ABSTRACT
The Family Notosudidae, formerly Scopelosauridae, is a small family of oceanic, aulopiform fishes that was reviewed in depth by Bertelsen et al. (1976). Five species that resemble moderately elongated paralepidids occur in our area (4 Scopelosaurus and 1 Ahliesaurus) of this aulopiiform family. They lack photophores, all fin rays are soft; the dorsal fin has 9-14 rays, pelvic fins almost always 9 rays, anal fin 16-21 rays, pectoral fin rays 10-15, caudal fin 19 principal rays (17 branched), and an adipose fin is present. Adults are synchronous hermaphrodites. Planktonic eggs have not been identified and yolk sac larvae are rarely collected. The larvae are distinctive with little variation among species, and they transform at around 30 mm SL. The larval body is long and slender, subcylindrical in cross-section with the caudal region compressed. Snout is long & wedge-shaped. Body depth is about 6% of SL. The eyes are narrow with a posteriorly prolonged conical mass of choroid tissue, They are slightly stalked in young larvae and during development they become broader, approaching a pearshape until they are horizontal as the stalks are lost, Pectoral fins develop first, followed by caudal, anal, and adipose, with the late-developing dorsal and pelvics rarely visible in specimens smaller than 20mm SL. Pigmentation is primarily on the tail region and is diagnostic. The following key to the larvae is adapted from Bertelsen et al. (1976). Information on California Current representatives is provided by Watson & Sandknop (1996); Ozawa (1978) provides information on two Atlantic species that occur in the North Pacific as well as North Pacific species; and Balanov & Savinykh (1999) give some information on North Pacific species.
