PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 114(l):51-57. 200L Prognatholiparis ptychomandibularis, a new genus and species of the fish family Liparidae (Teleostei: Scorpaeniformes) from the Aleutian Islands, Alaska James Wilder Orr and Morgan S. Busby NOAA/National Marine Fisheries Service, Alaska Fisheries Science Center, Resource Assessment and Conservation Engineering Division, 7600 Sand Point Way NE, Seattle, Washington 98115, U.S.A. Abstract. — A new species representing a monotypic genus of liparid fishes is described from the central Aleutian Islands. The new genus differs from all known liparid genera by its strongly protruding lower jaw and prominent folds and flaps of skin on the jaws and snout. It is similar to Allocareproctus jordani and Careproctus pycnosoma, which are also moderately slender liparids with large pelvic disks, but it is further distinguished from these species by its lower meristics, more slender body, and absence of pyloric caeca. Ptychomandibu-laris also differs from Allocareproctus in its possession of an eighth preoper-culomandibular pore, absence of coronal and post-coronal pores, two epurals, and autogenous hypural plates. A single specimen of a new liparid (Fig. 1) was collected during the 1997 triennial groundfish survey of the Aleutian Islands, conducted by the Alaska Fisheries Science Center of the U.S. National Marine Fish-eries Service. The specimen was captured in Seguam Pass in the central Aleutians at 455 m depth (Fig. 2). The new species pos-sesses unique morphological features that indicate its distinctiveness as the only known member of a new genus. Methods The holotype was fixed at sea in 10% formalin-seawater solution and later trans-ferred to 70% ethanol. Counts and mea-surements follow Burke (1930) and Pitruk (1991), with the exception of pore and pec-toral-fin ray counts. Pore counts follow Stein and Andriashev (1990). In pectoral-fin ray counts, the upper lobe includes the dorsalmost ray to the ray dorsal to the shortest ray; the lower lobe includes the shortest ray in the notch to the ventralmost ray. Caudal-fin morphology and counts of dorsal-and anal-fin rays, branchiostegals, epipleural and pleural ribs, and vertebrae were obtained by examining radiographs. Osteology of the pectoral fin was not visible in radiographs. The holotype was deposited in the University of Washington Fish Col-lection (UW). Prognatholiparis, new genus Type species. — Prognatholiparis pty-chomandibularis, new species, by monoty-py-Diagnosis. — Lower jaw projecting ante-rior to upper jaw (Fig. 3); prominent flaps and folds of skin on snout, upper jaw, and ventral portion of mandible; pelvic disk large, 37.4% head length (Fig. 4); body slender, depth at pectoral-fin base 20.5% SL, depth at anal-fin origin 19.0% SL; ce-phalic lateralis pores in 2-6-8-1 pattern, cor-onal and post-coronal pores absent (Fig. 5); epurals two, fused at base; hypural plates autogenous (Fig. 6); pleural ribs present; pseudobranchiae absent; subcutaneous ge-
Prognatholiparis Ptychomandibularis, A New Genus And Species Of The Fish Family Liparidae (Teleostei : Scorpaeniformes) From The Aleutian Islands, Alaska
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