Anoplodactylus batangensis (Helfer, 1938)

Arango, Claudia P., 2003, Sea spiders (Pycnogonida, Arthropoda) from the Great Barrier Reef, Australia: new species, new records and ecological annotations, Journal of Natural History 37 (22), pp. 2723-2772 : 2747-2748

Anoplodactylus batangensis (Helfer, 1938)

Pycnosoma batangense Helfer, 1938: 174–176 , figure 6a–c.

Anoplodactylus batangensis: Stock, 1953b: 39–41 , figure 4; 1954: 54; 1968: 54; 1975b: 1082, figure 43c, d; 1994: 54; Arnaud, 1973: 957, figures 3, 4; Child, 1975: 191; 1977: 444; 1982a: 368; 1988b: 14; 1990: 327; 1992: 41–42, figure 18; 1996b: 549; 1998a: 293; Müller, 1990: 283; 1992: 47; Bamber, 2000: 613.

Material examined. Turtle Bay , intertidal C. prolifera , 27 March 1997, one X, 44 juveniles (coll. Otto); 5 October 1998, two W, seven X, one juvenile ; 12 July 1999, one W, one X; 4 May 2000, three X; 1 July 2000, one W with eggs. GBR, Orpheus Island , Pioneer Bay, intertidal seagrass bed and filamentous algae, 7 September 1998, one juvenile .

Description. Trunk length 0.82 mm, width 0.36 mm, lines of segmentation just visible; crurigers separated by about half their diameter. Ocular tubercle inclined to the front, truncate tip, eyes well-pigmented; proboscis upturned, tapering distally. Abdomen erect, about same height as ocular tubercle. Scape one-segmented, chelifores touching each other, palm with short setae. Ovigers typical. Legs robust, with irregular margins, ventral genital spur on the second coxa of the fourth pair of legs of males, single dorsodistal long spine on femur and tibiae, cement gland a dorsal tube; propodus large, curved, robust, with strong heel, two heel spines, five to six sole spines.

Distribution. In Australia this species had been reported once from Lizard Island (Child, 1990). It has been found in almost every tropical collection of pycnogonids world-wide. It is considered a pantropical species in littoral and shallow depths.

Remarks. It is recognized by the slender styliform, up-curved proboscis, unique in the genus. Stock re-described the type specimen annotating the tricuspidate tip of the ocular tubercle and with no pigmented eyes (Stock, 1953b), differing from the characteristics described above. Anoplodactylus batangensis has been reported with a dorsal chalky stripe from the base of the ocular tubercle to the base of the abdomen (Child, 1982a). The specimens in this collection do not display such pattern but have a pale pink cuticle. Surprisingly, that description of colour in A. batangensis by Child resembles more the pattern I observed in A. proliferus (see below).