Reprodução de Pseudis minuta (Anura, Hylidae) no sul do Brasil

Abstract

Reproduction of Pseudis minuta (Anura, Hylidae) in southern Brazil. This study was based on individuals of Pseudis minuta captured or observed in the municipality of Candiota, Campanha region of the state of Rio Grande do Sul, southern Brazil. Sampling occurred along ten non-consecutive months in 2000, 2001 and 2002. The reproductive phases were characterized based on the gonadal development stage of 39 males and 50 females, and on the observation, in nature, of the seasonal distribution of calling males, occurrence of amplectant pairs, and presence of larvae, juveniles and adults. Calls were recorded from August to April, amplectant pairs from October to February (except January), tadpoles from October to March (except February), and juveniles in all the sampled months (except January). Reproductive activity was not observed in late fall and early winter, even though females with post-vitellogenic oocytes and males with spermatozoa in the seminiferous tubules were recorded in all the seasons. Mature females were statistically larger and heavier than mature males. The smallest female with post-vitellogenic oocytes had 32.0 mm of snout-vent length, and the smallest male with spermatozoa in its seminiferous tubules had 20.6 mm. The number of post-vitellogenic oocytes was directly proportional to the mass and to the snout-vent length of females, and the length of testis was directly proportional to the snout-vent length and to the mass of males.

Spatial and temporal distribution of Pseudis minuta (Anura, Hylidae, Hylinae) and environmental variables related to its reproductive activity in Reserva Biológica do Lami, southern Brazil

“…Records of greater number of individuals, callings and mainly of amplexi from August to November indicate that the species has prolonged seasonal reproductive activity in the study area, as observed in other regions (LAVILLA & ROUGÉS, 1992;LANGONE, 1995;MELCHIORS et al, 2004). Taking into consideration that spermatozoa and mature ovums are present all over the year (LAVILLA & ROUGÉS, 1992;MELCHIORS et al, 2004), the reproduction of the species seems to be actually conditioned by extrinsic factors, like formerly suggested by MELCHIORS et al (2004).…”

“…Taking into consideration that spermatozoa and mature ovums are present all over the year (LAVILLA & ROUGÉS, 1992;MELCHIORS et al, 2004), the reproduction of the species seems to be actually conditioned by extrinsic factors, like formerly suggested by MELCHIORS et al (2004). The strong influence of the temperature, relative humidity and rainfall, either on the presence of individuals or on the calling activity of males, reinforces this evidence.…”

“…CARDOSO et al, 1989;ANDRADE & CARDOSO, 1991;POMBAL, 1997;BERTOLUCI & RODRIGUES, 2002;TOLEDO et al, 2003;MELCHIORS et al, 2004). However, few studies assess spatial and temporal distribution of females and juveniles and study synchrony and chronology of events that happen in periods other than the reproductive season (see CAMARGO et al, 2005).…”

“…Individuals were considered mature as follows: males with SVL from 20.6 mm and mass from 1.3 g; females with SVL from 32.0 mm and mass from 4.4 g (MELCHIORS et al, 2004).…”

Seasonality in anuran activity and calling season in a Brazilian subtemperate wetland

“…This result suggests a certain plasticity of the species regarding seasonality and reproductive activity. Such plasticity also appears to occur in P. minuta, whose reproductive activity was previously identified as brief or long (Langone 1994;Melchiors et al 2004). The low values of niche overlap reinforce the potential of the entire community to keep calling through all the year.…”