The Herpetological Journal

Authors: Downie, J.R.; Sams, K. & Walsh, P.T.

Abstract: The genus Pseudis is unique amongst anuran amphibians in that body growth occurs mostly or entirely in the larval phase, with huge tadpoles metamorphosing into smaller but adult-sized frogs. Selected organ systems were studied in tadpoles of the paradoxical frog Pseudis paradoxa in order to determine whether they have any special features associated with their large size and unique life history. Testes of large tadpoles were well developed with spermatogenesis proceeding before metamorphosis; ovaries were also well developed in later stage tadpoles with large pre-vitellogenic oocytes. In later stage tadpoles, unusually for anuran larvae, the intestine had developed longitudinal internal ridges, increasing the internal surface area. Lungs of later stage tadpoles showed internal septation, again an unusual feature for anuran larvae. Finally, later stage tadpoles had a considerably thickened epidermis compared to earlier stages, though no sign of adult-type glands. Overall, these results suggest that as Pseudis tadpoles grow in size beyond the norm for conventional anuran larvae, a suite of features normally associated with adult anurans begins to develop before metamorphosis.

Keywords: ANURA, TRINIDAD, TADPOLE, AMPHIBIANS

Authors: Downie, J.R.; Ramnarine, I.; Sams, K. & Walsh, P.T.

Abstract: The genus Pseudis is unique amongst anuran amphibians in that body growth occurs mostly or entirely in the larval phase, with huge tadpoles metamorphosing into adult-sized frogs. Tadpole growth rate, metamorphic duration and tadpole habitat were studied in the paradoxical frog Pseudis paradoxa in Trinidad, West Indies, in order to assess the factors which may have led to the evolution of this unique life history. Growth rate was shown to be similar to other tropical tadpoles: Pseudis simply continued to grow, rather than progress to metamorphosis. Metamorphic duration fitted well with a model based on tadpole size. Sexual dimorphism in tadpole size was apparent, with females larger than males at metamorphosis. Pseudis tadpoles initially possess highly cryptic patterning, which is lost as they grow larger. The costs and benefits of continued growth in the larval phase in a permanent tropical swamp habitat are discussed in terms of potential predators and food availability to both Pseudis larvae and adults.

Keywords: AMPHIBIAN TADPOLES, ANURANS, MATURATION, TRINIDAD

pp. 21-27
Authors: Barrionuevo, J.S. & Baldo, D.

Abstract: The tadpoles of two species of the genus Telmatobius (T. platycephalus and T. pinguiculus) from montane regions of Argentina are described. The larvae of both species are characterized by bodies that are oval in dorsal view and depressed in lateral aspect. In each, the snout is rounded in dorsal and lateral profiles; the labial tooth row formula is 2(2)/3(1) and a short, sinistral spiracle is directed posterodorsally. The tadpoles of T. platycephalus are larger than those of T. pinguiculus; they also lack a row of mental submarginal papillae and the nares are dorsally oriented instead of dorsolaterally.

Keywords: EXTERNAL LARVAL MORPHOLOGY, ANURA, MONTANE FROGS, CERATOPHRYIDAE

pp. 29-33
Authors: Casale, Paolo; d'Astore, Paola Pino & Argano, Roberto

Abstract: Growth rate is a fundamental parameter in understanding sea turtle population dynamics and is also important for the conservation of these threatened species. It can be influenced by both environmental and genetic factors, and thus it can vary according to the area. Growth rates and age at size of loggerhead turtles (Caretta caretta) are estimated for the first time in the Mediterranean sea and in particular for the elusive first period of life, through length frequency data from 88 turtles ranging from 6.4 to 30 cm curved carapace length found in Italian waters. A visual examination of the length distribution of small turtles found in pelagic habitats suggests a preliminary growth curve for early juveniles in the Mediterranean. Results indicate that this size range includes turtles in the first four years of life. Growth rates ranged from 11.8 cm/yr in the first six months of life to 3.6 cm/yr at the age of 2.5–3.5 years and are similar to those estimated from the Atlantic. Results also suggest a secondary increase in growth rates in larger turtles recruiting to neritic habitats, supporting a polyphasic growth pattern proposed for other populations and other sea turtle species.

Keywords: ITALY, GROWTH PATTERN, MEDITERRANEAN SEA, POPULATION DYNAMICS

pp. 35-40
Authors: Urbina G., Jenny C. & Galeano, Sandra P.

Abstract: The high proportion of declining amphibian populations and species without ecological information makes it imperative to conduct research on their population biology, natural history and habitat requirements. We describe the abundance, age structure, activity patterns and microhabitat of four populations of Rhinella macrorhina, a threatened toad from the cloud forests of the Andes of Colombia. We found similar abundances in all populations, despite differences in the level of alteration of the forest patches studied. Abundance of the species was higher during the rainy season and was related to leaf litter depth and leaf litter humidity. We found similar proportions of adults and juveniles among seasons in all populations, and we suggest that daily activity of R. macrorhina varies by age class, exhibiting a temporal and spatial segregation. We present insight into habitat alteration which may threaten the species, principally in the Amalfi locality where we report the largest documented population of the species.

Keywords: HABITAT ALTERATION, THREATENED SPECIES, AGE STRUCTURE, ANURANS

pp. 41-48
Authors: Jesus, José; Nagy, Zoltán T.; Branch, William R.; Wink, Michael; Brehm, Antonio & Harris, D. James

Abstract: Mitochondrial sequences (16S rRNA and cytochrome b) of the colubrine snake genera Philothamnus and Hapsidophrys were analysed. Samples were obtained from three volcanic islands in the Gulf of Guinea. The main objective was to infer phylogenetic relationships between the taxa and to trace back the colonization patterns of the group. Both insular species, Philothamnus girardi and Philothamnus thomensis, form a monophyletic unit indicating a single colonization event of one island (probably São Tomé) followed by dispersal to Annobon. Genetic divergence was found to be relatively low when compared with other Philothamnus species from the African mainland, but sufficient to consider the two taxa as distinct sister species. Here we also present evidence on the distinct phylogenetic position of Hapsidophrys sp. from the island of Príncipe, which should be considered as a distinct species, Hapsidophrys principis, a sister taxon of H. smaragdina.

Keywords: 16S RRNA, PHILOTHAMNUS GIRARDI, CYTOCHROME B, HAPSIDOPHRYS PRINCIPIS, GULF OF GUINEA ISLANDS, PHILOTHAMNUS THOMENSIS

pp. 49-52
Authors: Goldberg, Stephen R.; Bursey, Charles R. & Vitt, Laurie J.

Abstract: Plica plica and Plica umbra from Brazil and Ecuador were examined for endoparasites. Plica plica harboured one species of Digenea, Mesocoelium monas, four species of Nematoda, Oswaldocruzia vitti, Physalopteroides venancioi, Strongyluris oscari and Physaloptera retusa; P. umbra harboured five species of Nematoda, Oswaldocruzia bainae, Oswaldocruzia vitti, Physaloptera retusa, Strongyluris oscari and Piratuba digiticauda. Three new host records are reported for P. plica and three for P. umbra. Both lizard species are ant specialists but do eat other types of prey. We speculate on sources of endoparasites based on the diets of these two arboreal tropical lizards.

Keywords: SQUAMATA, TROPIDURIDAE, HELMINTH COMMUNITIES