Scoliosoma, Kim & Boxshall, 2020

Kim, Il-Hoi & Boxshall, Geoff A., 2020, Untold diversity: the astonishing species richness of the Notodelphyidae (Copepoda: Cyclopoida), a family of symbiotic copepods associated with ascidians (Tunicata), Megataxa 4 (1), pp. 1-6 : 558

Scoliosoma gen. nov.

Diagnosis. Female body strongly curved ventrally. Prosome divided only by constrictions. Brood pouch formed by fused swollen third and fourth pedigerous somites. Urosome rather long, apparently 6-segmented although first urosomite (fifth pedigerous somite) almost completely fused to prosome. Genital somite free. Caudal ramus small, armedwith 3 small setae. Rostrum short. Antennule broad, leaf-like, unsegmented or obscurely segmented, armed with few small setae. Antenna 4- segmented with small terminal claw. Labrum short and broad. Mandible consistingof coxa and palp; coxal gnathobase broad, bearing large, spiniform mediodistal tooth and serrate medial margin; palp consisting of basis, exopod and endopod, but rami may be fused with basis; basiswith 1 seta mediodistally; exopodwith 4 setae; endopod unsegmented with 5 setae, or 2-segmented with 1 and 4 setae on first and second segments, respectively. Maxillule comprising precoxal arthrite armed with 5 setae and lobate palp bearing 5 setae. Maxilla consisting of syncoxa, basis, and 1- or 2-segmented endopod; basis with robust claw only. Maxilliped represented by small lobe bearing 2 setae distally. Legs 1–4 rudimentary. Legs 1–3 bilobed; lobes not articulated at base and armed with minute setae. Leg 4 as small lobe. Leg 5 absent.

Type species. Scoliosoma haplomerosum gen. et sp. nov. by original designation.

Other included species. Scoliosoma dimerosum gen. etsp. nov.

Etymology. The generic name is from the Greek scoli (=curved, crooked) and soma (=body), referring the curved body of the adult female in species of the new genus. Gender neuter.

Remarks. Scoliosoma gen.nov. resembles Gallincola gen. nov.: they have a similar body form and both have a strong distal tooth on the mandibular gnathobase. Interestingly, both live in galls in solitary ascidians. However, the cephalic appendages of Scoliosoma gen. nov. are much more simplified than in Gallincola gen. nov. The mandibular exopod is armed with 5 setae in Gallincola gen. nov. but with 4 setae in Scoliosoma gen. nov. The maxillule of Gallincola gen. nov. bears as many as 9 setae on the arthrite and has a biramous palp but this appendage in Scoliosoma gen. nov. bears a total of only 5 setae on the arthrite and has a rudimentary, lobate palp. Othernotable differences include: in Scoliosoma gen. nov. the urosome is 5-segmented compared to 4-segmented in Gallincola gen. nov., the antennule is broad, leaf-like compared to elongate in Gallincola gen. nov., and the maxillary syncoxa has only 2 endites compared with 3 endites in Gallincola gen. nov.