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A new species of Bolitoglossa is described from the Cordillera Central of central Panamá. This is a large black species, which is likely related to the B. (Eladinea) schizodactyla group of Costa Rica and Panamá. The new species, known from a single specimen, differs from other large black Bolitoglossa in having white pigmentation on the lower face and on the ventral portions of the head and chest. It also has more interdigital webbing than most members of the B. (E.) schizodactyla group.
Several populations of large (adult standard length, 43–134 mm) black salamanders of the widespread neotropical genus Bolitoglossa (Plethodontidae) are known from the cordilleras of western Panamá and Costa Rica. These populations constitute at least seven species, including two recently described (B. anthracina, B. copia), one described long ago that remains poorly known (B. nigrescens), and three described herein as new. The long-recognized, wide-ranging B. robusta, which is distinguished by a pale, pigmented ring around the tail base and a unique combination of maxillary and vomerine tooth counts, may occur sympatrically with four of the other taxa. Differences in head and body form, adult size, cranial osteology, and maxillary and vomerine tooth counts separate all recognized taxa from one another. These results confirm and indeed increase the exceedingly high diversity of salamander species known from the Cordillera Talamanca-Barú of Costa Rica and Panamá, diversity that now rivals that found anywhere else in the tropics.
The deep-sea ceratioid anglerfish genus Acentrophryne is revised on the basis of all known material. Two species are recognized: the type species Acentrophryne longidens, represented by two specimens collected in the Gulf of Panama and from off the Pacific coast of Costa Rica and a new species described here on the basis of three specimens, all from off Peru. The new species differs from A. longidens in having a much longer distal escal appendage, a longer illicium, a narrower head, and fewer pectoral-fin rays. Diagnoses and descriptions are given for all taxa and a key to the species is provided.
We describe the adult and larval morphology, advertisement call, ecology, and life history of a new species of Marbled Toad from the dry deciduous forests of western Madagascar on the basis of eight specimens from Kirindy Forest C. F. P. F. in the central Menabe area. Scaphiophryne menabensis n. sp. is larger, but morphologically similar to S. marmorata from the eastern rainforests. However, DNA sequence analysis of the mitochondrial 16S rRNA gene resulted in a clear differentiation from this species. The strongest mitochondrial affinities are with S. madagascariensis, a morphologically highly divergent species occurring in montane savanna and forest areas on the high plateau of Madagascar.
A new species of heterodontiform shark is described from three specimens collected in the Gulf of Masira, Central Oman, at a depth of 72 m. A member of the genus Heterodontus, it differs from the eight currently recognized congeners in having four dark saddles distributed more or less equally along the head and body, relatively small, darkly pigmented dorsal fins, each with a white distal streak, large pectoral fins, and a unique egg case, with two long tendrils extending from its base and flanges with two turns.
A field experiment was conducted to test the hypothesis that the plethodontid salamander Ensatina eschscholtzii xanthoptica benefits from aposematic coloration. Under field conditions, clay models painted to resemble E. e. xanthoptica were attacked significantly less often than models lacking the supposed aposematic colors. In addition, the head region of models was attacked significantly more frequently than random, suggesting the models were perceived as prey items. These results are consistent with the hypothesis that E. e. xanthoptica is a mimic of highly toxic Pacific Newts in the genus Taricha. The significance of the E. e. xanthoptica phenotype for the ring species biogeographic scenario and future research directions are briefly discussed.
Jupiaba poekotero, new species, is described from the Rio Tiquié, a tributary of the Rio Uaupés, in the upper Rio Negro system, estado do Amazonas, Brazil. It is distinguished from its congeners by the presence of an unpigmented, horizontally-oriented, roughly oval area on the proximal portion of the caudal-fin lobes, bordered posteriorly by dark pigmentation. Comments on the putative relationships of the new species are provided.
Huia absita, new species, is described from Xe Sap National Biodiversity Conservation Area, southern Laos. Huia absita very closely resembles H. masonii, a species endemic to the Indonesian island of Java about 2,500 km away. The description of the holotype of H. masonii is expanded. Huia absita differs from H. masonii by having an outer metatarsal tubercle, having the third and fifth toes equal in length, and having supernumerary tubercles on the fingers. Huia melasma, new species, is described from Tham Tarn Lot (= Chalerm Rattanakosin) National Park and Kaeng Krachan National Park, western Thailand, and is distinguished by having males with SVL 53.5–55.1, no visible pineal body, a black spot on the side of the snout separated from the black canthal streak extending from nostril to eye, the first and second fingers equal in length, and all toes webbed to base of discs. The description of H. absita and H. melasma brings the number of species of Huia from five to seven.
