FISHERY BULLETIN: VOL. 81, NO. 1 



Island by Kendall et al. (footnote 3), and for the 

 eastern Gulf of Alaska by Naplin et al. 4 



Presented here is the first published descrip- 

 tion of the development of Leuroglossus schmidti. 

 Ahlstrom (1965) presented illustrations of 5.4, 

 15.7, and 28.5 mm SL (standard length) speci- 

 mens of L. stilbius stilbius; subsequently he 5 pre- 

 sented illustrations of, but did not publish, a size 

 series (8.4, 20.5, and 31.5 mm SL)of L. schmidti. 

 Ahlstrom (1969) also described the eggs of L. 

 schmidti, L. s. stilbius, and L. s. urotranus and 

 presented supporting arguments for recognizing 

 L. schmidti as a distinct species. Differences of 

 opinion exist over the correct name of L. schmidti 

 (Ahlstrom 1965, 1969; Borodulina 1968), its spe- 

 cific status (Hart 1973; Peden 1981), and the va- 

 lidity of the genus Leuroglossus Gilbert (Cohen 

 1956, 1964; Ahlstrom 1968, 1969; Borodulina 

 1969). I also attempt here to resolve the nomen- 

 clature of L. schmidti, to confirm the validity of 

 the genus Leuroglossus Gilbert, and to describe 

 the known distribution of eggs and larvae of this 

 species in the northeast Pacific Ocean and east- 

 ern Bering Sea. 



Relatively little is known about the biology of 

 the northern smoothtongue. Adult L. schmidti 

 have been taken at the sea surface as well as at 

 depths to 700 m, and larval and juvenile speci- 

 mens have been found in the stomachs of several 

 species of fish (Hart 1973). 



METHODS 



Specimens 



Larvae and juveniles of Leuroglossus schmidti 

 were obtained from plankton samples collected 

 by the Northwest and Alaska Fisheries Center 

 (NWAFC) in the eastern Bering Sea in 1971 and 

 1976-79 and from the Gulf of Alaska in 1971, 

 1972, and 1977-79. Several hundred specimens 

 were examined in the course of this study. Addi- 

 tional juvenile specimens were obtained from the 

 collections in the College of Fisheries, University 

 of Washington (UW). Radiographs of L. schmidti 



4 Naplin, N. A., J. R. Dunn, and K. Niggol. 1973. Fish 

 eggs, larvae, and juveniles collected from the northeast Pacific 

 Ocean, October-November, 1971. Unpubl. manuscr., 83 p. 

 Northwest and Alaska Fisheries Center, National Marine 

 Fisheries Service, NOAA, 2725 Montlake Blvd. East, Seattle, 

 WA 98112. 



5 E. H. Ahlstrom (deceased), Southwest Fisheries Center La 

 Jolla Laboratory, National Marine Fisheries Service, NOAA, 

 La Jolla, CA 92038, class notes taken by the author in August 

 1971. 



were made from juvenile specimens in collec- 

 tions at NWAFC; additional radiographs were 

 obtained from the College of Fisheries, UW. 



Comparative material consisting of larvae and 

 juveniles of Bathylagus pacificus, B. ochotensis, 

 B. milleri, and L. stilbius stilbius was obtained 

 from collections at the NWAFC and College of 

 Fisheries, UW. Radiographs and cleared and 

 stained specimens of B. ochotensis, B. nigrigenys, 

 B. milleri, B. wesethi, B. bericodes, B. longiros- 

 tris, and L. stilbius stilbius were examined from 

 collections at the Southwest Fisheries Center 

 (SWFC), NMFS, La Jolla, Calif. 



Measurements 



The following measurements were made on 

 152 unstained larvae and juveniles, 4.9-55.0 mm 

 SL, using an ocular micrometer in a stereomicro- 

 scope. 



Standard length = snout tip to notochord tip until 

 notochord is fully flexed and the posterior mar- 

 gin of the forming hypural bones is vertical, 

 then to posterior margin of hypurals. 



Snout to anus = horizontal distance along mid- 

 line of body from tip of snout to vertical through 

 posterior edge of the anus. 



Head length (HL) = horizontal distance from tip 

 of snout to posterior margin of cleithrum until 

 no longer visible, then to posteriormost margin 

 of opercle. 



Snout length = horizontal distance from tip of 

 snout to anterior margin of pigmented region 

 of eye. 



Interorbital width = width of fleshy tissue dorsal 

 to the eyes. 



Eye width = horizontal distance through midline 

 of pigmented eye. 



Eye height = vertical distance through center of 

 pigmented eye. 



Body depth at pectoral fin base = vertical 

 distance across body at pectoral fin base. 



Body depth at anus = vertical distance across 

 body at anus. 



Snout to origin of dorsal f in = horizontal distance 

 along midline of body from tip of snout to ver- 

 tical from origin of dorsal fin. 



Snout to origin of anal fin = horizontal distance 

 along midline of body from tip of snout to ver- 

 tical from origin of anal fin. 



Snout to origin of pelvic fin = horizontal distance 

 from tip of snout to vertical through origin of 

 pelvic fin. 



24 



