Vivgottoia garwoodi, Kim & Sikorski & O’Reilly & Boxshall, 2013

Kim, Il-Hoi, Sikorski, Andrey, O’Reilly, Myles & Boxshall, Geoff A., 2013, Copepods associated with polychaete worms in European seas, Zootaxa 3651 (1), pp. 1-62 : 43-44

Vivgottoia garwoodi n. gen. et n. sp.

Type material: Holotype ♀ ovigerous (dissected and mounted on a glass slide) from inside tail fragment of terebellid polychaete (probably Phisidia aurea ); Glen Arm , Antrim, Northern Ireland, Stn GL 5C (54 o 58.20’N, 05 o 55.32’W), depth 32 m, collected by P. Garwood; BMNH Reg. No. 2012.1394.

Female. Body ( Fig. 23A ) vermiform, elongate, cylindrical, and composed of well-marked cephalosome, first to fifth pedigerous somites, genital complex and 1-segmented abdomen. Body length 2.04 mm. Cephalosome smaller than pedigerous somites, 141×166 µm, nearly circular, with slightly produced but truncate frontal margin. First to fifth pedigerous somites distinctly defined from one another by lateral constrictions, 166×178, 295×233, 350×233, 430×255, and 313×231 µm, respectively. Genital complex 81×179 µm; paired genital apertures large and each positioned dorsolaterally on enlarged genital prominence ( Fig. 23B ). Abdomen 1-segmented, dorsally confluent with but ventrally well defined from genital complex, about 246×91 µm. Caudal ramus tapering, fused to abdomen at base, about 144×44 µm, with 2 lateral and 2 small distal setae.

Rostrum ( Fig. 23C ) shield-like, directed posteroventrally, longer than wide and truncate at apex, ornamented with 2 pairs of setules on anterior surface. Antennule ( Fig. 23D ) stout and 5-segmented; first segment longest; armature formula 1, 2, 1, 1, and 1; distal 2 segments with minute spinules along anterior margin. Antenna ( Fig. 23E ) 2-segmented; proximal segment 2.5 times as long as wide, unarmed but with patch of spinules distally; distal segment twice as long as wide, inserted on outer margin of proximal segment, armed with 3 apical setae, one distinctly larger than other 2.

Labrum ( Fig. 23G ) unornamented, with strongly tapering posterior margin. Mandible ( Fig. 23H ) terminating in single blade, articulated at base. Maxillule ( Fig. 23I ) lobate, armed with 2 outer and 2 medial setae. Maxilla ( Fig. 23J ) 2-segmented; proximal segment unarmed; distal segment forming strong claw bearing subdistal patch of spinules on convex margin. Maxilliped ( Fig. 23K ) 3-segmented; first segment expanded but unarmed; second segment small and unarmed; terminal segment forming strong, smooth claw.

Legs 1–4 ( Fig. 24A–D ) positioned ventrolaterally, all identical in form, biramous, composed of undivided protopod and single-segmented rami; intercoxal sclerites lacking; each protopod with 1 outer seta but lacking inner seta; both rami of legs indistinctly defined from protopod. Exopod of all legs with longitudinal sclerotization along outer margin and bearing either 1 (in legs 1, 3 and 4) or 2 (in leg 2) simple setae. Endopod of all legs expanded, foliaceous and unarmed, with constriction on outer margin and sclerotization along outer margin of distal part.

Leg 5 ( Fig. 24E ) rudimentary, represented by 2 simple setae. Leg 6 absent.

Male. Unknown.

Etymology. The specific name honours Dr Peter R. Garwood (Identichaet, Newcastle-upon-Tyne) in recognition of his contributions over many years collecting copepods associated with invertebrates.

Remarks. This is the first clausiid to be reported from a terebellid host, although terebellids are common hosts of symbiotic copepods from other families such as the Saccopsidae and Xenocoelomatidae .

Figures

FIGURE 23. Vivgottoia garwoodi n. gen. et n. sp., holotype female. A, habitus, dorsal; B, urosome, dorsal; C, rostrum, anteroventral; D, antennule; E, antenna; F, antennae and mouthparts, ventral; G, labrum, ventral; H, mandible; I, maxillule; J, maxilla; K, maxilliped. Scale bars: A, 0.2 mm; B, 0.1 mm; C, D, F, J, K, 0.02 mm; E, G–I, 0.01 mm.

FIGURE 24. Vivgottoia garwoodi n. gen. et n. sp., holotype female. A, leg 1; B, leg 2; C, leg 3; D, leg 4; E, leg 5. Scale bars: A–E, 0.02 mm.