245 



Abstract— Psednos rossi new species 

 (Teleostei: Liparidaei is described from 

 two specimens collected in the North 

 Atlantic Ocean off Cape Hatteras, 

 North Carolina, at depths of 500- 

 674 m. Psednos rossi belongs to the 

 P. christinae group, which includes 

 six other species and is characterized 

 by 46-47 vertebrae and the absence 

 of a coronal pore. Psednos rossi dif- 

 fers from those six species by having 

 characters unique within the genus: 

 straight spine, body not humpbacked 

 at the occiput, and a very large mouth 

 with a vertical oral cleft. Other distin- 

 guishing characters include a notched 

 pectoral fin with 15-16 rays, eye 

 17-19% SL, and color in life orange- 

 rose. With P. rossi, the genus Psednos 

 as currently known includes 26 de- 

 scribed and five undescribed species of 

 small meso- or bathypelagic liparids 

 from the Atlantic. Pacific, and Indian 

 Oceans. 



A remarkable new species of Psednos 

 (Teleostei: Liparidae) from the 

 western North Atlantic Ocean 



Natalia V. Chernova 



Zoological Institute 



Russian Academy of Sciences 



Unlversitetskaya nab- 1 



St. Petersburg 199034. Russia 



David L. Stein 



NOAA/NMFS Systematlcs Laboratory 



Smithsonian Institution 



P.O. Box 37012 



National Museum of Natural History, MRC-0153 



Washington, DC. 20013-7012 



E-mail address (for D L. Stem, contact author): david.stenvanoaa gov 



Manuscript approved for publication 

 7 January 2004 by Scientific Editor. 



Manuscript received 20 January 2004 

 at NMFS Scientific Publications Office. 



Fish. Bull. 102:245-250 (2004). 



The liparid genus Psednos Barnard 

 1927 is a group of meso- and bathype- 

 lagic snailfishes distinguished from the 

 genus Paraliparis by having the infra- 

 orbital canal of the cephalosensory 

 system interrupted behind the eye and 

 usually having a pronounced dorsal 

 curvature of the spine, producing a 

 "humpbacked" body. Psednos are small, 

 easily damaged, and often misidenti- 

 fied as juvenile Paraliparis. Until 1978, 

 the genus was known only from two 

 specimens of a single species (Psednos 

 micrurus Barnard 1927) collected off 

 Cape Point, South Africa. Two addi- 

 tional specimens were collected in the 

 southern Indian Ocean and reported 

 by Stein (1978). No further specimens 

 or species were described until Andria- 

 shev (1992) described another new 

 species. Since then, active searches for 

 material from collections around the 

 world have yielded many specimens 

 from the Atlantic. Pacific, and Indian 

 Oceans. To date, 25 species have been 

 described (Andriashev, 1992, 199.3; 

 Chernova. 2001; Stein et al.. 2001; 

 Chernova and Stein, 2002) and an 

 additional five are undescribed (one in 

 Stein et al., 2001, three in Chernova 

 and Stein, 2002, all in poor condition; 

 and another that is currently being 

 described by Stein). In this article, we 

 describe an especially noteworthy spe- 



cies of the genus from two specimens 

 collected from the North Atlantic off 

 Cape Hatteras, North Carolina. 



Materials and methods 



All characters available for both speci- 

 mens were studied. Characters and 

 terms used were described by Andria- 

 shev (1992), Chernova (2001), Stein 

 et al. (2001), and Chernova and Stein 

 (2002 1. Counts were made from a radio- 

 graph of the holotype and from each 

 specimen where possible; vertebral 

 counts include the urostyle. The first 

 caudal vertebra is that with the haemal 

 spine supporting the first anal-fin ray. 

 The posterior tip of the lower jaw in 

 Psednos forms a distinct and promi- 

 nent ventrally directed angle, the ret- 

 roarticular process (Chernova, 2001). 

 Counts and proportions are given as a 

 percentage of standard length ( SL) and 

 head length (HL). Nonstandard mea- 

 surements are the following: distance 

 from mandible to anus (from ante- 

 rior tip of mandible to center of anus); 

 distance from anus to anal-fin origin 

 (from center of anus to anal-fin origin); 

 interorbital width (measured between 

 upper margins of eyes); postocular 

 head length (distance from posterior 

 margin of eye to tip of opercular flap). 



