Presencia de Hippocampus patagonicus (Syngnathiformes: Syngnathidae) en el estuario externo del Río Negro, provincia de Río Negro, Argentina

Abstract

The order Syngnathiformes includes pipefishes and seahorses, with Hi ppocampus being the only genus comprising the latter. They exhibit a global distribution across tropical and temperate regions. Seahorses face multiple anthropogenic threats, which have led many species to be classified as Vulnerable by the IUCN. This study reports the presence of Hippocampus patagonicus in the outer estuary of the Negro River, Argentina. A stranded female specimen of H. patagonicus was documented on the coast of the outer Negro River estuary. As the specimen was incomplete, only the following morphometric measurements were recorded: trunk length, dorsal fin base length, pectoral fin base length, head length, snout length, postorbital distance, and orbital distance. The meristic characters used included: number of trunk rings, number of anal fin rays, number of pectoral fin rays, and number of dorsal fin rays. Based on the morphometric values obtained, the specimen was identified as a small-sized female. This record is significant given the species’ vulnerable status and the fact that the population in San An tonio Bay has declined by approximately 90% over the past 30 years. Furthermore, it is essential to intensify research efforts in the area to determine whether this finding represents an isolated occurrence or evidence of an established population within the study site.