Pesquisa de agentes de notificação obrigatória em moluscos bivalves de ambiente natural na ilha do Maranhão, Brasil

Abstract

Bivalve molluscs are present throughout the coast of Maranhão and represent, in addition to food, a source of income. Due to their filtering physiology, they act as bioindicators of the environment in which they are inserted, as well as being affected by protozoa such as Bonamia spp. and Perkinsus spp. that are agents responsible for diseases that generate population reduction and economic impact. In this context, the objective was to investigate compulsory notification agents in bivalve molluscs from the natural environment on the Island of Maranhão, Brazil. For this, 90 specimens of Mytella spp. (mussel), 90 specimens of Anomalocardia spp. (clam) and 63 specimens of Crassostrea spp. (oysters). After collection, the specimens were stored in thermal boxes and transported to the laboratory to be processed on the same day. They were cleaned with sea water and separated by similar sizes. The animals' valves were opened with the aid of scalpels and the gill tissue was removed. The animals were separated into pools, where each pool contained 3 animals, thus totaling 30 pools of Mytella spp. mussel), 30 pools of Anomalocardia spp. (clam) and 21 pools of Crassostrea spp. (oysters) for DNA extraction. They were then submitted to the Polymerase Chain Reaction (PCR) technique using three specific genes, 18SrDNA, SSURDNA and ITSrRNA. Molecular analyzes were performed and it was not possible to detect the presence of the protozoa Bonamia spp. and Perkinsus spp. in bivalve molluscs in the samples evaluated in Maranhão Island. Although there are no reports of positive samples and no mortality has been noted, the present study provides important information about the lack of circulation of compulsory notifiable agents, Bonamia spp. and Perkinsus spp. in the studied area and points to the need for active surveillance and the implementation of public policies aimed at the health of aquatic animals