Morfometria testicular durante o ciclo reprodutivo de Dendropsophus minutus (Peters) (Anura, Hylidae)

Abstract

Este estudo descreve o ciclo reprodutivo de machos de Dendropsophus minutus (Peters, 1872) com base na análise da morfometria testicular e a correlação com parâmetros climáticos. Cinqüenta indivíduos foram coletados em São José do Rio Preto, São Paulo. Após as análises macroscópicas, os testículos foram encaminhados à rotina histológica, fixados com Bouin e incluídos em historesina. Cortes de 2 µm foram corados com azul de toluidina 1% e observados ao microscópio. Testículos de D. minutus são órgãos pequenos (comprimento 1,90 ± 0,13 mm), esbranquiçados, com forma oval e encontrados na cavidade abdominal. Estão localizados na extremidade cranial dos rins e apresentam assimetria quanto a sua posição. Estatisticamente não há variação intra-individual no comprimento e no peso dos testículos, bem como na área e diâmetro dos lóculos seminíferos. Quanto à histologia testicular, foi possível identificar ao longo do ano nos lóculos seminíferos, todos os tipos celulares da linhagem espermatogênica, caracterizando uma gametogênese contínua, corroborada por fatores ecológicos e comportamentais. Informações sobre a morfometria testicular e ciclo reprodutivo tem importante valor biológico para anuros de regiões neotropicais.

Histological aspects and structural characteristics of the testes of Dendropsophus minutus (Anura, Hylidae)

“…Testes of D. minutus are located in the abdominal cavity, in syntopy with the visceral side of kidneys, which are in a position immediately ventral to the dorsal wall of the abdominal cavity (Santos and Oliveira, 2007). Similar general morphological characterizations of testes have been reported for Caudiverbera caudiverbera (Hermosilla et al, 1983), Scinax fuscovarius (Oliveira and Vicentini, 1998), and Eupemphix nattereri (Oliveira and Zieri, 2005).…”

“…In anuran amphibians, testes are paired, round, compact, and usually yellowish (Goin and Goin, 1962). They are surrounded by a thin and fibrous connective tissue capsule, the tunica albuginea, which presents seminiferous structures, namely the seminiferous tubule (Oliveira et al, 2002;Santos and Oliveira, 2007). In general, different cellular types are found in the germ tissue of the seminiferous tubule: spermatogonia at the base of the germ epithelium; spermatocytes and spermatids in the cellular differentiation sequence; and spermatozoids in the lumen (Oliveira et al, 2003).…”

“…Morphofunctional characteristics of Dendropsophus minutus reproduction (Peters, 1872) were presented by Santos and Oliveira (2007) who described the annual reproductive cycle based on gonadal anatomical characteristics. In the present study we propose to analyze the testicular morphological arrangement, describing the histological aspects and structural characteristics of germ cells and their cystic arrangement in D. minutus.…”

The Reproductive Biology of the InvasiveLithobates catesbeianus(Amphibia: Anura)

“…The synchrony found in the reproductive period of this species also applies to L. catesbeianus populations introduced in southern Brazil (Kaefer et al, 2007) and to populations of native southern species (Melchiors et al, 2004;Conte and Machado, 2005;Toledo and Haddad, 2005;Santos and Oliveira, 2007).…”

Structural properties of beds packed with agro-industrial solid by-products applicable for solid-state fermentation: Experimental data and effects on process performance

“…Since the moisture content affects the cellular structure of SCB fibers, the fibers cell-size were analyzed microscopically according to Santos and Oliveira [16]. For each selected MC, twenty fibers lengths varying between 1 and 1.5 cm were selected and submitted to histological staining by Periodic Acid Schiff (PAS).…”