Reproductive Strategies of Brazilian Lizards of the Genus Tropidurus Rodrigues, 1987 (Squamata, Tropiduridae) in the Temporal and Spatial

Abstract

Estrategias Reproductivas de las Lagartijas Brasileñas del Género SUMMARY:Reproductive strategy is the set of adaptations that promote the most efficient way that the species will survive under the particular conditions of a determined environment. Understanding these adaptations is important and can help pinpoint populations indicator of environmental changes. Spermatogenesis is a measurable biological process of these adaptations in spatial and temporal scales. We analyzed the morphology of the testes and oviducts of the lizard species that comprise the genus Tropidurus, taking into account the geographical distribution and sympatric relations. For the analysis and the testes were removed from the middle part of the oviducts from Tropidurus etheridge, T. oreadicus, T. itambere, T. spinulosus and T. Guarani species, collected in different places in the Mato Grosso state, Brazil. The reproductive period is synchronous for males and females and occurs in September, October and November. Reproductive males were characterized. In the testes are seminiferous tubules with germ cells at different stages of spermatogenesis, with a high epithelium, at present light, free spermatozoa in the lumen and reduction of interstitial tissue. For females, the reproduction peak occurs when the oviduct epithelium is high with secretions and basal nucleus. These months are characterized in the sampled areas over a period of heavy rain and high temperatures. The decline of reproductive period was observed in both sexes, between April and August. Low reproduction in males is characterized by ample light, absence of sperm, only germ cells in the early stages of spermatogenesis are observed (a few spermatogonia and spermatocytes) and interstitial tissue wide. In females, the period of reproductive decline is marked by the absence of unicellular glands in the oviduct epithelium, with higher affinity with the dye. This period corresponds to low rainfall periods and lower temperatures. We propose an analysis of zoological samples; this is a proposal to facilitate the work of many researchers through access to the species, especially rare species.

Germinative cells and spermatogenesis of the lizard Tropidurus torquatus (Tropiduridae) from a urban area in the cerrado biome of the brazilian midwest

“…However, the relationship between the types of germinative cells and the size of seminiferous tubules showed differences of spermatogenic activity, with all types of germinative cells present, but with regression during February to April (FERREIRA et al, 2009). For T. oreadicus from the Cerrado Biome, spermatogenesis was more intense during the months of June to September, during the dry season (MEIRA et al, 2007;FERREIRA et al, 2011). Another species of the Cerrado, T. montanus, presented reproductive males throughout the year, but in greater proportion from September to January ( VAN SLUYS et al, 2002).…”

“…The gonadosomatic ratio (GR) was obtained using the ratio of the weight of the right testicle and the lizard weight for each individual sampled. After this evaluation, samples of the right testis and epididymis were submitted to a histological protocol adapted by FERREIRA et al (2011), for light microscopy. Subsequently, the samples were embedded in methacrylate plastic resin and sectioned with 3 µm thickness at intervals of 30 µm between sections.…”

Biologia reprodutiva de três espécies simpátricas de lagartos da família Gymnophthalmidae na região das Dunas do Rio São Francisco, BA

“…A estratégia reprodutiva é o conjunto de adaptações que promove a forma mais eficiente de uma população sobreviver sob condições particulares de um determinado ambiente (Ferreira et al, 2011). Aspectos reprodutivos sofrem influências de condições ambientais (Fitch, 1970), da história filogenética do grupo (Garda et al, 2012;Orofino, et al, 2010;dos Santos, 2013) ou da somatória dos dois (Brown & Shine, 2006;Dunham & Miles, 1985;RamosPallares et al, 2010) e é necessário o acúmulo de informações de diferentes táxons e de diferentes localidades, para realizar comparações intra e interespecíficas, que auxiliam na definição de quais são os fatores de maior influência nos padrões reprodutivos de um dado grupo (Ferreira et al, 2011).…”

“…Essas alterações não apenas funcionam como caracteres qualitativos na análise dos padrões reprodutivos de diferentes organismos, como estão envolvidas no sentido de promover a maneira mais eficiente de uma população sobreviver sob determinadas características ambientais (Ferreira et al, 2011;Tinkle et al, 1969).…”

“…Historicamente, o padrão de atividade reprodutiva em Squamata tem sido associado com fatores ambientais limitantes, sendo o fotoperíodo e a temperatura os mais importantes na definição do ciclo reprodutivo de espécies de zonas temperadas (Ferreira et al, 2009;Ferreira et al, 2011). A influência destes fatores pode ser testada através da investigação das estratégias reprodutivas de espécies de ampla distribuição que apresentem populações em habitats sujeitos a condições ambientais distintas (Ferreira et al, 2011;Garda et al, 2012).…”