Remex Monniot C., 1983

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 : 454

Genus Remex Monniot C., 1983

Diagnosis. Body of female slightly depressed: consisting of cephalosome, short neck, expanded brood pouch and narrow urosome. Brood pouch formed by fused fourth and fifthpedigerous somites. Freeurosome 5-segmented but with traces of articulations. Caudal rami whip-like. Rostrum shield-like. Antennule 7-segmented. Female antenna 3-segmented, comprising coxa, allobasis and unsegmented free endopod bearing terminal claw. Male antenna forming powerful chelate grasping organ. Mandible with coxal gnathobase forming broad cutting margin; basis separate; endopod 2-segmented, separate from basis; first and second endopodal segments with 3 and 7 setae, respectively; exopod 1-segmented, armed with 5 setae. Maxillule armedwith 8 setaeon arthrite, 1 on endite and 1 on epipodite, 3 on basis, 4 on exopod and 5 on endopod. Maxilla 3-segmented; basis with claw plus 2 setae; endopod small, 1-segmented with 4 setae plus spiniform process. Maxilliped 2-segmented, armedwith 5 setae on first segment and 3 setae on second. Legs 1–4 with 3-segmented exopods and 2-segmented endopods; inner coxal seta absent in all legs; basis of leg 1 with inner distal spine. Leg 4 lacking inner seta on first exopodal segment. Armature formula for legs 1–4 as follows.

Leg 5 comprising lateral papilla bearing protopodal seta and exopodal segment armed with 2 setae distally.

Type species. Remex obesus Monniot C., 1983 , by original designation.

Remarks. When he established Remex, Monniot (1983) considered that it was related to Lonchidiopsis . These two genera appear to form a distinct group and may be distinguished from other related genera by shared features, such as: (1) antenna sexually dimorphic, cheliform in male; (2) basis and first endopodal segment of mandible fused; (3) endopod of maxillule armedwith 5 setae; (4) maxilla with strong claw on basis and atrophied endopod; (5) maxilliped bipartite, armedwith 3 setae on distal part (or segment); (6) legs 1–3 each with 2- segmented endopod; and (7) leg 5 rudimentary. Of these, three features, the sexually dimorphic antenna, the 5 setae on the maxillulary endopod, and the bipartite maxilliped with 3 distal setae, are unusual and serve to characterise the group. Remex is not confusable with Lonchidiopsis , however, because it has 3-segmented exopods in legs 1–3, and displays a peculiar form of the caudal rami and leg 4.