Qualitative parameters of the piapara semen (Leporinus elongatus Valenciennes, 1850) / Parâmetros qualitativos do sêmen de piapara (Leporinus elongatus Valenciennes, 1850)

Qualitative parameters of piapara semen (Leporinus elongatus) were evaluated before and after hormonal induction with carp pituitary extract at 2.5 mg.kg-1 of live weight. The progressive motility, the spermatic vigor and the lifetime of the spermatozoa were higher before the hormonal induction (P > 0.05). The percentage of normal spermatozoa and spermatozoa with secondary pathologies did not differ (P > 0.05) between treatments: before induction (44.0 and 44.4 percent, respectively) and after-induction (44.3 and 46.7 percent, respectively). However, the percentage of primary pathologies was higher (P < 0.05) for the semen collected before induction than for the semen collected after induction; the estimates were 12.2 and 8.0 percent, respectively. The most frequent pathologies were the taillessness with the frequencies of 27.4 and 36.3 percent followed by the headlessness for which the estimates were 10.1 and 3.9 percent, before and after induction respectively. The semen collected before the hormonal induction presented better qualitative parameters.

Os parâmetros qualitativos do sêmen de piaparas (Leporinus elongatus) foram avaliados antes e após a indução hormonal com o extrato de hipófise de carpa na dosagem 2,5 mg.kg-1 de peso vivo. A motilidade progressiva, o vigor espermático e o tempo de vida dos espermatozóides apresentaram valores superiores (P < 0,05) no sêmen coletado antes da indução hormonal. Já a estimativa da porcentagem de espermatozóides normais ou com patologias leves, na pré-indução (44,0 e 44,4 por cento, respectivamente) e na pós-indução hormonal (44,3 e 46,7 por cento, respectivamente) não diferiram (P > 0,05) entre os tratamentos. Porém a estimativa de patologias graves foi maior (P < 0,05) no sêmen de pré-indução do que no pós-induzido com 12,2 e 8 por cento, respectivamente. A patologia mais freqüente foi cabeça solta com 27,4 e 36,3 por cento seguida por cauda solta com 10,1 e 3,9 por cento, antes e após a indução hormonal respectivamente. De acordo com os resultados, o sêmen de piapara coletado na pré-indução hormonal apresentou os melhores parâmetros qualitativos.

In vitro effect of mammalian pituitary hormones on germinal vesicle breakdown in oocytes of major carps, Labeo rohita, Cirrhinus mrigala, Catla catla and Cyprinus carpio.

Among all the mammalian pituitary hormones, luteinizing hormone (LH) was the most potent in vitro inducer of oocyte maturation in L. rohita, C. mrigala, C. catla and C. carpio. It induced significant germinal vesicle breakdown (GVBD) at concentrations of 10, 1, 0.1 and 0.01 micrograms/ml. At the highest concentration used, LH induced 77.9 +/- 5.9, 73.8 +/- 4.6, 50.3 +/- 2.8 and 40.8 +/- 1.4% GVBD in oocytes of L. rohita, C. mrigala, C. catla and C. carpio, respectively. Among other hormones, follicle stimulating hormone (FSH) induced only a marginally significant GVBD (13.2 +/- 0.8%) in the oocytes of C. carpio, but not in other three species. Thyroid stimulating hormone (TSH), growth hormone (GH) and prolactin (PRL) had no effect on GVBD.