Evaluation of sperm quality of Erythrolamprus poecilogyrus sublineatus (Cope, 1860) (Serpentes, Dipsadidae)

Erythrolamprus poecilogyrus sublineatus (Cope, 1860), is a species widely distributed in the Pampa Domain, occurring in Rio Grande do Sul, Argentina and Uruguay, mainlyin the pampa region. In the coastal region of southern Brazil this is serpent is considered one of the most abundant. The purpose of the present study is to describe the techniques of sperm evaluation in vitro for E. poecilogyrus sublineatus in the coastal plain of Rio Grande do Sul, Brazil. After laparatomy the efferent vases were collected and the semen was diluted in 1ml Beltsville Thawing Solution. The characteristics of motility, membrane integrity, mitochondria, acrosome, DNA, cell viability and cellular functionality were evaluated. Fluorescent probes were used for the evaluation of sperm structure in epifluorescence microscope. With the techniques described, it was possible to identify intact and injured cells, enabling the determination of cell characteristics for the spring season (October and November). It was observed in the analyses that 80% of sperm cells were mobile and that 84.1 ± 8.0% of sperm membranes were intact. The standards found were of 48 ± 13.8% of intact acrosome, 73.6 ± 6.0 of perfect DNA and of 91.8 ± 4.0 of functional mitochondria. Thus, these values from the sperm analysis can be used as standards for the species Erythrolamprus poecilogyrus sublineatus.

First record of the Lesser Snouted Treefrog Scinax nasicus (Cope, 1862) in Brazilian coast and new species records for the state of Rio Grande do Sul

Herein, we provide new occurrence records of Scinax nasicus (Cope, 1862) for the state of Rio Grande do Sul, Southern Brazil. All new records here provide are located on Southern half of the state. Besides this, we provide the first record for species in Brazilian coastal zone. Those records improve considerably our knowledge regarding species distribution in Southern Brazil.

The recognition of Dendropsophus minusculus (Rivero, 1971) (Hylidae, Dendropsophini) as a highly polymorphic, multi-domain distributed species

Herein we present new occurrences of sites of Dendropsophus minusculus in Brazil adding information about reproductive biology and colour patterns of the species. Such information is fundamental for characterising the species that we believe has been neglected due to its morphological similarity with other congeneric species. Dendropsophus minusculus may be found in different morphoclimatic domains, being one of the most generalist species of the genus in this aspect. The species plasticity is not restricted to its occurrence, but also related to aspects of its reproductive biology, and we hypothesised that the latter feature could explain the wide geographical range of the species. We highlight the importance of further in-depth studies and the use of D. minusculus as a model to understand the historical events responsible for the current geographical distribution of the morphoclimatic domains in Brazil.

The activity patterns and microhabitat use of Pseudis minuta Günther, 1858 (Anura, Hylidae) in the Lagoa do Peixe National Park, a biosphere reserve of the brazilian subtropics

Pseudis minuta is abundant in a variety of aquatic environments of the Pampa domain. Therefore, it can be considered a good model for testing hypotheses on environmental heterogeneity and the influence of climate on the activity of anurans. In this study, we examined the spatial distribution pattern of P. minuta in terms of microhabitats and the influence of abiotic factors on seasonal fluctuations in the abundance of this species. Samples were collected monthly from April 2008 to May 2009 in wetlands and coastal dunes in the Lagoa do Peixe National Park. A total of 112 specimens of P. minuta were collected, of which 45 were found in the wetland area and 67 in the dune area. The species showed seasonal fluctuation in abundance, and it was most abundant in months with higher temperatures (spring-summer). Pseudis minuta was mainly associated with aquatic vegetation, an expected pattern in terms of their morphological adaptations to this environment. Among the abiotic parameters analyzed, only the monthly mean temperature showed a significant correlation (p < 0.05; r = 0.67) with the abundance of P. minuta. We concluded that P. minuta is a generalist species with respect to microhabitat use and also that fluctuation in its population abundance is mainly associated with seasonal variation in temperature.