Aspectos da espermatogênese de tucunaré, Cichla ocellaris Schneider, 1801 (TELEOSTEI, CICHLIDAE).

Abstract

SDMMARY Szqaznti INTRODUÇÃOUm número razoável de estudos sobre a espermatogênese de teíeõsteos,tem aparecido nos últimos anos (Stanley, 1969; Mattei e Mattei, 1973 e 1978Grier, 1973;C1erot,1979; Bruslè, I98l; Biílard, 1983). A maioria deles, no entanto, tem escopo limitado a deter minados aspectos, seja do espermatozoide, seja da espermiogenese e refere-se a uma uni ca espécie. Assim sendo, antes que se possa ter uma visão geral do processo espermatogênico nos peixes teleósteos, muitos outros trabalhos serio necessários.No caso particular dos peixes brasileiros, praticamente nada tem sido feito sobre a produção das células gaméticas em si, mormente a nível ultraestrutural,razão pela qual nos decidimos a apresentar a presente contribuição. MATERIAL E MÉTODOSEspecimens de Cíchia ocellaris foram coletados no Rio Negro durante o mês de ju lho. Fragmentos de testículos com aproximadamente 1 mm de lado foram fixados a 4°C em glutaraldeído a 2,5¾ em tampão cacodilato de sódio 0,IK a pH 7>4; por duas horas. Apôs lavagem no tampão os fragmentos foram post-fixados em tetróxido de ósmio a 1¾ no mesmo tampão, durante I hora. 0 tecido foi então desidratado em série crescente de álcool etf

Ultrastructural analysis of spermiogenesis in the neotropical cichlidCichla kelberiKullander & Ferreira, 2006 (Perciformes: Cichlidae)

“…The most of teleost spermatozoon is composed by head, midpiece and flagellum (Jamieson, ). The C. kelberi spermatozoon head format is similar to the other cichlids species (Mattei, ; Cruz‐Landim and Cruz‐Hofling, ; Jamieson, ; Silva and Godinho, ; Matos et al., ; Fishelson, ; Quagio‐Grassiotto et al., ; Jamieson, ), and according Jamieson () presents a nuclear chromatin condensation pattern similar, common to the family, also found in the C. ocellaris, C. intermedia and Tilapia zillii spermatozoon (Cruz‐Landim and Cruz‐Hofling, ; Fishelson, ; Quagio‐Grassiotto et al., ). Differing, however, of Satanoperca jurupari, one intern self‐fertilizing hermaphrodite specie, which present slightly elongated head (Matos et al., ).…”

“…Both types are present in the Perciform Order, however, the Type II is the most frequent, occurring in 29 from the 41 studied family, giving it the name of perciform spermatozoon (Mattei, ; Jamieson, ; Mattei, ; Abascal et al., ; Jamieson, ). However, against this tendency, the most species of the Cichlidae family, including C. kelberi in the present study, present the Type I (Mattei, ; Cruz‐Landim and Cruz‐Hofling, ; Jamieson, ; Silva and Godinho, ; Matos et al., ; Quagio‐Grassiotto et al., ; Jamieson, ; Vázquez et al., ).…”

“…In the spermatozoon of some species the midpiece can be divided in two portions: collar, in which the mitochondria are localized, and: cytoplasmic sheath that extend from the collar and not end mitochondria (Jamieson, ). The cytoplasmic sheath can be present or absent in the same family (Jamieson, ), like in the Cichlidae family, in which the Hemicrhomis fasciatus specie, does not show this characteristic, differing from species of the Cichla genus and Oreochomis niloticus (Mattei, ; Silva and Godinho, ; Cruz‐Landim and Cruz‐Hofling, ; Quagio‐Grassiotto et al., ). Similar observations also were found in Characiformes (Jamieson, ).…”

“…Going on with Perciform, some of its representative can form one, two or even three lateral expansions from the flagellar membrane called ‘fins’ (Jamieson, ; Mattei, ). In the cichlids, as in C. kelberi, the fins are present in a pair, with lengths which vary according the specie (Cruz‐Landim and Cruz‐Hofling, ; Jamieson, ; Silva and Godinho, ; Matos et al., , ; Quagio‐Grassiotto et al., ; Vázquez et al., ). Nevertheless, it isn't one common family characteristic, because according Jamieson (), this structure was not observed in 13 species of Cichlidae, including some studied by Fishelson ().…”

“…The number of works on the ultrastructure of spermatogenesis in teleosts has significantly increased in recent years (Billard, ; Mattei, ; Bruslé, ; Mattei, ; Veríssimo‐Silveira et al., ; Spadella et al., ; Magalhães et al., ; Viveiros et al., ). However, considering the high diversity of freshwater Neotropical cichlids, the descriptions of the ultrastructure of spermiogenesis and spermatozoa in the Genus Cichla is unsatisfactory, so far focussing only on the C. ocellaris and C. intemedia species (Cruz‐Landim and Cruz‐Hofling, ; Quagio‐Grassiotto et al., ).…”