First record of the Clymene dolphin (Stenella clymene Gray, 1850) in Costa Rican waters

Abstract

Given the scarcity of cetacean records in Central American waters and even more in the Caribbean waters (Bolaños-Jiménez et al., 2014, 2021, 2023; Alvarado-Hofmeister, 2021; Valencia Cubillos, 2022), it is essential to document the presence of particular species in specific areas to refine the regional cetacean inventory. Here, we report on the presence of a dead, young Clymene dolphin in waters off Tortuguero Volcano, Caribbean Sea, the first record of the species for Costa Rica, more than 800 km afar from the nearest available record in the Gulf of Morrosquillo, Colombia (Mignucci et al., 2021). On 02 November 2022, a dead dolphin was found floating in Costa Rican waters approximately 45 km from Tortuguero Hill (approx. 10°48’N, 83°00’W, Fig. 1) by the crew of a sport fishing boat. According to the General Bathymetric Chart of the Oceans The genus Stenella includes five species, of which the Atlantic spotted (Stenella frontalis) and the Clymene (S. clymene) dolphins are endemic to the Atlantic Ocean (Perrin et al., 1981; Fertl et al., 2003; Moreno et al., 2005, Jefferson et al., 2015). The Clymene dolphin is described as the smallest of the genus Stenella and reaches at least 1.97 m (males) and 1.90 m (females); moreover, the neonatal length is unknown but is thought to be less than 1.2 m (Jefferson et al., 2015). This oceanic species is found only in the tropical and subtropical Atlantic Ocean, including the Caribbean Sea and the Gulf of Mexico, and prefers deep waters between 250-5,000 m (Perrin et al., 1981; do Amaral et al., 2015; Jefferson et al., 2015; Barragán-Barrera et al., 2019). Recent reports confirm the species’ presence in the Mexican Caribbean, Belize, Colombia, and Venezuela (Niño Torres et al., 2015; Ramos et al., 2016; Briceño et al., 2020; Mignucci et al., 2021) but records are unknown for other Caribbean Central American waters (i.e., Nicaragua, Costa Rica, and Panama).