Puntius tiantian is described from Putao in northernmost Myanmar, diagnosed by having a dark vertical bar anteriorly on the side, a dark blotch on the caudal peduncle, slender and weakly serrated last unbranched dorsal fin ray, and complete lateral line. Puntius didi is described based on material from Myitkyina and Indawgyi Lake. It is similar to P. tiantian in color pattern, but possesses a thicker and more strongly serrated last unbranched dorsal fin ray, and a shorter lateral line perforating only 6–10 scales. The single record of P. phutunio from Myanmar most likely represents misidentified P. didi.
To evaluate the monophyly of Cottus and to identify species groups within the genus we generated a data set of 1914 base pairs of mitochondrial DNA (cytochrome b and ATPase 8 and 6) for 87 individuals representing 36 of the 42 currently recognized species of the genus. Both parsimony and Bayesian analyses consistently supported non-monophyly of Cottus with respect to the Baikalian sculpins and the genus Leptocottus. Analyses also supported recognition of five clades within the genus Cottus. These are referred to herein as the Cottopsis, Uranidea, Baikalian, Cottus, and Cephalocottus clades. These clades encompass all but ten recognized Cottus species, nine whose placement was uncertain in our analyses and one not included in our analyses. Lastly, we recognize a freshwater sculpin clade comprising the most speciose freshwater component of the family Cottidae.
We describe a new species of Albericus from Mt. Shungol in the Herzog Mountains at the north end of the Owen Stanley terrane of Papua New Guinea. The new species differs from all other known species of the genus in its rapid peeping call and in having the tympana hidden in males. It can be further distinguished from particular congeners in a variety of morphometric variables. The new species inhabits lowland hill forest, was moderately common where found, and is only known from the slopes of Mt. Shungol.
Analysis of mtDNA sequence variation (2,548 bp from ND2, cytb, and part of the control region) indicates that the genus Cyprinodon began diverging in the Late Miocene from a common ancestor with Megupsilon, a monotypic genus on the Mesa del Norte of Mexico. The geographic pattern of mtDNA variation, with estimates of divergence time, suggests that by the end of the Miocene Cyprinodon occurred from the Atlantic Coast and West Indies to near the western margin of North America via ancestral Rio Grande and Colorado River systems. Phylogeographic structure within the major mtDNA complexes supports a variety of hypotheses from geology and previous phylogenetic analyses for Late Neogene connections among basins in southwestern North America now separated by formidable barriers to dispersal. Comparison of the mtDNA tree with previous phylogenetic inferences from allozymes indicates that reticulate evolution involving divergent lineages probably was important in the history of Cyprinodon.
Complete mitochondrial DNA cytochrome b gene sequences from 56 specimens representing all 12 species of Lepomis were used to examine phylogenetic relationships within the genus. Results supported the monophyly of Lepomis and all previously recognized subgenera, except Eupomotis, but there was no support for previously proposed relationships among subgenera. Seven species were recovered as monophyletic lineages, while five species (L. auritus, L. macrochirus, L. marginatus, L. miniatus, and L. symmetricus) were recovered as either poly- or paraphyletic or were placed as parts of unresolved polytomies with other species. Parametric bootstrapping tests rejected monophyly for only two of the five species (L. auritus and L. symmetricus). Without additional data, including increased geographic sampling and a comparable nuclear gene phylogeny, it is not possible to determine whether the failure to support monophyly for these two species reflects the presence of cryptic species or results from hybridization.
Evolution of phenotype and mode of speciation were examined for 19 Coregonus populations within and among eight lakes in the Central Alpine region of Europe. These populations reflect a mosaic of morphological, ecological, and life history traits, and thus represent numerous forms (qualitatively described according to relative body size and ecology). Each population had been previously evaluated for six microsatellite DNA loci, and herein for five meristic counts, four fin pigmentation characters, three body color variables, three measures relating to spawning ecology, an estimate of breeding tubercles, and average weight (= size). The two matrices (genotype vs. phenotype/ecology) were then tested for significance amongst themselves, and against evolutionary and geographic models. Microsatellite data associated significantly with a species flock model in which in situ diversification occurred from a common ancestor in each lake or cluster of neighboring lakes. However, phenotype/ecology associated significantly with a model invoking multiple invasions of lakes by pre-existing forms. The latter supports historic perspectives on the evolution of Central Alpine Coregonus and suggests forms within lakes have adapted to specific within-lake environmental niches that are replicated across lakes. This convergence of form and function has long clouded an understanding of coregonine biodiversity, and we suggest it represents a homoplasious condition (i.e., a similarity due not to genealogy but to iteration). This compendium of homoplasious and homologous characters is actually quite unique in nature, and the evolutionary diversification of Central Alpine Coregonus can now be evaluated according to the relative contribution of each character type.
