Embryonic and larval development of Jundiá (Rhamdia quelen, Quoy & Gaimard, 1824, Pisces, Teleostei), a South American Catfish

Estudo do desenvolvimento embrionário e larval do jundiá, Rhamdia quelen, (Quoy & Gaimard 1824, Pisces Teleostei)

The jundiá (Rhamdia quelen, Quoy & Gaimard) is an endemic South American fish species. Because this species supports cold winters and grows faster during warm months, it has begun to be viewed as an ideal species for fish production in southern South America. In the present study, jundiá oocytes used were obtained by extrusion from females after hormone injection. Soon after hydration, the eggs were transferred to 50 L conic glass incubators, with constant and controlled water influx. Samples of fertilized eggs were transferred to Petri dishes and, examined under a stereoscopic microscope, were spherical, demersal, and non-adhesive with defined perivitelline space and resistant chorion. Cleavage stages occurred during the first 3.5 h. After hatching, larvae were transferred to 200 L glass fiber incubators. First signs of embryo movement were observed 21 h after fertilization; larval eclosion occurred 30.5 h after fertilization. Present findings may provide a basis for studies aimed at determining the complete ontogeny of jundiá and may be useful in eco-toxicological studies.

embryonic development; larval development; embryology; Rhamdia; jundiá

Instituto Internacional de Ecologia R. Bento Carlos, 750, 13560-660 São Carlos SP - Brasil, Tel. e Fax: (55 16) 3362-5400 - São Carlos - SP - Brazil
E-mail: bjb@bjb.com.br