Resumen

NAVARRO, Rodrigo Diana et al. Dietary digestible energy levels on the gonad development of Piauçu (Leporinus macrocephalus) in post larvae stage. Zootecnia Trop. [online]. 2006, vol.24, n.2, pp.153-163. ISSN 0798-7269.

The objective of this study was to evaluate the effect of energy levels on testicular development of the piauçu (Leporinus macrocephalus). Six hundred fishes, averaging initial weight and length of 0.33 ± 0.11 g and 2.94 ± 0.39, respectively, were utilized. The experiment was carried out according to a completely randomized design, with 4 treatments (2600, 2700, 2800, and 2900 kcal DE/kg). Energy level did not significantly affect average final body weight and total length. Quadratic effect on gonads weight (P<0.02) at 60 days was verified. Quadratic effect on the gonad-somatic index (P<0.02) at 60 days was verified. The treatments with 2800 and 2900 kcal DE/kg showed the primary and secondary spermatogonia rounded by Sertoli cells in a typical cyst formation. The treatments with 2600 and 2700 kcal DE/kg showed development of primary spermatogonia cyst only.

Palabras clave : gonadal development; gonad-somatic index; energy; piauçu.