Endeis leviseminentia, Takahashi & Dick & Mawatari, 2007

Takahashi, Yoshie, Dick, Matthew H. & Mawatari, Shunsuke F., 2007, Sea spiders (Arthropoda: Pycnogonida) from waters adjacent to the Nansei Islands of Japan, Journal of Natural History 41 (1 - 4), pp. 61-79 : 64-66

Endeis leviseminentia sp. nov.

( Figure 2 )

Material examined. Holotype: male, ZIHU 03167 , 26 ° 14.63 9 N, 127 ° 31.79 9 E, south of Nagannu Island , Okinawa, 26 May 2002, 52 m depth; collected by dredge; Y. Takahashi, collector.

Etymology. The species name leviseminentia (Latin, levis, meaning little, and eminentia, meaning protuberance) refers to the small dorsal protuberance on the second trunk segment.

Measurements of holotype (mm). Trunk length, 6.5; body width, 2.0; proboscis length, 3.6; length of abdomen, 0.9; third leg, coxa 1, 0.45; coxa 2, 2.45; coxa 3, 0.75; femur, 5.45; tibia 1, 5.0; tibia 2, 6.5; tarsus, 0.15; propodus, 1.1; main claw, 0.5; auxiliary claw, 0.4; oviger first article (O1), 0.54; O2, 1.07; O3, 0.55; O4, 0.88; O5, 0.91; O6, 0.64; O7, 0.41.

Description. Size large for genus; leg span about 22 mm. Trunk ( Figure 2A, B ) elongate, with small, mid-dorsal protuberance on second segment, protuberance shorter than wide. Lateral processes less than 1.5 times as long as their maximum width, separated by three or slightly more times their width; each armed with sharp-pointed tubercle dorsodistally. Ovigers inserted immediately anterior and ventral to bases of first lateral processes, touching them. Ocular tubercle about the same height as its basal width, dome-shaped with a small distal knob; eyes pigmented and situated basally on ocular tubercle. Abdomen less than 1.5 times as long as wide, cylindrical proximally, tapering to a blunt cone distally, without setae.

Proboscis ( Figure 2A, B ) straight, two-thirds as long as trunk, finely setose on all sides, narrowest proximally and gradually thickening distally, with a pronounced swelling proximal to middle and comprising about one-quarter the length; cylindrical at the tip, widest both at the swelling and at distal end, which is less than 1.5 times as wide as the base. Chelifores and palps absent.

Ovigers ( Figure 2C 1 ) seven-segmented; second segment longest, about twice as long as first segment; third and sixth segment subequal, both a little longer than first segment; fourth segment and curved fifth segment subequal; sixth segment thickened and ovoid; seventh segment tapering distally. Proximal six segments of oviger armed with short pointed setae that are directed proximally in distal segments; sixth segment with four low protuberances each bearing short seta; seventh segment without setae but with tiny rounded spines, four at apex ( Figure 2C 3 ), three endally, and four between others ( Figure 2C 2 ).

Legs ( Figure 2D ) long and slender. First coxa short, armed with pointed, slightly curved dorsodistal tubercle, much larger than but similar in form to lateral process tubercle. Second coxa elongate, about five times as long as first coxa, sparsely setose on all sides. Third coxa less than twice length of first coxa, with single seta dorsally and densely, finely setose ventrally. Femur finely setose dorsally and ventrally, and with spine groups on dorsodistal median tubercle and adjacent smaller tubercle; 27–30 short tubular cement gland openings ( Figure 2E ) in a regular row. First tibia slightly shorter and second tibia longer than femur; both tibiae setose, with several larger setae intermingled, and armed with distal spines: one dorsolateral spine on tibia 1, three ventral spines on tibia 2. Tarsus short, convex ventrally with single large spine surrounded by smaller spines, few dorsal spines. Propodus ( Figure 2F ) gradually curving, setose, with large distal setae; heel with four large ventral spines and pair of smaller spines distally; sole with nine or 10 smaller spines and single long distal seta; main claw slightly less than half length of propodus, the long edge curved and the short edge nearly straight; auxiliary claw nearly two-thirds as long as main claw, curving distally.

Remarks. In overall appearance, Endeis leviseminentia sp. nov. is similar to both E. procera ( Loman, 1908) and E. pauciporosa Stock, 1970 , particularly in having an elongate trunk and long legs, and in the shape of the proboscis. Endeis procera is distributed in Philippine and Indonesian waters, near the area of our survey. However, E. leviseminentia differs from E. procera in having dorsal tubercles on both the lateral processes and first coxae, a dorsal median process on the second trunk segment, several spine groups mounted on the swellings of the femur, and relatively setose tibiae 1 and 2. Endeis leviseminentia is similar to E. pauciporosa in also having dorsal tubercles on the lateral processes, but it differs in the following characters (characters of E. pauciporosa in parentheses): straight femur with short setae (distorted, long), wide gap between adjacent lateral processes (narrow), and 27–30 cement gland pores (six to seven) per femur. Almost all Endeis species have multiple cement gland pores situated in one or two rows on the posterior side of each femur. In E. leviseminentia , 27–30 cement gland pores, each of tubular form with tapering tip, are arranged in a single regular row. Tubular pores have been previously reported in only one species, E. spinosa ( Montagu, 1808) , but these are not tapering, 19–26 in number, and arranged in irregular rows on a distorted femur with long setae ( King 1974).

Distribution. Known only from the type locality, south of Nagannu Island, Okinawa, 52 m depth.

Figures

Figure 1. (Above) map of Japan showing the location of the Nansei Islands (box); (below) enlargement of box, showing the Nansei Islands and the collecting sites (filled circles).

Figure 2. Endeis leviseminentia sp. nov., holotype, male: (A) trunk, dorsal view; (B) trunk, lateral view; (C1) oviger; (C2) enlargement of distal end of oviger; (C3) enlargement of distal spines of oviger; (D) third leg; (E) enlargement of cement gland; (F) enlargement of distal segments of third leg. Scale bars: 1 mm (A–D, F); 0.1 mm (E).

Figure 3. Rhopalorhynchus tenuissimum (Haswell, 1884), male, except for C: (A) trunk, dorsal view; (B) trunk, lateral view; (C) proboscis, lateral view, female; (D) palp; (E) oviger; (F) strigilis, with enlargements of two types of spines; (G) third leg. Scale bars: 1 mm (A–E, G); 0.5 mm (F).