Case Report: Agonistic interaction between Amazonian manatee (Trichechus inunguis) and Tucuxi dolphins (Sotalia fluviatilis) in Brazil
Year: 2026
Type: article
Study design: Case Report
Abstract: Background Interspecific interactions play an important role in shaping ecological relationships, yet descriptions of social interspecific interactions in aquatic mammals remain scarce. Here, we describe a rare agonistic interspecific interaction between Tucuxi dolphins ( Sotalia fluviatilis ) and an Amazonian manatee calf ( Trichechus inunguis ) in Brazil, which resulted in the death of the manatee. Such records are unique and contribute to the understanding of behavioral repertoires of aquatic mammals. Case presentation On April 12th, 2004, an Amazonian manatee calf was rescued by local fishermen in Macapá, Amapá State, Brazil, after being attacked by Tucuxi dolphins. The calf was transferred to a rehabilitation center, but its condition deteriorated. On April 22nd, the animal died, and necropsy revealed external cone-shaped marks consistent with dolphin bites, internal thoraco-abdominal trauma, intestinal rupture, and pulmonary edema. Histopathological analyses indicated neurogenic shock as the cause of death. Conclusion This is the first documented case of aggression of Tucuxi dolphins towards an Amazonian manatee. The record highlights the importance of monitoring interspecific interactions in overlapping habitats and contributes to the scarce literature on cetacean-sirenian interactions.
Source: Frontiers in Ethology
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,353
OpenAlex ID: W7131106281