Claudio Borteiro

Food habits of the Broad‐snouted Caiman (Caiman latirostris: Crocodylia, Alligatoridae) in northwestern Uruguay

The food habits of the Broad‐snouted Caiman (Caiman latirostris) were studied in northwestern Uruguay. The most common prey were insects, the shrimp Pseudopalaemon bouvieri, the snail Pomacea canaliculata, fish and birds. Spiders, crabs, amphibians, snakes, turtles and mammals were consumed less frequently. Arthropods were the most frequent prey for juvenile caiman. Fish and snails were consumed by all size classes. The proportion of stomach contents with invertebrates decreased with increasing caiman size, and that with vertebrates was greater in the diet of larger caiman. Diet composition and ontogenetic shift are similar to that of other crocodilians considered as opportunistic generalist predators. Se estudiaron los hábitos alimenticios del Yacaré (Caiman latirostris) en el noroeste de Uruguay. Las presas más comunes fueron insectos, el camarón Pseudopalaemon bouvieri, el caracol Pomacea canaliculata, peces y aves. Arañas, cangrejos, anfibios, serpientes, tortugas y mamíferos fueron consumidos menos frecuentemente. Los artrópodos fueron las presas más frecuentes de juveniles. Peces y aves fueron consumidos por todos los tamaños. La proporción de contenidos estomacales con invertebrados disminuyó al aumentar el tamaño de los caimanes, y la de vertebrados fue mayor en los individuos de mayor tamaño. La composición y cambio ontogenético en la dieta resultan similares a los de crocodilianos considerados predadores generalistas oportunistas.

Chromosomal Variation in the Species of the Physalaemus henselii Group (Anura: Leiuperidae)

Abstract In this work, we studied chromosome morphology, Ag-NOR, and C-banding patterns in the Neotropical leiuperid frogs that compose the Physalaemus henselii species group: Physalaemus fernandezae, Physalaemus henselii, and Physalaemus riograndensis. The chromosome diploid complement in all species was 2n  =  22 and consisted of seven large to medium and four small chromosome pairs. Chromosome fundamental number (FN) varied, because pair 11 was metacentric in P. henselii and P. riograndensis (FN  =  44) but telocentric in P. fernandezae (FN  =  42). Each species presented a single pair of Ag-NORs, which are located in the secondary constriction of pair 11 in the case of P. fernandezae, in pair 8 in P. riograndensis (as in many other Physalaemus species), and in pair 5 in P. henselii, which is a unique character state among leiuperids. There were no substantial interspecific differences in C-banding pattern, and the heterochromatic bands were mainly located in the centromeric regions of all chromosomes. Noncentromeric C-bands adjacent to NORs were detected in P. riograndensis and P. fernandezae, as already reported for other species of this genus. The karyotype of P. fernandezae was quite similar to that of species in the P. signifer group and of the leiuperid Eupemphix nattereri. Neither karyotypic data nor adult and larval morphology support the P. henselii species group as currently defined.

The Identity of Eupemphix fuscomaculatus Steindachner, 1864 (Amphibia: Anura)

Abstract Eupemphix fuscomaculatus Steindachner, 1864 was described on the basis of a single specimen collected at Caiçara, Mato Grosso, Brazil. This species, currently included in the genus Pleurodema, experienced a confusing taxonomic history and is supposedly known only from the holotype and seven specimens from Río Apa, Paraguay, collected by Alfredo Borelli in 1893–1894. Examination of Steindachners holotype and Borellis specimens revealed that they are not conspecific, E. fuscomaculatus is a junior synonym of Physalaemus biligonigerus (Cope, 1861 “1860”), and the specimens from Río Apa, Paraguay, could not be distinguished by their morphology or ploidy either from Pleurodema bibroni or P. kriegi, and are referred here as Pleurodema bibroni based on ecological considerations. Contrary to a recent proposal, the presence of vomerine teeth is not considered diagnostic for the genus Pleurodema, as they are absent in seven of the 13 species of Pleurodema examined. In addition, we propose to amend the type locality of P. biligonigerus to the surroundings of La Paz, Entre Ríos Province, Argentina.

Chytridiomycosis in frogs from Uruguay.

Amphibian chytridiomycosis caused by Batrachochytrium dendrobatidis is reported in Uruguayan native amphibians for the first time. Histological evidence of infection was observed in tadpoles of Hypsiboas pulchellus, Odontophrynus maisuma, Physalaemus henselii, and Scinax squalirostris. The effects of chytridiomycosis on these species are still unknown. However, the disease is of potential concern for the conservation of the apparently declining species P. henselii and also for O. maisuma, given its restricted distribution in habitats which are being increasingly disturbed.

