A influência da ablação unilateral do pedúnculo ocular e a reprodução do camarão de água doce Macrobrachium acanthurus (Wiegmann, 1836) em cativeiro

Abstract

Macrobrachium acanthurus is the freshwater prawn species that is find in almost whole coastal rivers in Brazilian coast. This work was carried out to get information about reproductive aspects of Macrobrachium acanthurus in captivity and the influence on unilateral eyestalk ablation technique. 48 females and 24 males were captured in Sahy river at Mangaratiba/RJ and kept in adaptation for 15 days. Then, the animals carapace length and total length were measured. They were distributed into 20 liters aquariums, each of them with two males and four females. Two females in each aquarium were ablated. Abiotic factors such as pH, ammonia, nitrite and oxygen levels were checked weekly and the water temperature daily. Every day the occurrence of ovigerous females were checked in each aquarium. After three days incubating, the ovigerous females were separated until the larvae eclosion. And then, they were returned to the aquarium for a new phase of reproduction. The animals were fed with ration pellets and pieces of fish. The U test (Mann-Whitney) showed a significant difference among laying intervals between the ablated and non-ablated females. The Pearson correlation showed temperature influence on incubation period on non-ablated females, but on ablated females there was no dependency relationship. The t-test showed no significant difference on fertility, between ablated and non-ablated M. acanthurus.