Características ultra-estruturais e diferenciativas das espermátides de piracanjuba (Brycon orbignyanus) durante a espermiogênese

Spermiogenesis and spermatozoa ultrastructure in the Serrasalminae (Ostariophysi: Characiformes) with further evidence on the relationships of the piranhas and pacus

“…They are differentiated by the floccus of chromatin smallest and thinnest, by the midpiece and cytoplasmic sleeve shape and length of the last genus. Those of the genus Piaractus (Cruz-Landim et al, 2003; current paper) are quite distinct, and have a great similarity with the spermatozoa of the genera Salminus and Brycon (Aires et al, 2000;Romagosa et al, 1999;Zaiden, 2000;Veríssimo-Silveira et al, 2006). The type of chromatin condensation in floccus, the ovoid shape of the nucleus, the length of the midpiece, the mitochondria shape and distribution, and the presence of a well defined cytoplasmic sleeve response by this similarity.…”

“…In this case, the flagellum is eccentric to the nuclear axis, and the spermatozoa are of an intermediate type between types I and II (Mattei, 1970). Among the external fertilizing Characiformes, spermatozoa of the type I is the dominant type (Jamieson, 1991;Matos et al, 1993Matos et al, , 1998Burns et al, 1998;Magalhães, 1998;Romagosa et al, 1999;Aires et al, 2000;Zaiden, 2000;Andrade et al, 2001;Quagio-Grassiotto et al, 2001aAmaral, 2003;Cruz-Landim et al, 2003;Pecio, 2003;Azevedo, 2004;Weitzman et al, 2005;Veríssimo-Silveira et al, 2006;Oliveira, 2007;Pecio et al, 2007;Veríssimo-Silveira, 2007).…”

“…In the serrasalmine spermatozoa (Matos et al, 1993;Cruz-Landim et al, 2003; current paper) the nucleus is occupied by large floccus of fibrous chromatin. Among the Characiformes this kind of chromatin condensation has been described for Citharinus sp., Citharinidae (Mattei et al, 1995), in Leporinus friderici, Leporinus macrocephalus, Leporinus lacustris, and Abramites sp., Anostomidae (Matos et al, 1999;Amaral, 2003;Veríssimo-Silveira, 2007, respectively), in Prochilodus lineatus, Prochilodontidae (Vicentini et al, 2001;Veríssimo-Silveira, 2007), in Rhaphiodon vulpinus Cynodontidae (Veríssimo-Silveira, 2007), in the characid genera Salminus (Veríssimo-Silveira et al, 2006) and Brycon (Aires et al, 2000;Romagosa et al, 1999;Zaiden, 2000;Veríssimo-Silveira et al, 2006), and in Alestes dentex, a relatively basal genus within the Alestidae (Shahin, 2006). Interestingly, in Micralestes sp.…”

“…Spermiogenesis and spermatozoa types, organell distribution and other particularities of the spermatic structure, have been found to be highly conservative in a given lineage at family or subfamily level, making them useful for phylogenetic analysis (Baccetti et al, 1984;Jamieson, 1991;Mattei, 1991;Burns et al, 1998;Quagio-Grassiotto et al, 2003). Regarding the Characiformes, and particularly the Characidae, the available information is still scarce considering the large diversity of the group (Jamieson, 1991;Matos et al, 1993Matos et al, , 1998Matos et al, , 2000Burns et al, 1998;Magalhães, 1998;Pecio & Rafinski, 1999;Romagosa et al, 1999;Aires et al, 2000;Zaiden, 2000;Andrade et al, 2001;Quagio-Grassiotto et al, 2001aAmaral, 2003;Cruz-Landim et al, 2003;Pecio, 2003;Azevedo, 2004;Pecio et al, 2005Pecio et al, , 2007Weitzman et al, 2005;Veríssimo-Silveira et al, 2006).…”