Cilunculus cymobostrychos, Bamber, Roger N., 2004

Bamber, Roger N., 2004, Pycnogonids (Arthropoda: Pycnogonida) from French Cruises to Melanesia, Zootaxa 551, pp. 1-27 : 8-10

Cilunculus cymobostrychos sp. nov. ( Fig. 4 )

Material: Solomon Islands: 1 male, holotype (MNHN­Py 1038), 1 male, 1 female, paratypes (MNHN­Py 1039), station CP1781, N/ O 'Alis' Campagne SALOMON 1, 08º31.2'S 160º37.7'E, 1036–1138 m, 29/09/2001; coll. Bouchet, Dayat, Warén, Richer­ IRD.

Description: trunk ( Fig. 4 A, B) relatively compact, completely segmented, dorsal rows of sinuous setae on raised posterior margins of segments; these setae finely barbed distally. Lateral processes and trunk midline without tubercles or other setae. Ocular tubercle almost totally depressed, without eyes; two small tubercles above chelifores. Abdomen fusiform, naked, articulating at base. Proboscis barrel­shaped.

Chelifores single­articled, naked, short, one third length of cephalon; chelae atrophied.

Palp ( Fig. 4 C) of nine articles, second article longest, third article half length of fourth; distal five articles subequal, together as long as second article, with rows of short ventral setae.

Oviger ( Fig. 4 A, D) of ten articles, article 2 longest, articles 4 and 5 subequal, 0.8 times length of article 2; compound oviger spines on distal three articles numbering 1:1:2.

Third leg ( Fig. 4 E, F) first coxa 0.6 times as long as second coxa and 1.5 times as long as third coxa, all three relatively glabrous; femur with numerous, sinuous setae mostly oriented proximally, and with large, tapering dorsodistal cement gland tube about twice as long as femur diameter, and dorsodistal slender spine. First tibia 1.1 times length of femur, second tibia 1,1 times length of first tibia, both with numerous sinuous setae and longer dorsodistal slender spine; tarsus compact, with three ventral spines; propodus without heel, but with two stronger heel spines, seven shorter sole spines, and distal and dorsodistal setae; main claw more than half length of propodus, auxiliary claw one fifth length of main claw.

Measurements of male (mm): trunk length (anterior of cephalon to tip of 4th lateral process) 2.19; length of cephalon 0.61; width across 2nd lateral processes 1.26; proboscis length 1.1; abdomen length 0.55; chelifore length 0.19; palp article 2 (P2) 0.6, P3 0.17, P4 0.36; third leg, first coxa 0.34, second coxa 0.56, third coxa 0.23, femur 1.55, first tibia 1.71, second tibia 1.9, tarsus 0.1, propodus 0.65, main claw 0.37, auxiliary claw 0.08; oviger article 2 ( O 2) 0.68, O 4 0.52, O 5 0.55.

Etymology: from the Greek kyma – a wave, and bostrychos – a lock of hair; the middorsal setae on the posterior rim of each trunk segment have an appearance of a human wavy hairstyle (noun in apposition).

Remarks: With its compact trunk unadorned by spines or tubercles, and truncate cephalon without ocular tubercle or eyes, Cilunculus cymobostrychos sp. nov. resembles the European species C. europaeus Stock, 1978 and C. battenae Bamber & Thurston, 1993 (see Bamber & Thurston 1995, fig. 6). The former species has similarly setose legs but a longer abdomen and auxiliary claw (>0.5 times the length of the main claw), while C. battenae has comparatively naked legs and an auxiliary claw length 0.4 of the main claw (0.2 in the present species). In the key to the genus of Stock (1997), C. cymobostrychos keys to couplet 5, then as C. battenae . However, neither that nor any other species of Cilunculus has the dorsomedian rows of wavy barbed setae on the trunk.

Figures

FIGURE 4. Cilunculus cymobostrychos sp. nov., male holotype, A, body, lateral; B, body, dorsal, with detail of seta­tip; C, left palp; D, distal oviger articles; E, third left leg; F, distal articles of third leg. Scale line = 1 mm for A, B and E, 0.45 mm for C, 0.2 mm for D and F.