Nymphon micronesicum Child, 1982

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 : 2739

Nymphon micronesicum Child, 1982

(figure 7)

Nymphon micronesicum Child, 1982b: 277–280 , figure 3; 1988a: 68.

Material examined. Pandora Reef, 5 m, on fouled rubble, 28 October 1999, one juvenile; 6 m, 19 April 2000, 22 W, 24 X, 11 juveniles.

Description. Trunk length 1.68 mm, width 0.6 mm, fully segmented, smooth; crurigers separated by almost their own diameter, glabrous, neck with a marked constriction; ocular tubercle with two tiny tips on apex; abdomen erect, long; proboscis cylindrical, slightly tapering distally. Scape one-segmented, with dorsal row of setae, palm globular in males, elongated in females, fingers short, stout, only a small gap at base when closed, both fingers denticulate with 10–12 bifurcate teeth each, fingers placed at right angle with the palm. Last palpal segment longer than third, subequal to second. Ovigers 10-segmented, fifth segment the longest, formula 12:12:11:10, dimorphic spines on ninth segment; terminal claw without denticulations. Legs long, slender, second tibia with rows of fine setae; propodus straight, elongate without heel, with few spines, claw small, auxiliaries longer than main claw by one-fifth of its length. Cement glands not found.

Distribution. This species described from Micronesia is part of a complex of very similar species, the aequidigitatum -group (Child, 1988a) with a wide distribution, mainly in shallow waters of the Indo-Pacific and the Caribbean. Nymphon micronesicum had not been reported from Australia before and appears as a coral reef species so far.

Remarks. Nymphon micronesicum can be separated by the combination of the terminal palp segment longer than other segments, oviger claw smooth, rugosities in main and auxiliary claws, and chelae fingers with bifurcate teeth. Geographically, its closest relative would be N. draconis Child, 1990 from Lizard Island, North GBR, characterized by shorter trunk and neck and conspicuous femoral cement glands.