Reptilia, Gekkonidae, Hemidactylus mabouia, Tarentola mauritanica: Distribution extension and anthropogenic dispersal

, were reported as capable of displacing native ones (Hanley et al. 1998, Dame and Petren 2006, Rivas Fuenmayor et al. 2005). Interestingly, human related translocations aided some of these invasive lizards to have currently an almost cosmopolitan distribution in tropical and temperate regions (Vences et al. 2004, Carranza and Arnold 2006). Two of these vagile species are

The tadpole of Scinax aromothyella (Anura: Hylidae) from Uruguay

We describe the tadpole of Scinax aromothyella from the surroundings of Quebrada de los Cuervos, Departamento de Treinta y Tres, Uruguay. It shares with other larvae of the Scinax catharinae clade the slightly depressed body, a dextral vent tube that reaches the free margin of the ventral fin, and the oral disc with a dorsal gap in the marginal row of papillae and with a concave posterior edge. It is most similar to the tadpole of Scinax berthae, from which it differs in the larger total length of S. aromothyella. Describimos la larva de Scinax aromothyella de los alrededores de la Quebrada de los Cuervos, Departamento de Treinta y Tres, Uruguay. Comparte con las larvas de otras especies del clado de Scinax catharinae el tener el cuerpo levemente deprimido, el tubo proctodeal dextro que alcanza el borde libre de la aleta ventral, y el disco oral con un claro rostral en la hilera de papilas marginales y con su borde posterior cóncavo. Es muy parecida a la larva de Scinax berthae, de la que difiere en la mayor longitud total de S. aromothyella.

Conservation status assessment of the amphibians and reptiles of Uruguay

The native species of amphibians and reptiles of Uruguay were categorized according to the IUCN Red List criteria. Out of 47 amphibian species, seven are listed as Critically Endangered (CR), five as Endangered (EN), one as Vulnerable (VU), three as Near Threatened (NT), and two as Data Deficient (DD); the remaining species are considered to be Least Concern (LC). Among the 64 species of reptiles evaluated, one is listed as Critically Endangered (CR), seven as Endangered (EN), two as Vulnerable (VU), one as Near Threatened (NT) and seven as Data Deficient (DD); the rest are considered to be Least Concern (LC). The use of these results as an additional criterion in the definition of protected areas in Uruguay will contribute towards the conservation of the aforementioned threatened species and their associated ecosystems.

The Tadpole and Karyotype of Rhinella achavali (Anura: Bufonidae)

Abstract We describe the external morphology, buccal cavity, chondrocranium, hyobranchial skeleton, and musculature of the tadpole of Rhinella achavali (Achavals Toad), along with its karyotype. Tadpoles were found in a small, permanent stream and were showing schooling behavior. The characterization of the proposed species groups within Rhinella cannot be currently improved using external larval morphology, as it seems to be much conserved within this genus. Buccal cavity morphology confirms the distinctiveness of the Rhinella veraguensis (Veragua Toad) group with respect to other known Rhinella. Musculoskeletal character states are similar among bufonids, although within this family the basal genus Melanophryniscus shows some distinctive states. The karyotype is composed of 22 bi-armed chromosomes, with secondary constrictions in pair 7, as found in the other species in the Rhinella marina (Marine Toad) group.

A Cytotaxonomic Survey of the Genus Melanophryniscus Gallardo, 1961 (Anura: Bufonidae)

Abstract We present a cytogenetic survey of the basal bufonid genus Melanophryniscus that covered 14 of the 25 species currently recognized, representing the three phenetic species groups: M. moreirae, M. stelzneri, and M. tumifrons. All species presented a diploid chromosome complement constituted by 11 bi-armed chromosome pairs (2n  =  2x  =  22; FN  =  44). Some remarkable differences were observed between species groups: chromosome pair 4 was metacentric in species of the M. tumifrons group (also with a distinctive C-positive block) but submetacentric in the M. stelzneri group and M. sanmartini (M. moreirae group); pair 5 was submetacentric in M. sanmartini and metacentric in the rest. Chromosome secondary constrictions and silver-stained nucleolar organizer regions were located either in pair 5, 7, or 8 in the M. tumifrons group, M. sanmartini and M. krauczuki (M. stelzneri group), and M. stelzneri group, respectively; and pair 7 was relatively larger in M. sanmartini and M. krauczuki. Studied cytogenetic characters support the M. tumifrons group and suggest a close relationship between M. krauczuki and M. sanmartini. These results call for a reassessment of species relations within Melanophryniscus under an inclusive phylogenetic study.

Amphibia and Reptilia, Quebrada de los Cuervos, Departamento de Treinta y Tres, Uruguay

We present an annotated list of the herpetofauna at the Protected Area Quebrada de los Cuervos, Departamento de Treinta y Tres, Uruguay. We recorded 24 species of amphibians and 29 of reptiles, accounting for near half of the species already reported from Uruguay. New records of Dendropsophus minutus (Hylidae) and Liophis almadensis (Colubridae) are presented, being the southernmost known for these species. Additionally, Melanophryniscus sanmartini (Bufonidae), Anisolepis undulatus (Polychridae), Crotalus durissus terrificus (Viperidae) and Xenodon histricus (Colubridae) are cited for the first time for the Departamento de Treinta y Tres.