Narcetes shonanmaruae (Alcock 1890; Fujiwara et al. 2021; 140cm, typically 75cm)is the extant slickhead, a deep-sea herring related to Clupea. Anal fin entirely behind the dorsal fin, multiserial teeth on jaws, more scale rows than congeners, precaudal vertebrae less than 30, multiserial teeth on jaws, more scale rows than congeners, precaudal vertebrae less than 30, seven branchiostegal rays, two epurals, and head smaller than those of relatives. Most slickheads are benthopelagic or mesopelagic feeders of gelatinous zooplankton, but behavioural observations and dietary analyses indicate that the new species is piscivorous. |