Untold diversity: the astonishing species richness of the Notodelphyidae (Copepoda: Cyclopoida), a family of symbiotic copepods associated with ascidians (Tunicata) Author Kim, Il-Hoi 0000-0002-7332-0043 Korea Institute of Coastal Ecology, Inc., 802 - ho, 302 - dong, 397 Seokcheon-ro, Ojeong-gu, Bucheon, Gyeonggi-do 14449, Republic of Korea ® ihkim @ gwnu. ac. kr; https: // orcid. org / 0000 - 0002 - 7332 - 0043 ihkim@gwnu.ac.kr Author Boxshall, Geoff A. 0000-0002-7332-0043 Korea Institute of Coastal Ecology, Inc., 802 - ho, 302 - dong, 397 Seokcheon-ro, Ojeong-gu, Bucheon, Gyeonggi-do 14449, Republic of Korea ® ihkim @ gwnu. ac. kr; https: // orcid. org / 0000 - 0002 - 7332 - 0043 ihkim@gwnu.ac.kr text Megataxa 2020 2020-12-24 4 1 1 6 http://zoobank.org/3fdd970e-62f1-4f67-8cce-10870bdb3c01 journal article 54097 10.11646/megataxa.4.1.1 7c9bc39d-9910-46f1-9558-c0647b9cbbdb 2703-3090 4591138 Chelipygus gen. nov. Diagnosis . Body of female consisting of swollen prosome and narrow, cylindrical urosome. Cephalosomewelldefinedbydorsalcephalic shield.Metasome unsegmented, strongly inflated, forming brood pouch incorporatingfifth pedigeroussomite. Freeurosome 5-segmented. Caudal ramus armed with 4 spines + 2 setae, or 3 spines + 3 setae. Rostrum present. Antennule 8- to 10-segmented. Antenna uniramous and 4-segmented, composed of coxa, basis and 2-segmented endopod. Mandible as in Doropygus ; exopod with 5 setae (distalmost seta may be vestigial); endopod with 4 setae on first segment and 8 or 9 setae on second. Maxillule armedwith 3 setae on basis, 4 setae on exopod and 2 on endopod. Maxilla lacking claw on basis; endopod 3-segmented with 3 or 4 setae on terminal segment. Maxilliped indistinctly 2-segmented, armed with 9 setae on first segment and 2 setae on second. Leg 1 with 3-segmented rami; basis with inner distal spine. Legs 2–4 each with 3-segmented exopod and 2- or 3-segmented endopod. Third exopodal segment of leg 4 armed with only 8 armature elements. Leg 5 consistingof protopod and free exopodal segment bearing 2 distal elements. FIGURE 265. Notopygus minutispinatus gen. et sp. nov. , female. A, habitus, right; B, urosome, ventral; C, left caudal ramus, dorsal; D, rostrum; E, antennule; F, antenna; G, mandible; H, paragnath; I, maxillule; J, maxilla. Scale bars: A, 0.5 mm; B, 0.2 mm; C–J, 0.05 mm. FIGURE 266. Notopygus minutispinatus gen. et sp. nov. , female. A, maxilliped; B, leg 1; C, leg 2; D, leg 4; E, leg 5. Scale bars: A, 0.05 mm; B–E, 0.1 mm. Etymology . The name of the new genus is from the Greek chel (=claw) and pygus , the ending of many taxa within the family Notodelphyidae . It refers to the presence of the spines on the caudal ramus. Gender masculine. Type species . Chelipygus bulbosus gen. et sp. nov. , by original designation. Other included species . Chelipygus dinardensis gen. etsp. nov. and C . catalai ( Illg, 1970 ) comb. nov. (originally Doropygus catalai Illg, 1970 ). Remarks . Chelipygus gen. nov . is superficially similarto Bonnierilla inhavingthebroodpouchof theadult female consisting of the entire unsegmented metasome (comprising pedigeroussomites 1 to 4). However, it differs from Bonnierilla because it is characterised by the endopod of the maxilluleusually being armed with 4 setae, the 2-segmented condition of the maxilliped which has an elongate second segment, legs 1 and 2 usually lack the inner coxal seta, the elongate exopods of the swimming legs, and the enlarged outer seta on the basis of leg 1. Chelipygus gen. nov . is similarto Notopygus gen. nov . in having an inflated prosome and spines on the caudal rami, but can be separated from the latter genus by the possession of 5 setae (or 4 setae plus a vestigial seta) on the mandibular exopod, less than 10 setae on the mandibular endopod, 4 and 2 setae on the exopod and endopod, respectively, of themaxillule (instead of 3 setae on both rami as in Notopygus gen. nov . ), no differentiated claw on the basis of the maxilla, and a total of 8 armature elements on the third exopodal segment of leg 4 (instead of 9 elements as in Notopygus gen. nov . ). Doropygus catalai Illg, 1970 wasoriginallydescribed as an associate of Ascidia sydneiensis samea (Oka, 1935) sampled in New Caledonia ( Illg, 1970 ). Kim (2012) rediscovered this species in Korea and observed that its caudal rami carry 3 spines and 3 setae, and it shares the other character states of Chelipygus gen. nov . , as listed in the generic diagnosis. It is here transferred to the new genus as Chelipygus catalai ( Illg, 1970 ) comb. nov .