Caracterização genética do cavalo-marinho Hippocampus reidi de duas populações brasileiras com o uso de marcadores ISSR

Abstract

Seahorses are bony fish included in the genus Hippocampus. Three species of seahorse occur in Brazilian waters, H. erectus, H. patagonicus and H. reidi. The latter stands out for being the most abundant and with greatest spatial distribution. H. reidi has an important role as an intermediate predator in ecosystems where it is present. Furthermore, it is considered a “flagship species”, for its charismatic aspects that promote the conservation of the entire ecosystem. In addition to the particular biological characteristics of the genus (little production of juveniles and occurrence of monogamy), the exploitation of natural stock and destruction of habitats are additional obstacles to the maintenance of natural populations of these individuals. In this context, it is important to highlight that Brazilian species are considered endangered, according to the IUCN, data from appendix II of CITES and the Brazilian Ministry of the Environment. Molecular markers have proven to be an efficient tool for investigating population characteristics that are important for population resistance to environmental impacts. Therefore, the present research aims to carry out a preliminary genetic characterization of H. reidi from populations of the Pacoti River Estuary (CE) and Southern Pantano Beach (SC). Therefore, samples were collected from Ceará’s population, while Santa Catarina’s samples were provided after prior collection. DNA was extracted from samples for amplification by PCR using Inter Simple Sequence Repeats (ISSR) primers, a dominant molecular marker used for studies of genetic variability. With the PCR results, a presence-absence matrix was created for statistical analysis. 36 polymorphic loci were obtained, which allowed the creation of distance matrices and dendrogram using Neighbor-Joining method, where low variability was observed between specimens from the Pacoti River Estuary, when compared to organisms from Southern Pantano Beach and to interpopulation distance, which is even greater. It is concluded the seahorse populations analyzed present good intrapopulation genetic diversity and interpopulation variation. The preliminary results achieved can serve as a basis for more comprehensive studies on the ecology and genetics of seahorses.