Gallincola, 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 : 554-555

Gallincola gen. nov.

Diagnosis. Body curved ventrally. Prosome tapering anteriorly, unsegmented or indistinctly segmented, with swollen fourth pedigerous somite. Free urosome slender, consistingof genitalsomiteand 3-segmented abdomen. Caudal rami unarmed and with rounded distal margin. Rostrum with evenly convex distal margin. Antennule unsegmented or weakly segmented; setae small or absent. Antenna 4-segmented, with few setae only on second endopodal segment; terminal claw small. Labrum weak. Mandible with broad coxal gnathobase bearing strong, pronounced distalmost tooth; basiswith 1 seta; exopod with 5 setae; endopod 2-segmented, with 1 or 2 setaeon first segment and 5 setae on second. Maxillule with 9 setae on well-developed arthrite, 1 seta each on epipodite and basis, 4 on exopod, and 3 on endopod; coxal endite absent. Maxilla consisting of syncoxa, basis and 2-segmented endopod; syncoxa bearing 3, 1, and 2 setae on first to third endites, respectively; basis with claw plus 1 seta; endopod with total of 4 setae. Maxilliped unsegmented lobe with 2 or 3 setae. Legs 1–4 biramous with unsegmented or incompletely 2-segmented protopods; rami widely separated from each other; exopods 1- to 3-segmented; endopods muchsmaller than exopods, 1- to 3-segmented, or absentin more posterior legs. Number and size of setae on legs reduced. Leg 5 absent. Female living within discoid membranous gall on branchial tissue of host.

Type species. Gallincola bisetatus gen. et sp. nov. by original designation.

Other included species. Gallincola major gen. et sp. nov.

Etymology. The name is derived from the Latin gall (=a gall nut) and incola (an inhabitant), referring to the mode of life of the type species living inside a gall formed within the host. Gender masculine.

Remarks. We consider the genus Demoixys to be most closely related to Gallincola gen. nov. The new genus can be distinguished from the former by the form of its urosome, which is elongate (more than 3 times longerthan wide) compared with the short (at most as long as wide) urosome in Demoixys . Another difference is the pronounced distalmost tooth on the mandibular gnathobase, which is not prominent in Demoixys . In addition, the maxillular arthrite is armed with 9 setae in the new genus compared with 7 setae at most in Demoixys species, and the endopod of the maxillule is distinctly articulated from the basis, while it is fused or confluent with the basis in Demoixys .

We also note that the known hosts of the type species of Gallincola gen. nov. are solitary ascidians, whereas the known hosts of Demoixys species are compound ascidians.