Colossendeis colossea Wilson, 1881

Staples, David A., 2007, A new species of Colossendeis (Pycnogonida: Colossendeidae) together with records from Australian and New Zealand waters, Memoirs of Museum Victoria 64, pp. 79-94 : 87-88

Colossendeis colossea Wilson, 1881

Figures 2A–J , 7A , Table 1.

Colossendeis colossea Wilson, 1881: 224–246 , pl.1, fig. 1, pl. 3, figs 5–7— Fry and Hedgpeth 1969: 53–54 [earlier literature], fig. 8— Stock, 1975: 987; Stock, 1987: 508 (literature)— Bamber and Thurston,

1993: 859; Bamber and Thurston, 1995: 143–144, 147— Child, 1994: 10–11; Child, 1995: 76; Child, 1998: 56–57 —Bamber, 1995: 147.

Material examined. Western Australia. 80 km WNW of Green Head, from 29°51.9'S, 114°11.6'E, bottom 770 m, to 29°50.3'S, 114°10.9'E, bottom 760 m, Western Deep-Water trawl, RV Southern Surveyor, M. F. Gomon and CSIRO, 7 Feb 1991 ( SSO1 /1991 stn 62), NMV J40745 (2 specimens) . NW Australia, 20°95.01'S, 114°.01.58'E to 20°98.82'S, 113°99.38'E, 1018 m, Benthic Dredge, RV Southern Surveyor , CSIRO, 9 Jun 2007, (SS05/07 stn 002), NMV J55743 (1 specimen) . NORFANZ Lord Howe Rise , 32° 03.98'S, 159°52.80'E, 1934 m, Ratcatcher bottom trawl, 24 May 2003, (Tan 0308, stn 071), NMV J48818 (1 specimen) . West Norfolk Rise, Wanganella Bank , 35°35.83'S, 169°33.43'E, 1760 m, Ratcatcher bottom trawl, 5 Jun 2003, (Tan 0308, stn 167), NMV J53079 (4 specimens) . Lord Howe Plateau , 32°25.94'S 161°47.62'E, 1132 m to 32°25.08'E 161°44.31'S, 1197 m, Ratcatcher bottom trawl, 24 May 2003, (Tan 0308, stn 73), MNZ PY.55 (2 specimens) . South Australia. Approx 80 n miles SW of Cape du Covedic, Kangaroo I. from 36°38'S, 137°08.20'E, to 36°30'S, 137°20'E, 1000–1200 m, trawled, FV Adelaide Pearl, K.J. Olsson, Aug 1988, SAM E3389 (2 fragmented specimens) . Tasmania. E of Piccaninny Point, Tasman Sea, 41°40'S, 148°41'E, 1097 m, amongst orange roughy haul, FV Pacific Dynasty, (no date), AM P6111 (1 specimen) .

Diagnosis based on specimens in this collection: A large species. Trunk smooth, unsegmented, lateral processes clearly separated. Proboscis straight, bottle-shaped, 1.7–1.9 times length of trunk, 5.8–6.8 times as long as greatest width, basal third narrowest, mid-region swollen, slightly tapering to 1.1–1.4 times basal width at tip. Abdomen articulated, clavate, 13–18% of trunk length. Palp segment 3 longest, segment 10 very slender, length 7.5–9.3 times median width, tapering evenly to rounded tip. Oviger claw and segment 10 coalesced; length of segment 10, 4.3–5.2 times distal width and conspicuously tapered to form a continuum with terminal claw.

Expanded description based on specimens in this collection. First lateral processes inclined and the cephalon angled downwards at about 45°. 2nd and 3rd lateral processes separated by one-quarter to one-third basal widths. Post-ocular mound low and lacking the internal tubules found in the surrounding cuticle. two eyes unpigmented in preserved material. Ocular tubercle variable, either conical or broad in anterior view, with or without small mid-dorsal papilla; lateral sensory organs well-defined. Palp segment 3, 1.1–1.2 times as long as segment 5; segment 7 about twice segment 6, 1.9–2.1 times segment 8; segment 8, 1.1–1.4 times as long as segment 9; segment 10, 1.0–1.4 times length of segment 9, segment 10 with 3 to 4 forward-facing spines, segments 7–9 more spinous than remaining segments. Segment 5 has a single gland on external surface. Oviger segment 6 longest, about 1.1 times as long as next longest, segment 4; segment 4 has a single gland opening at about 75% of its length, segments 4–6 with scattered small, simple spines, distal four segments each bearing a dense field of long spines on the raised sole of each segment, spines spatulate, some with faint marginal serrations and obscure crenulation; terminal claw hooked, slightly skewed. Legs about 12 times length of trunk. Femur gently curved, 35–38 times as long as distal width, femur and tibia 1 subequal, tibia 1 about 22% longer than tibia 2, the tarsus is 1.7–2.3 times as long as the propodus and the claw 47–61% of the propodal length. Genital pores are on the proximal surface of a low distoventral transverse ridge on legs 3 and 4; those of some specimens about half the size of larger pores, possibly indicating sexual dimorphism. Coxal pellicula present on the dorsal surface of coxa 2 of all legs.

Distribution. A cosmopolitan deep-sea species. Regional records from Campbell Plateau, SE of Bounty Is; Lord Howe Rise and Raukkumara plain, E of North Island New Zealand. East, south and west coasts of Australia. Rarely recorded south of the Antarctic convergence. Depth, 647–5219 m.

Type locality. Eastern coast United States, (Blake stn 307, 41°29.45'N, 65°47.10'W) .

Remarks. These specimens ranged in size from 255 to 530 mm and agree in all significant respects with Wilson’s description of the holotype. In the light of this material, additional observations of intraspecific variability are noted. The distal 3 palp segments are usually recorded as being subequal, whereas in this material there are consistent but small differences. In the absence of a segmentation line separating the oviger claw from segment 10, the length of the segment is measured from the basal margin of the segment, to the distal end of the spine field and the width of the segment from the outer margin of the segment to the same point at the base of the spines. In life (specimen NMV J55743), the trunk and longer leg segments were generally a straw-colour; the proboscis, palps and ovigers a deep orange-red; the ocular tubercle, coxae and propodi of a lighter shade. The proboscis was almost blood red when the specimen was first retrieved but soon changed to match the palps and ovigers (fig. 7A). In contrast to preserved specimens with unpigmented eyes, the eyes were highly reflective, possibly luminescent. Hedgpeth’s (1948: 272) observation of the species being bright orange-scarlet in life may be a generalization or indicate intraspecific colour variation.

Figures

Figure 2. Colossendeis colossea (NMV J40745): A, dorsal view of trunk; B, palp; C, palp segments 8 to 10; D, tip, palp segment 10; E, oviger; F, oviger segments 7–10; G, oviger segment 10; H, oviger spines; I, tarsus and propodus leg 3; J, abdomen, dorsal.

Figure 7. A. Colossendeis colossea, dorsal (Photo Gowlett-Holmes, CSIRO) B. Colossendeis melancholicus. (J40746), coxal pellicula. (Photo D.A. Staples) C. Colossendeis arcuata (SAM E3383) genital pore, leg 3. D. Colossendeis arcuata (SAM E3383) sensory setae, oral surface. (Photos D.A. Staples)