The morphological diversity of Malawi and Tanganyika cichlids has often been qualitatively described, but rarely have hypotheses based on these descriptions been tested empirically. Using landmark based geometric morphometrics, shapes are analyzed independent of other aspects of the body form (e.g., size). The estimation of shape disparity, the quantitative measure of the variance of these raw shapes, can then be applied in order to objectively test hypotheses about morphological diversity. The shape disparity within and between different groups is explored as well as how it is partitioned within the cichlid body. Tanganyika cichlids are found to have significantly greater shape disparity than Malawi cichlids. Ectodini is found to have significantly greater shape disparity than other Great Lake tribes. Piscivorous cichlids are significantly more disparate in shape than cichlids with other diets, and the shape disparity of the cranial region was significantly greater than that of the post-cranial region.
Myxine jespersenae n. sp., described from the North Atlantic Ocean, occurs on the continental slopes off western Greenland and southern Iceland, at depths between 752 and 1556 m. It is diagnosed by a combination of two characters: two paired, pointed, or comb-shaped, bilaterally symmetrical nasal-sinus papillae with 2–5 distal fringes and two cusps fused at their bases in each teeth row. It is further characterized by the following combination of characters: 6 gill pouches; cusps totaling 38– 44; coloration dark grayish brown with a white head, the white extending in a mid-ventral stripe of varying length; body slender (e.g., depth over cloaca 2.9–4.3 %TL); slime pores totalling 107–121. Myxine jespersenae n. sp. replaces the sympatric, but shallower occurring, M. glutinosa Linnaeus, 1758 on the Greenland-Iceland middle continental slope. Myxine glutinosa is here reported from East Greenland waters for the first time.
Bryconamericus turiuba, new species, is described from the upper Rio Paraná system in Brazil. It differs from all congeners in the following combination of characters: 15– 20 branched anal-fin rays; four or five scales in a transverse series from the dorsal-fin origin to the lateral line; shallow body (depth 23.6–30.6% of SL); 37–43 perforated lateral line scales; first, third, and fifth or, more rarely, first and fourth outer premaxillary tricuspid teeth projecting anteriorly; two to five tricuspid to pentacuspid maxillary teeth; dentary with three or four tricuspid or pentacuspid large teeth, followed by five to seven smaller conical to tricuspid teeth; a conspicuous dark, vertically elongate humeral spot, extending to below the lateral line; a dark dorsal stripe extending from the supraoccipital spine to the caudal peduncle with a gap at the adipose-fin base; caudal-fin lobes without conspicuous markings, uniformly pigmented along rays; mature males lacking hooks on the pelvic- and anal-fin rays. The new species is compared with the Bryconamericus species described from the basins of the Rio Paraná, Rio Paraguay, Rio São Francisco, and coastal Brazilian rivers.
The Kemp's Ridley (Lepidochelys kempii) is one of the most endangered sea turtles in the world, and it possesses temperature-dependent sex determination (TSD). Sex ratios produced under TSD can vary widely and can affect the reproductive ecology of a population. Therefore, sex ratios produced from TSD are of ecological and conservation interest. The current study validated and utilized a testosterone radioimmunoassay (RIA) to examine the sex ratio of juvenile Kemp's Ridleys inhabiting the waters near Steinhatchee, Florida. Testosterone levels were measured in blood samples collected from juvenile Kemp's Ridleys captured over a three-year period. Results of this study indicate that a significant female bias (approximately 3.7:1) occurs in the aggregation of juvenile Kemp's Ridleys inhabiting the waters near Steinhatchee.
