Análise da diversidade e estrutura genética de Fenneropenaeus indicus e Metapenaeus monoceros com base no mtDNA e uso do DNA barcoding na identificação das espécies de Peneídeos (Crustacea, Decapoda, Penaeidae) da costa de Moçambique

Abstract

The penaeid shrimp (Crustacea, Decapoda, Penaeidae) are the most economically fishing resource of the greatest global importance both for fisheries and the aquaculture industry. Shrimp fishing is one of the pillars of national economy in Mozambique, where they provide around USD 80,000,000 per year in export earnings. In recent years there has been observing a reduction in the shrimp fishery industry probably due the over-exploitation or due the presence of other shrimp species that were not been observed on the coast Mozambique before which may competing for the ecological niche. Despite the great fishing economic importance of penaeid shrimps in Mozambique, there is no genetic scientific literature available thus far on their genetic characteristics. Therefore, this is the first work addressing the genetic diversity of penaeids species of greatest economic value from Mozambique coast F. indicus and M. monoceros, for the first time shrimp from this coast were identified using DNA Barcoding tool. In addition, for the first time sequences of penaeid shrimp from Mozambique coast were deposited in GenBank and Bold system. The objective of this study was to evaluate the genetic diversity and population structure of the species F. indicus and M. monoceros, and identify nine species of penaeids from the Mozambican coast. To assess the genetic diversity and structure of F. indicus and M. monoceros, 160 samples were collected along the Mozambique coast. Three mitochondrial genes (COI, Cyt b, and the control region D-loop) were analyzed. A great genetic diversity was observed, however, the D-loop presented higher values (F. indicus: Hd = 1, h = 13; Hi = 0.0133, M. monoceros Hd = 0,99; H-24; and Hi = 0.0092). D-loop showed unique haplotypes; the Tajima D test and Fu Fs values were negative and significant for the COI and Cyt b genes. The mismatch distribution curves suggested that the two espéceis undergone to a recent population expansion (10.397 to 28.418) years ago F. indicus and M. monoceros respectively. The AMOVA analysis showed that over 99% of the variation occurs within populations. The Fst Pairwise values pointed to a non structured population. The nature of ocean currents along the Mozambique channel as well as the complete absence of physical and / or environmental barriers may be the main factors that influence the non structure of these two species. To identify shrimp penaeids from Mozambique based on DNA barcondig, a total of 69 samples were collected in the Maputo Bay. The genetic distance tree grouped six species into two clades as to the place of origin, suggesting the presence of cryptic species. The intraspecific genetic distance ranged from (0 to 8.636) and interspecific distance from (3.897 to 21.558). The distance distribution analysis 10 of the nearest neighbor ranged from (3.897-18.971). The DNA Barcoding identification tool was efficient to identify the Penaeid species from mozambican coast. However the presence of cryptic species pointed the need for further studies which must be conducted using molecular analyzes; morphological taxonomy and the ecological treats to evaluate each of the sibling species to reach a correct decision of the taxonomic status.