First report of a sleeper shark (Somniosus sp.) in the western Caribbean, off the insular slope of a coral atoll

Abstract

A sleeper shark (Somniosus sp.) was captured over the insular slope at Glover’s Reef, a coral atoll in Belize. The estimated total length of the individual was ca. 3.0–3.5 m and multiple morphological features diagnostic of a somniosid shark (short snout, presence of an ectoparasitic copepod on the eye, low and rounded dorsal and pectoral fins, and small eyes with posteriorly situated large spiracles) were observed. While the exact species could not be confirmed, it is most likely a Greenland shark (Somniosus microcephalus) or a hybrid between the Greenland shark and the Pacific sleeper shark (Somniosus pacificus). This is the first record of a sleeper shark in the western Caribbean region and further supports the hypothesis that these sharks, best known from polar and subpolar latitudes, occur at depth in tropical regions.