Relações genéticas em espécies de camarões peneídeos (Crustacea, Decapoda, Penaeidae) de ocorrência no litoral brasileiro
Resumo
Penaeidae family occurs in all oceans, particularly in tropical regions and represents an important
global fishing resource. In Brazil, penaeid species have been shown decline, of their populations,
which are considered overexploited. Therefore, a greater knowledge about these species is required
for the developing of appropriate conservation actions. However, genetic studies of penaeids,
including phylogeography, geographic distribution and phylogeny, are still scarce. In the present work,
genetic structure and genetic relationships were characterized for different marine shrimp species
belonging to the Penaeidae family, with special emphasis on those of occurrence in the Brazilian coast
(Xiphopenaeus kroyeri, Farfantepenaeus paulensis, Farfantepenaeus subtilis and Farfantepenaeus
brasiliensis). Mitochondrial and nuclear markers were used in order to clarify aspects related to the
geographic distribution and genetic relationships among the studied penaeid species and the
implications for conservationist approaches. Specific oligonucleotides were designed to amplify four
mtDNA regions (COI, 16S, Cytb and DLoop). The results showed efficient patterns for 16 native
species of Brazilian and Mozambican coasts. Numts presence and its implication for penaeid genetics
were investigated using specific and universal primers for COI gene. Pseudogenes were detected for
some penaeid species. Cytb pseudogene for the Penaeidae family was reported by the first time. DNA
barcoding approach was tested in several species from Brazilian coast. The barcoding analysis
evidenced a high range of intraspecific distance, suggesting the necessity of taxonomic review into
Penaeidae. The existence of species complex was investigated for both X. kroyeri and F. subtilis.
Phylogeographical signs and population structure were no observed for F. subtilis along the Brazilian
coast. F. paulensis populations, collected in Lagoa dos Patos (RS) and Cananéia (SP), showed
genetic structuring by analyzing of COI gene. That data can be reflecting the existence of
differentiated-genetically adult stocks or ancient structure. Two recent population expansions, one of
them before and the other one after the last period of the maximum glacial, were observed for F.
paulensis. mtDNA and RAD-seq data were using to study the species X. kroyeri populations. The
mtDNA analysis suggested that the upwelling from Cabo Frio (RJ) consists in a semipermeable barrier
to X. kroyeri species, limiting the genetic flow between populations from North and South of Cabo Frio
for. The analysis of approximately three thousand SNPs revealed three different genetic stocks,
possibly related to the hydrodynamic characteristics of the sampled geographic regions, which may be
holding different larvae pools. The study herein brings important information about genetic
relationships and population structure for Penaeidae species, mainly those species occurring in Brazil.
Such data can be help to foment future actions aiming the conservation of penaeid species, which
present ecological and socioeconomic relevance.