Oidiphorus mcallisteri Anderson, 1988

M. Eric Anderson, 2006, Studies on the Zoarcidae of the southern hemisphere. X. New records from western Antarctica., Zootaxa 1110, pp. 1-15 : 9-10

Oidiphorus mcallisteri Anderson, 1988

Oidiphorus mcallisteri Anderson, 1988: 102 , figs. 8B, 38 (type locality: off South Georgia ); Anderson, 1990b: 272, fig. 19.

Material examined. USNM 356656 (1 specimen; 114 mm SL), Scotia Sea, W. of South Orkney Islands , 60°45.5'S, 48°13.5'W, 2511-2542 m, ISLAS ORCADAS coll. UMO 116, 10 ft beam trawl, 18 Feb. 1976, H. H. DeWitt.

Diagnosis. Oidiphorus mcallisteri is distinguished from its only congener, O. brevis , by the following combination of characters: pelvic fins present; preoperculomandibular pores 7; suborbital pores 5; pectoral fin rays 14-17; precaudal vertebrae 18; dorsal fin origin associated with vertebrae 3-4.

Description. Vertebrae 18 + 51 = 69; D 64; A 52; P 16; C 7; pelvics 2; branchiostegal rays 6; gill rakers 1 + 7; vomerine teeth 11; palatine teeth 9/9; pseudobranch and pyloric caeca absent; preoperculomandibular pores 7; suborbital pores 5 + 0; postorbital pores 2; supraorbital (nasal) pores 2; occipital and interorbital pores absent. Following proportions as percent SL: head length 20.8; head width 12.5; head depth 11.5; predorsal length 21.1; preanal length 41.2; pectoral base depth 6.8; pectoral-fin length 12.5; body depth 9.3; gill slit length 9.2. Following proportions as percent HL: head width 60.3; head depth 42.2; upper jaw length 51.1; snout length 23.2; eye diameter 21.9; gill slit length 44.3; pectoralfin length 60.3; pelvic-fin length 19.8; caudal-fin length 33.8; interorbital width 15.6; interpupillary width 30.8. Pectoral base/length ratio: 53.9%.

Dorsal edge of gill cover forming horn-like projection when pulled forward owing to subopercular ramus projecting well above opercle, characteristic of Oidiphorus . Single, low pyramidal papilla between each mandibular and suborbital pore, none on cheeks or top of head. First gill arch with single, miniscule raker on upper limb, unlike types. Lateral line mediolateral, difficult to trace in this faded specimen ( Anderson, 1988, mistakenly stated lateral line to be absent).

Remarks. This is the third known specimen of O. mcallisteri and is slightly larger than the two types ( Anderson, 1988), but agrees well with them in all respects. It is a ripe female and had 33 ova 1.5-2.2 mm in diameter, 23 of them 2.0 mm or larger.