Prolanceola vibiliformis Woltereck, 1907

Zeidler, Wolfgang, 2009, A review of the hyperiidean amphipod superfamily Lanceoloidea Bowman & Gruner, 1973 (Crustacea: Amphipoda: Hyperiidea), Zootaxa 2000, pp. 1-117 : 66-70

Prolanceola vibiliformis Woltereck

( Figs 23 & 24)

Prolanceola vibiliformis Woltereck, 1907: 130–132 , fig. 1. Woltereck 1909: 157, pl. 5, figs 14, 15. Bulycheva 1955: 1048 (table). Vinogradov 1957: 198, figs 7, 8; 1960a: 211; 1964: 118; 1970: 384 (table), 393. Vinogradov et al. 1982: 88–89, figs 29, 30. Barkhatov & Vinogradov 1988: 245 (table).

Type material. The unique male holotype could not be found in any major European museum and is considered lost. The type locality is the Indian Ocean, near the Cocos Islands [10°08’S 97°14’E]; Valdivia Stn. 182 (?) .

Material examined. North-West Atlantic : Female ( ZMUC); S.W. of Cape Verde Is. [12°11’N 35°49’W]; Dana Stn. 1165 VII , 4000 mw, 9 Nov. 1921 . Two females ( ZMUC); N. of Brazil [08°19’N 44°35’W]; Dana Stn. 1171 , 4500–0 mw, 13 Nov.1921 . South–East Atlantic : Female ( ZMUC); off South Africa [23°26’S 03°56’E]; Dana Stn. 3980 VIII, 4000 mw, 17 Feb. 1930 . Male , three females ( ZMUC); N. of St. Helena [07°34’S 08°48’W]; Dana Stns 3998 VII, VIII & IX, 5000, 4000 & 3000 mw, 1 Mar. 1930 . Two females ( ZMUC); S. of Liberia [00°31’S 11°02’W]; Dana Stns 4000 VII & VIII, 5000 & 4000 mw, 4 Mar. 1930 . South-West Pacific : Female ( ZMUC); Tasman Sea [33°33’S 154°04’E]; Dana Stn. 3663 II, 4000 mw, 23 Feb. 1929 . Central South Pacific : Female ( ZMUC); S. of Tahiti [18°19’S 153°10’W]; Dana Stn. 3577 VII, 4000 mw, 19 Oct. 1928 . Indo-Pacific : Female ( ZMUC); Banda Sea [05°52’S 131°14’E]; Dana Stn. 3676 IX, 3000 mw, 23 Mar. 1929 . East Indian : Female ( ZMUC); S.W. of Maldive Is. [01°45’N 71°05’E]; Dana Stn. 3917 II, 3700 mw, 5 Dec. 1929 .

Diagnosis. Body length up to 14 mm. Cuticle with distinct hexagonal markings. Head without rostrum or slightly produced upwards and forwards medially; with slight depression dorsally and small lateral ridge; similar in length to first pereonite. Pereon not inflated. Pereon and pleon with slight dorsal keel. Pereonites, pleonites and first pleonite with lateral ridge. Eyes consist of chain of five, sub-cuticular, ocelli extending dorsally from usual eye position on side of head, in groups of two and three. Antennae 1 as long as head and first two pereonites combined (slightly shorter in females); callynophore relatively large, in males proximally as broad as peduncle, in females much narrower than peduncle tapering gradually; terminal two articles narrow, much longer than wide, preceding article as long as wide. Antennae 2 almost as long as head and first five pereonites combined (a little shorter in females), about 1.6x length A1. Gnathopod 1 subchelate, with distally expanded carpus; propodus produced distally into rounded lobes above and below insertion of dactylus; merus relatively bulbous. Pereopod 3 slightly shorter than P4; basis length more than twice merus (including anterodistal lobe); ischium with prominent anterior bulge; merus with anterodistal corner produced into lobe overlapping proximal part of carpus, slightly shorter than carpus; propodus slightly longer than carpus; dactylus length about 0.2x propodus. Pereopod 4 similar in structure to P3 but basis relatively shorter; anterior bulge of ischium not as prominent; merus, carpus and propodus relatively longer but of similar proportions. Pereopod 5 slender, length 1.6x P4; basis as long as merus; carpus length about half merus, anterodistal corner produced and distal margin indented for insertion of propodus; propodus length 0.4x carpus; dactylus short, curved, inserted subterminally but not retractile(?). Pereopod 6; length 0.6x P5; basis rectangular, length 1.5x merus; merus expanded distally with posterodistal corner produced into short, rounded lobe; carpus slightly shorter than merus; propodus length 1.2x carpus, without spoon-shaped process but with hollow for small, retractile dactylus. Pereopod 7 similar to P6 but slightly shorter; with small round/oval-shaped, flat appendage, fringed with fine setae, located medially at base next to coxa; basis length 1.5x merus; merus slightly expanded distally as in P6; carpus length 0.7x merus; propodus length 1.3x carpus; dactylus inserted as for P6. Peduncles and rami of U1 & 2 relatively broad. Uropod 3; peduncle width 0.8x length. Telson slightly longer than peduncle of U3; relatively narrow, width at base 0.4x length.

Colour, according to water-colour paintings by K. Stephensen (in ZMUC) of female from Dana Stn. 1171 ; pale red-pink with slightly darker pereon and pereopods. According to Vinogradov & Semenova (1996), “opaque, monotone rose red or dark wine-red”.

Remarks. This seems to be a very rare species having been recorded in the literature only nine times previously, from ten or eleven specimens. The Dana collections comprising thirteen females and one male thus represent the largest single collection of this species. Prior to this study only two males (including the lost type) were known. Thus, the male from the Dana collections is illustrated here. A mature female was illustrated and described by Vinogradov (1957).

Distribution. A widely distributed, although rare, species. Previously recorded from the Indian Ocean near Cocos Islands and south of the Seychelles and from the Pacific Ocean ranging from the Kurile- Kamchatka region to subantarctic waters [43°S 158°E] ( Barkhatov & Vinogradov 1988). The Dana collected it from all major oceans with new records for the Atlantic, Indo-Pacific and Tasman Sea. The latter is also a new record for Australian waters. It seems to prefer deeper waters having been caught in the 1500–2000 m layer in the Kurile-Kamchatka region ( Vinogradov 1970) and in catches from depths of more than 2000 m to the surface. Similarly, all of the Dana collections of this species were made with more than 3000 m of wire.