Avaliação do efeito da serotonina (5-HT) e da monoablação do pedúnculo ocular na indução da maturação ovariana de Penaeus penicillatus (Alcock, 1905)

Abstract

Evaluation of the effect of serotonin (5-HT) and eyestalk monoablation on the induction of ovary maturation in Penaeus Penicillatus (Alcock, 1905)The effects of serotonin and of the monoablation of eyestalk on the induction of gonadal development of Penaeus penicillatus (red tail shrimp) were investigated. Immature females with an average weight of 20 g were selected and ramdonly distributed into four groups of 5 animals as follows: initial control group (IC), sacrificed at the 1 st day of the experiment; parallel control group (CG), injected with 0.05 ml of saline solution; monoablated group (AG), submitted to monoablation at day 0 and injected with 0.05ml of saline immediatelly after the monoablation and on the 5 th day; serotonin group (SG), injected with 0.05 ml of serotonin, dissolved in saline solution, both on day 0 on the 5 th day, in a total dose of 15 µg per gram of animal's weight (7,74 x 10 -7 mol). Animals were sacrificed on day 0 for the initial control group (IC), and on the 5 th , 10 th and 15 th days for the other groups. A fragment from the front lobe of the animal's gonad was fixed in aqueous Bouin and processed with the usual optic microscopy techniques. Analyses consisted of a morphological description of cells and measurements of the diameter of oocytes, which gave evidence to the stimulating role of serotonin and of monoablation on gonad maturation. The statistical analysis (Anova -SNK, P < 0.05) of the diameter values of oocytes showed monoablation to be more effective in inducing ovary maturation than serotonin at the concentration used (7,74 x 10 -7 mol).Key words: Penaeus sp., serotonin, 5-HT, reproduction, ovary maturation. RESUMOO efeito da serotonina e da monoablação do pedúnculo ocular na indução do desenvolvimento gonadal de Penaeus penicillatus (camarão do rabo vermelho) foi investigado. Fêmeas imaturas com peso médio de 20 g foram selecionadas e distribuídas de maneira aleatória em quatro grupos de 5 animais com uma réplica para cada grupo: grupo controle inicial (CI), sacrificado no 1 o dia do experimento; grupo controle paralelo (GC), injetado com 0,05 ml de solução salina; grupo monoablado (GA), submetido à monoablação no dia 0 e injetado com 0,05 ml de solução salina logo após a monoablação e no 5 o dia; grupo serotonina (GS), injetado com 0,05 ml de serotonina dissolvida em solução salina no dia 0 e 5 o dia, numa dose total de 15 µg por grama de peso do animal (7,74 x 10 -7 mol). Os animais do grupo controle inicial (CI) foram sacrificados no dia 0, e no 5 o , 10 o e 15 o dias para os demais grupos, respectivamente. Fragmentos dos lóbulos anteriores das gônadas dos animais foram fixados em Bouin