Identification of Two Common Bottlenose Dolphin () Ecotypes in the Guadeloupe Archipelago, Eastern Caribbean.

The common bottlenose dolphin () exhibits significant intraspecific diversity globally, with distinct ecotypes identified in various regions. In the Guadeloupe archipelago, the citizen science NGO OMMAG has been monitoring these dolphins for over a decade, documenting two distinct morphotypes. This study investigates whether these morphotypes represent coastal and oceanic ecotypes, which have not been previously identified in the region. We characterized morphological differences between the two morphotypes, analyzed genetic variation in individuals stranded around Guadeloupe over the past ten years, and modeled their habitats. Results revealed that these morphotypes align with the ecotypes described in the Atlantic Ocean, forming two distinct genetic groups corresponding to Caribbean ecotypes. Habitat modeling showed differences in habitat preferences between the morphotypes. These findings provide strong evidence for the existence of two distinct ecotypes of in Guadeloupe. Considering the varied risks of exposure to maritime traffic, our study suggests that these ecotypes should be managed as separate units within the species to better inform conservation strategies in the region.