Preliminary aspects of the reproductive handling in captivity of doncella (Ageneiosus pardalis Lütken, 1874)

Objective. To evaluate handling procedures in captivity of mature specimens, with reproduction purposes, of doncella Ageneiosus pardalis, and to present the first advance in the description of embryonic and larval development for the species. Materials and methods. Several reproduction tests were carried out in specimens maintained in captivity, as follows: a) Spermiation and ovulation were induced with Carp pituitary extract CPE (4 mg/kg; an intraperitoneal dose for spermiation) and (0.5 and 5 mg/kg; intraperitoneal for ovulation, 0 and 12 hours); b) only females maintained in tanks, without males present, were induced. Eggs obtained from tanks were recollected and observed. Results. Ovulation and spermiation were verified, but embryonic development was not advanced when gametes were mixed and incubated. Testing with induced females, without males present, confirms sperm storage in ovaries, and eggs show a complete embryonic development, achieving hatching of larvae and maintenance of young fish. Conclusions. The conventional protocol using induction was effective in females and males, but the mixed products did not prove to be a viable procedure for seed production in the species. Sperm storage in females and spontaneous emission of fertilized eggs in their habitat, when they were subjected to induction, was confirmed. Form and sperm as well as physiological mechanisms occurring in fertilization are unknown.