Stranding of Masturus lanceolatus (Actinopterygii: Molidae) in the estuary of the Una River, Pernambuco, Brazil: natural and anthropogenic causes.

Molidae are tropical marine teleosts that occur in all oceans. Among the species described, Masturus lanceolatus is considered rare on the Brazilian coast, with only four records found in scientific publications. The present study reports the first occurrence of this species for the coast of the State of Pernambuco (north-eastern Brazil) and discusses the possible causes of its being stranded. The specimen was found alive in the estuary of the Una River in the city of São José da Coroa Grande on the southern coast of the state. The fish was unknown to the local community of fishermen, who considered it a 'bad omen'. The occurrence led to an environmental education project in the community carried out by members of the Tropical Marine Ichthyology Group, which carried out an inspection, documentation, analysis of external injuries and collection of viscera for the subsequent histological analysis. After undergoing taxidermy, the specimen was donated to the Una Museum. Analysis revealed that the fish suffered from an intense inflammatory process of the liver caused by polycystosis of nematodes and Trypanorhyncha, which resulted in malnutrition, as observed by the low body weight. Moreover, a likely stranding left the specimen more vulnerable to different species of shark, which mutilated it, hindering its locomotion. This fish appears to have drifted and was thrown against the reefs near the estuary before its stranding. [ABSTRACT FROM AUTHOR]