Anoplodactylus proliferus, Arango, 2003

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 : 2753-2755

Anoplodactylus proliferus new species

(figure 11)

Type material. Holotype W, Turtle Bay , intertidal in C. prolifera , 5 October 1998; five paratypes WX, same locality as holotype.

Other material. Same locality, 5 October 1998, seven X, two W with eggs; 14 May 1999, one W, one X; 7 October 1999, one X; 4 May 2000, 20 W, 31 X. GBR, Orpheus Island, intertidal in G. rugosa , with cyanobacteria and sponges, 7 September 1998, one W. Rib Reef, reef flat, 2 m, in rubble washings, 26 November 1998, one X. Townsville, Rowes Bay, intertidal in C. prolifera , 3 November 1998, one X; 1 June 2000, 28 W, 34 X.

Diagnosis. Small species, proboscis of females with ventral protuberances, proboscis upcurved, cement gland a single short duct, auxiliary claws absent.

Description. Trunk of compact form, 1.34 mm in length, 0.9 mm wide, segmentation lines not clearly evident, dorsum smooth, crurigers separated by half their diameter, pointed tubercles on distal margins, those on the fourth pair smaller, ocular tubercle pointing anteriorly, abdomen erect; proboscis cylindrical but slightly tapering and upturned distally, proboscis in females with two proximoventral protuberances (length 0.73 mm). Chelifores as long as proboscis, scape one-segmented, single dorsodistal spine in scape, chelae right in front of the oral surface, palms with short spines and setae, fingers slender and curved, gaping when closed; ovigers sixsegmented, third segment longest, with a basal constriction, short setae on third and fourth segments, a row of long setae on the fifth segment. Legs slender; single spine on anterior and posterior margins of first coxa on third and fourth pairs of legs of males; pointed protuberances on second coxa, those in the fourth pair larger; single dorsodistal spine on femur and both tibiae; femora swollen in females. Cement gland a dorsal tube at mid-point on femur, propodus strong, with heel, two robust heel spines, developed sole spines, long claw and no auxiliary claws visible (total length third leg 3.6 mm; 0.20–0.36–0.24–0.80–0.71–0.70–0.09–0.42–0.30).

Etymology. The name makes reference to the green alga Cladophora prolifera , the microhabitat in which A. proliferus was found to be highly abundant.

Distribution. This new species is so far known from the Townsville area and some reefs of the central section of the GBR.

Remarks. The specimens of this collection agree with A. evansi Clark, 1963 in the shape of the cement gland, the genital spurs and the ventral protuberances of the female proboscis, but differ in that the trunk is not as clearly segmented, has a narrower neck, and the ocular tubercle is slightly inclined forward. The propodus is not as curved, auxiliary claws are not visible, proboscis is more tapered in these specimens and second tibia is longer. Also, there is a significant difference in size of the animals, these from North Queensland are less than half the size of A. evansi (length 3.3 mm) (Clark, 1963). Anoplodactylus erectus Cole, 1904 differs in the subcuticular extension of the cement gland and a lamina.

This is a remarkable species due to its exclusive high abundance in the green alga Cladophora prolifera from intertidal areas of Townsville. All the specimens have a broad dorsal chalky-white stripe contrasting with internal red coloration.