The sperm of Hylodinae species (Anura, Leptodactylidae): ultrastructural characteristics and their relevance to interspecific taxonomic relationships.

Hylodinae leptodactylids (sensu Lynch 1971) form a group of diurnal frogs, which is hypothesized on the basis of morphological traits to be the closest relatives of the dendrobatid frogs. Our study describes ultrastructural characteristics of sperm from three hylodine species (Hylodes phyllodes, Crossodactylus sp. n. and Megaelosia massarti) to reassess the intergeneric relationships within the Hylodinae, as well as the supposed relationship between the Hylodinae and Dendrobatidae. The ultrastructure of the sperm is very similar among the three species and is indicative of its conserved nature within the Hylodinae. The structure of the acrosomal complex was very similar to that of other leptodactylid species, to most of the remaining species included in the Bufonoidea lineage, and also to that observed in the dendrobatid species examined so far. Since such a structure has been considered a plesiomorphic trait, it contributes little to our understanding of the relationships between the Hylodinae and Dendrobatidae. The flagellar apparatus of Crossodactylus sp. n. is very similar to that of most leptodactylids. The sperm of Megaelosia massarti and Hylodes phyllodes display a distinctive condition in their axial and juxtaxonemal fibers. This distinctive flagellar condition expands the already known variability in sperm structure within the Leptodactylidae.

An ultrastructural study of spermiogenesis in three species of Physalaemus (Anura, Leptodactylidae)

Ultrastructural aspects of spermiogenesis and testicular spermatozoa of three anuran amphibians, Physalaemus biligonigerus, P. fuscomaculatus and P. gracilis, were investigated by electron microscopy. The nuclei, middle pieces and tails of the three species were similar. In all cases, the nuclei were elongated and the acrosome consisted of a cone-shaped cap. The connecting pieces located in the flagellum implantation zone had transverse striations. The tails had a 9 + 2 axial filament pattern, a juxtaxonemal fiber and an undulating membrane. In contrast to other Leptodactylidae spermatozoa, no axial rod were observed in these Physalaemus species

Toluidine blue binding affinity and Feulgen - DNA absorption spectrum of euchromatin and B- heterochromatin of Drosophila nebulosa

O ciclo reprodutivo de femeas de Astyanax bimaculatus e caracterizado com base na variacao mensal dos valores medios do indice gonado-somatico e das frequencias de ocorrencia dos estadios de maturidade, definidos atraves das caracteristicas macro e microscopicas dos ovarios. Os especimes foram capturados no Rio Ivai (23o 40' Lat.Sul e 52o 07' Long WG) de outubro de 1979 a novembro de 1980. Durante o ciclo reprodutivo os ovarios apresentaram cinco estadios: imaturo, repouso, maturacao, reproducao e esgotado. A maturacao dos ovarios inicia-se em julho e a desova ocorre de novembro a fevereiro. Os dados sugerem que a desova seja do tipo parcelada. A primeira maturacao sexual das femeas ocorre quando atingem 78 mm de comprimento total