Análise morfométrica do camarão de água doce Macrobrachium rosenbergii e do camarão marinho Litopenaeus vannamei

Abstract

Since the 1980s, shrimp farming has been marked by great worldwide growth, due to the reduction of fish stocks and an increase in demand for food. In Brazil, shrimp farming is based on two main species: On sea prawn, Litopenaeus vannamei, and freshwater prawn, Macrobrachium rosenbergii. Between these two species, marine shrimp predominates absolutely in relation to freshwater shrimp, but with the appearance of some diseases this growth has cooled. In this scenario, freshwater shrimp farming finds room for expansion of its production, and it is important to highlight information on the biology of the animal for the best knowledge of the species. Analyzing the growth of the animal helps to interpret many aspects of the life strategy of a species, such as studying the energy used for its growth and maintenance. M. rosenbergii has been studied in order to obtain knowledge about biology and its ontogenetic development. Research has become important in order to contribute to the increase of the production of this species. Therefore, to promote morphometric evaluations is important because we thus draw a parallel between the species that stand out most in shrimp farming. For this, the M. rosenbergii prawns were stored in a nursery with an area of 1000 m2, being 10 shrimps / m2. The morphometric data of M rosenbergii were collected from animals between 5-50g, while for L. vannamei between 5-15g, weights commonly obtained in the commercial fattening of these species. The animals were sacrificed and the following morphometric measurements were obtained: Total weight, total length, abdomen weight and hepatopancreas weight. The results showed that, the average percentage of abdomen shows a clear tendency of decrease with its growth. The highest percentage of abdomen was 44.52% in class 1. We also found that the highest HI was found in shrimps weighing 45g, with 7.26% of the total weight of shrimps. The results indicate that some somatic indices differ according to the development of shrimps, especially the index related to the abdomen, which, as its ontogenetic development occurs, this percentage decreases. Thus, characterizing a greater energy investment for the reproduction, instead of growth, in animals of heavier weight.