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 Paranotodelphys scutiformis Schellenberg, 1922 ( Figs. 31 , 32 ) Material examined . 1 ♀ (dissected) from Phallusia obesa , Vanuatu , Stn 581, Debitus coll., 1996. Supplementary description of female . Body ( Fig. 31A ) dorsoventrally depressed, 2.09 mm long, with relatively large prosome and small urosome. Prosome withparallellateral margins.Cephalosome short, 385×618 μm, with concave posterodorsal margin. First pedigerous somiteshort, lacking epimera.Secondandthirdpedigerous somites with well-developed epimera, 138×618 and 153×611 μm, respectively. Fourthpedigerous somite forming brood pouch incorporating fifth pedigerous somite, about 1.9 times as long as wide (1171×611 μm), with rounded posterior margin. Free urosome ( Fig. 31B ) 5-segmented; somites much wider than long, 42×141, 53×124, 47×108, 44×92, and 45×82 μm, respectively. Anal somite telescoped into third abdominal somite in observed specimen; anal operculum well-developed, extending beyond posterior margin of somite ( Fig. 31C ). Caudal ramus ( Fig. 31C ) short, about 1.3 times longer than wide (45×34 μm), armedwith 6 setae (setae II and III omitted in Fig. 31C ) and ornamented with 2 dorsal setules and short, tapering tube pore (indicated by arrowhead). FIGURE 29. Paranotodelphys saccata Stock, 1967 , female. A, habitus, right; B, urosome, ventral; C, left caudal ramus, ventral; D, rostrum; E, antennule; F, antenna; G, maxillule; H, maxilliped. Scale bars: A, 0.5 mm; B, 0.1 mm; C–F, 0.05 mm; G, H, 0.02 mm. FIGURE 30. Schematic comparison of antennular segmentation patterns in selected notodelphyid taxa. Roman numerals mark ancestral segments, Arabic numerals indicate number of setae on each segment/compound segment. ae = aesthetasc. Supernumerary setae are identified by reference to the observed maximum setal number known within the Copepoda (see Boxshall & Huys, 1998 ). Supernumerary setae are present on segments III–XI, XII–XIV, XV–XVI, XXIV and XXV of Paranotodelphys polycarpae , on segments III–XI, XII, XV–XVI, XXI–XXIII, XXIV, XXV and XXVI–XXVIII of P. saccata , and on segments XVII–XX, XXI–XXIII, XXIV, and XXV of Doropygopsis novemsetifera . * The total setal counts on these segments of Doropygopsis novemsetifera probably include a setiform aesthetasc. Rostrum ( Fig. 31D ) directed posteriorly, tapering towards blunt apex. Large triangular tubercle present posterior to rostrum ( Fig. 31D ). Antennule slender; segmentation and setation not observed due to damage. Antenna ( Fig. 31E ) slender: coxa obscure; basiswith 2 large pinnate exopodal setae of equal length; endopod 2-segmented; first segment with 1 inner seta; compound distal segment elongate, about 5 times longer than wide, and armed with 10 setae plus terminal claw about onethirdaslongas segment. Labrum ( Fig. 31F ) with straight posterior margin bearing setules. Mandible ( Fig. 31G ) consistingof coxa and palp: coxa with 4 teeth and 1 setaon gnathobase: palp consistingof basis, exopod and endopod; basis with setules on outer and medial margins and armed with 1 setaonmedial margin; exopodwith 5 setae, distalmost markedly larger than other 4; endopod 2-segmented and armed with 2 and 7 setae on first and second segments, respectively; suture line obscure between basis and first endopodal segment. Maxillule ( Fig. 31H ) with 10 setae on arthrite, 1 on coxal endite, 2 on epipodite, 3 onmedial margin of basis (2 small proximal and 1 larger distal), 4 on small exopod, and 5 on incompletely 2-segmented endopod (2 on first and 3 on second segment). Maxilliped ( Fig. 31J ) with 9, 0, and 2 setae on first to third segments; second segment with prominent bulbous swelling distally; third segment small, tapering, 1 seta fused with segment, lacking articulation at base. Leg 1–4 with 3-segmented rami; coxa narrow; basis obliquely elongated. Inner coxal seta pinnate in leg 1 ( Fig. 32A ) and leg 3, but naked in leg 2 ( Fig. 32B ) and leg 4. Outer seta on basis small and naked in legs 1 and 4 but pinnate in legs 2 and 3. Armature formula as in generic diagnosis although third exopodal segment of leg 4 not observed due to damage. Leg 5 ( Figs. 31B , 32C ) represented by 2 knobs on posterior margin of brood pouch, each tipped by naked seta, inner (exopodal) knob articulated at base. Male . Not found. Remarks . This is the type species of the genus ( Illg, 1958 ). This single female from Vanuatu is tentatively identified as P. scutiformis on the basis of the following shared characteristics: the prosome of the female has parallel lateral margins and the caudal ramus is short, only slightly longer than wide (1.25 times longer than wide, according to Schellenberg, 1922 ) and as long as anal somite.