Estudo da dinâmica e abundância populacional de Camarões penaeideos no estuário dos Bons Sinais, distrito de Quelimane

Abstract

The present study identifies the specific composition of the shrimp that occurs in the estuary, characterizes the structure of the population and relates the influence of environmental factors (tide, salinity and temperature) on the abundance of prawns of the family Penaeidae in the Bons Sinais estuary. The sampling frequency was monthly for a period of one year from September 2017 to August 2018. The collections were carried out at two points at the Icidua and the Chuabo dembe fishing center at live tide. In relation to the objective of relating the influence of environmental factors (tide, salinity and temperature) on the abundance of prawns of the penaeidae family, fishing was carried out using a passive net (Chicocota) at the Chuabo dembe fishing center during five consecutive tide for a period of three months from April to June 2018.There were 8488 individuals, corresponding to four families (Penaeidae, Palaemonidae, Alpheidae and Sergestidae). Four species of the family Penaeidae were captured: Fenneropenaeus indicus, Metapenaeus monoceros, Parapenaeopsis sculptilis and Penaeus monodon, of which two species Fenneropenaeus indicus and Metapenaeus monoceros constituted about 98% in the capture of the individuals of this family.For F. indicus species, a carapace length distribution of 5 to 56 mm was observed and for M. monoceros the lengths varied from 8 to 38 mm, the species Parapenaeopsis sculptilis with 0.4 to 60 mm. Females were dominant in both species. In relation to the abundance of the species were compared in number of individuals of the three species using the t-student test in each phase of the tide (flood and ebb). However, there was no significant difference in the abundance of individuals of the species in relation the tide, F. indicus (t = 0.21 and p = 0.84), M. monoceros (t = -1.2 and p = 0.27) and P. sculptilis (t = -0.25 and p = 0.81). The temperature and salinity showed a positive correlation with abundance of the species, but did not influence its abundance. However, the results indicate that the Bons Sinais estuary is an important habitat for species of this economically important family of shrimp in the country, and a sustainable exploitation should be done.