Riparian areas alone are often insufficient for preservation of riparian taxa. Case studies on many vertebrate taxa have addressed the importance of establishing buffer zones around riparian habitats. The goal of this investigation was to build upon previous studies and assess the relative importance of buffer zones to riparian snakes. A case study was conducted on a Cottonmouth (Agkistrodon piscivorus leucostoma) population within a stream/riparian habitat. Using radio-telemetry, I examined the spatial distribution of males, gravid females, and non-gravid females. Although 83% of all snake observations were within 10 m of the stream, population subunits exhibited different patterns of spatial use. Gravid females provided most of the distant observations, inhabiting the surrounding terrestrial habitat up to 94 m from the shoreline. Thus, disturbances to terrestrial areas surrounding the riparian habitat would likely have the greatest impact on gravid females. These results further establish a need for buffer zones around riparian ecosystems, and highlight the importance of considering spatial use differences between population subunits when outlining buffer zone applications for conservation management.
In anurans, mate choice is traditionally considered to be exercised exclusively by females. Recent studies have, however, pointed out, that male mate choice might occur in a wider array of frog species than previously thought. Theory predicts that male mate choice is likely to be present in a species if female fecundity is related to body size and where time invested into one mating is relatively large. We investigated male mating preferences in Rana dalmatina, a species where both assumptions were likely to be met. Although fecundity was positively correlated with size in females and amplexus does seem to last relatively long, there was no male mate choice for larger females. We discuss these results considering costs and benefits of mate choice and speculate that adaptations to male-male competition and avoidance of heterospecific matings with co-occurring, larger Bufo bufo females may have shaped the evolution of non-choosiness in R. dalmatina males.
We estimated genetic diversity in cave (hypogean) and surface (epigean) populations of the Mexican Tetra, Astyanax mexicanus, using RAPDs and microsatellites. By either measure, genetic diversity was significantly lower in hypogean than in epigean populations, although there was considerable variability in both classes. We examined three factors potentially influencing genetic diversity among hypogean populations: relative population size, cave isolation, and the presence of eyed fish in the cave. Of the three, only the presence of epigean forms within the caves correlated with increased genetic diversity in cave populations. This suggests that increased genetic diversity of A. mexicanus cave populations reflects introgression of alleles from surface populations. Estimation of migration rates among populations using microsatellites supported this conclusion and also suggested that alleles can move among cave and surface populations more easily than from cave to cave.
The relationship between egg size and composition (relative amounts of lipid, protein, and water) can play an important role in determining neonate size, quality, or the amount of post-hatching care observed in many reptiles. We evaluated the relationship among egg wet mass, non-polar lipid mass, water content, shell dry mass, and lean dry mass within and among seven clutches of the Diamondback Terrapin, Malaclemys terrapin, from Chesapeake Bay. Egg size varied considerably among clutches, but was relatively uniform within clutches. Non-polar lipid mass, lean dry mass, and water content correlated positively with egg wet mass indicating that larger eggs contain a proportionally greater amount of these components. There was no relationship between egg wet mass and shell dry mass. Clutches had similar, positive slopes but different intercepts in the relationships between lean dry mass and lipid mass and between water content and total dry mass. Thus, clutches differed in the relative proportions of resources but had similar allocation patterns of egg components. Our data cannot resolve whether these effects are due to differences in resource availability or differences in the physiological mechanisms involved in egg provisioning.
In all vertebrates, responses to environmental perturbation are regulated to at least some degree by glucocorticoid hormones (GCs). In amphibians, GCs, along with several other hormones, also play an important role in larval growth and development preceding metamorphosis. Given these two well-established functions, GCs might be expected to have a role in the well-documented effects that environmental stressors can have on larval amphibian growth and development. However, while treatment with exogenous corticosterone (the main GC in amphibians) can alter growth and development in larval anurans, few studies have addressed the question of whether corticosterone levels achieved in the treatment are representative of levels in amphibians in the field. In this study, we examined physiological levels of corticosterone in Pacific Treefrog tadpoles (Hyla regilla) using a confinement stress protocol in the field and then examined the effects of exogenous corticosterone on growth of treefrog tadpoles in the laboratory. We found that treefrog tadpoles in the field did respond to confinement with increasing corticosterone levels. In addition, treatment with corticosterone in the laboratory resulted in decreased growth. However, the levels of corticosterone in our laboratory treated tadpoles were outside the range of what we have observed in wild animals. Although it is possible that these levels are still in the physiological range, they would be on the high end of what is observed in the field. We suggest that to understand the impacts of environmental stressors on larval amphibians via hormonal mechanisms, we must learn more about what the natural ranges of these hormones are in amphibians developing in the field.