Gonadal structure and gametogenesis of Loricaria lentiginosa Isbrücker (Pisces, Teleostei, Siluriformes)

Abstract

ABSTRACT. The gonadal structure and gametogenesis of Loricaria lentiginosa Isbrücker, 1979 were studied through anatomical and histological techniques. Forty two males and ten females in maturation/mature stage were captured in the reservoir of Porto Colombia, Paraná river basin, Minas Gerais, using gill nets, from November 2001 to October 2002 (tri-monthly captures). Examination of the testes revealed that they were paired, elongated and not fringed organs. Histologically, the testes presented three distinct regions: cranial espermatogenic; transistion espermatogenic and secretory; and caudal exclusively secretory. Standard histochemical techniques detected neutral glycoproteins from the secretion of the tubules of the caudal region. Espermatogenesis occurred in cysts throughout the whole extension of the wall of the seminiferous tubules, which anastomosis themselves and liberated the spermatozoa into the lumen of the espermatic ducts. The ovaries were paired, saculiformes and, histologically, they presented ovigerous lamellae that contained the cells of ovogenic ancestry. The oocytes were classified into four stages, based on their cytological characteristics and the cell layers that surrounded them. Post-ovulatory follicles and vitelogenic oocytes in the follicular atresia process also were observed.

Reproductive biology of the endangered percid <i>Zingel asper</i> in captivity: a histological description of the male reproductive cycle

“…The SPGA and SPGB observed are morphologically similar to teleost spermatogonia widely described in the literature by means of light microscopy [65][66][67] and electron microscopy [22,53,68].…”

Reproductive apparatus and gametogenesis of Lophiosilurus alexandri Steindachner (Pisces, Teleostei, Siluriformes)

“…In L. alexandri the oogonia were the smallest of the oogenic lineage cells and displayed a morphology similar to the one found in other teleost species studied (GRIER 2000, GUIMARÃES-CRUZ et al 2005. During the primary oocyte growth in L. alexandri the formation of a yolk nucleus and a cortical alveolus was observed.…”

“…The morphology of the ovaries of L. alexandri is similar to the morphology of the ovaries of other Siluriformes as P. coruscans (BRITO & BAZZOLI 2003), P. fasciatum (ROMAGOSA et al 2003), I. labrosus and L. lentiginosa (GUIMARÃES-CRUZ et al 2005). Following HOAR (1969) classification the ovaries of L. alexandri are cystovarian, since they present a complete ovarian capsule and an ovarian duct.…”

“…Espermatogênese, gônadas, morfologia, ovogênese, Pseudopimelodidae. not fringed and, at their caudal region, present a diffuse secretory tissue that does not form a conspicuous gland (GUIMARÃES-CRUZ et al 2005).…”

“…The female reproductive system of some Siluriformes species that have been studied is characterized by having paired, elongated ovaries which communicate through the oviduct with the urogenital papillae and are located dorsally in the coelomic cavity (ROMAGOSA et al 2003, GUIMARÃES-CRUZ et al 2005. The ovaries are surrounded by a capsule made of dense conjunctive tissue that constitutes the tunica albuginea and emits projections to the interior of the organ where it forms the ovigerous lamellae.…”