations are the first report of annual reproduction in Finetooth Sharks and represent the first documented case of intraspecific divergence in the reproductive cycles for any elasmobranch within a discrete area.
Despite known population-level sensitivity to adult vital rates, there is a shortage of robust estimates of adult survival and breeding frequency for pond-breeding amphibians. Evaluating the applicability of metapopulation principles to amphibians has also been constrained by the lack of demographic studies scaled beyond individual breeding populations. We investigate spatial and temporal demographic variability among six proximate breeding populations of Marbled Salamanders (Ambystoma opacum) in western Massachusetts, USA, focusing on the terrestrial adult life stage. Between 1999 and 2004, we captured and photographed approximately 1700 breeding adults, each between one and 12 times, at drift fences encircling breeding sites. After constructing individual capture histories from field data, we applied maximum likelihood approaches to estimate parameters for survival in the pond basins during breeding periods, survival in upland habitat during breeding and non-breeding periods, and both breeding and capture probabilities. Models selected using Akaike's Information Criteria suggested that there was moderate variability in pond survival across years, but that generally, pond and upland survival varied little among populations within years. This suggests that asynchronous variability indicative of metapopulation dynamics is unlikely to be significant in the adult stage, at least among nearby populations in similar upland forests. An integrated measure of annual survival was 0.66 (SE = 0.02) for males and 0.62 (SE = 0.01) for females. Average breeding probabilities were very high (0.96; SE = 0.01) for males and high (0.67; SE = 0.02) for females, resulting in estimates of 2.5 and 2.0 lifetime breeding attempts, respectively. These parameter estimates will be used to develop spatially explicit population models to guide conservation and forest management strategies for A. opacum and other pond-breeding amphibians with similar life histories. Additional empirical work that estimates the effects of alternative management strategies on these vital rates will greatly improve the utility of these models.
The silverside fish tribe Menidiini (Teleostei: Atherinopsidae) consists of four genera, Menidia, Labidesthes, Poblana, and Chirostoma, that are distributed along the Atlantic coast of North America, throughout the Gulf of México, insular United States, and the Mesa Central of México. It has been suggested that Chirostoma, Poblana, and Menidia should be recognized as a single genus under the nominal Menidia. To test this hypothesis, phylogenetic relationships within the tribe Menidiini were assessed using the mitochondrially encoded ND2 gene. Monophyly of the Menidiini tribe was supported. Results also failed to support monophyly for the genera Menidia and Chirostoma as currently recognized. A central Mexican clade, inclusive of Chirostoma and Poblana, was recovered as monophyletic and strongly supported. Relationships within the Mesa Central clade support a previously recognized “humboldtianum” clade and the paraphyly of Chirostoma with respect to Poblana.