Achelia orpax Nakamura & Child 1983

Achelia orpax

Material Examined.—Sagami Bay: Off Shimoda, 8 Aug 1973 (1, holotype, USNM 183800).

DESCRIPTION.—Trunk compact, circular in outline, unsegmented. Lateral processes contiguous proximally, slightly separated distally, each armed with long dorsodistal tubercle bearing several barbed or feathered large spines laterally and distally. Cephalic segment with tubercles over chelifore insertion, armed with feathered spines. Ocular tubercle at extreme anterior of cephalic segment, more than twice as tall as its diameter, rounded distally, with tiny apical cone. Eyes darkly pigmented, placed at tip of ocular tubercle. Proboscis large, barrel-shaped, subequal in length to trunk. Abdomen long, extending to second coxae tips of fourth legs, armed with several pairs of large feathered spines and several small distal setae.

Chelifore scape long, slightly curved, armed with many dorsal and lateral long feathered spines and several short distal setae, spines more than twice as long as segment diameter. Chela globular, without fingers, armed with single lateral feathered spine.

Palp 8-segmented, second and fourth segments subequal in length, armed with short feathered spines distally. Four terminal segments only slightly longer than wide, armed with many short feathered spines laterally and ventrally. Palp spines shorter than segment diameter.

Oviger 10-segmented, segments short, seventh and eighth armed with single dorsodistal seta. Strigilis weak, armed with denticulate spines in the formula 2: 2: 3: 2, each with 5 or 6 lateral serrations.

Legs moderately stout. Third leg, first coxa armed with dorsolateral feathered spines and tall dorsodistal tubercle armed with several feathered spines. Second coxa armed with several lateral and many ventrodistal feathered spines. Third coxa armed with several short ventral setae and fringe of long feathered spines distally. Femur equal to tibia 1 in length, inflated, armed with 6 dorsal and many ventral and distal feathered spines of various lengths. Both tibiae armed with many long dorsal and dorsolateral feathered spines and a few lateral and ventral setae. Tarsus short, quadrangular, armed with several ventral setae and a single dorsal seta. Propodus slender, well curved, armed with 3 large heel spines, 7 or 8 small sole spines, 3 dorsodistal feathered spines and several short dorsal and lateral setae. Claw half propodal length, well curved. Auxiliaries about two-thirds main claw length.

MEASUREMENTS OF HOLOTYPE (mm).—Trunk length, 1.04; trunk width, 1.09; proboscis length, 1.01; abdomen length, 0.92; third leg, coxa 1, 0.37; coxa 2, 0.46; coxa 3, 0.4; femur, 0.96; tibia 1, 0.97; tibia 2, 0.67; tarsus, 0.14; propodus, 0.6; claw, 0.3.

ETYMOLOGY.—The specific name orpax is from the Greek and means a sapling or young shoot, in reference to the many feathered spines covering much of this species.

DISTRIBUTION.—Known only from the type-locality off Shimoda, Izu Peninsula, in 30 meters.

Achelia orpax là một loài nhện biển trong họ Ammotheidae. Loài này thuộc chi Achelia. Achelia orpax được miêu tả khoa học năm 1983 bởi Nakamura & Child.

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