Revision of the snailfish genus Allocareproctus Pitruk & Fedorov (Teleostei: Liparidae), with descriptions of four new species from the Aleutian Islands

• Published in: Zootaxa
• Main Authors: ORR, JAMES W., BUSBY, MORGAN S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Mangolia Press 2006
• Subjects: Pisces; Liparidae; snailfishes; North Pacific Ocean; Aleutian Islands; taxonomy; morphology; new species; Allocareproctus jordani.; Pacific; Alaska
• Online Access: https://www.mapress.com/j/zt/article/view/zootaxa.1173.1.1; https://doi.org/10.11646/zootaxa.1173.1.1

Liparid fishes of the genus Allocareproctus Pitruk & Fedorov were collected throughout the Aleutian Islands during surveys conducted by the Alaska Fisheries Science Center, U.S. National Marine Fisheries Service, and represent the first documented records of this genus in North America. Based on this material, we revised the genus and recognized four new species described herein. Allocareproctus is distinguished from all other liparid genera by the following characters: anterior 4–8 dorsal-fin rays with tips exserted from the fin membrane, papillae associated with some pores of the cephalic lateralis system, and symplectic extending to the medial aspects of thequadrate and metapterygoid. Allocareproctus jordani (Burke), the type species of the genus, is uniformly pink-red in coloration, with a dark peritoneum, simple teeth, a pigmented nasal papilla, and a single lobe on the orobuccal valve. It ranges from Sagami Bay, the type locality, north through the Kuril Islands, and east to Umnak Island of the Aleutian Islands, at depths of 75 to 495 m. Allocareproctus ungak n. sp. is most similar to A. jordani, differing in having trilobed teeth, an unpigmented nasal papilla, and higher counts of median-fin rays and vertebrae. It is found only between Seguam Pass and Samalga Pass in the east-central Aleutian Islands at depths of 318 to 461 m. Allocareproctus kallaion n. sp. is also known only from Seguam Pass and Samalga Pass at depths of 278 to 450 m and is distinguished from all other species of Allocareproctus by its blotchy red body color in life and dusky head coloration in life and in preservation, high gill raker count, high precaudal vertebrae count, and comb-like orobuccal valve. Allocareproctus tanix n. sp. is most similar to A. unangas n. sp. and is distinguished by its orange-peach coloration, pale peritoneum, absence of an interorbital papilla, and greater body depth. It is found only in the central Aleutians at depths of 104 to 650 m. Allocareproctus unangas n. sp. is also found only in the central Aleutians at similar depths of 210 to 465 m and is distinguished by its trilobed teeth, absence of a nasal papilla, and dark peritoneum. Based on our examination of holotypes, Careproctus pycnosoma Gilbert & Burke and C. curilanus Gilbert & Burke are valid species and not synonymous with A. jordani.