Prodoroixys antarctica Kim & Boxshall 2020, gen. et sp. nov.

• Main Authors: Kim, Il-Hoi, Boxshall, Geoff A.
• Format: Text
• Language: unknown
• Published: Zenodo 2020
• Subjects: Biodiversity; Taxonomy; Animalia; Chordata; Ascidiacea; Enterogona; Didemnidae; Prodoroixys; Prodoroixys antarctica; Antarctic; The Antarctic; Kerguelen; Kerguelen Islands; Seta; Antarc*; Antarctica; Copepods
• Online Access: https://dx.doi.org/10.5281/zenodo.5699914; https://zenodo.org/record/5699914

Prodoroixys antarctica gen. et sp. nov. (Figs. 336, 337) Typematerial . Holotype (intact ♀, MNHN-IU-2014- 21384), paratypes (5 intact ♀♀, MNHN-IU-2014-21385), and dissected paratypes (2 ♀♀, figured) from Synoicum salivum Monniot F. & Gaill, 1978 (MNHN-IT-2008-8621 = MNHNA 1/ SYN /28), Kerguelen Islands, MD 04 DR106 (49°00’18″S, 67°30’42’’E), “Marion Dufresne”, depth 206 m, Boury-Esnault coll., 01 March 1975. Additional material . 13 ♀♀ (MNHN-IU-2018- 1906) and 1 dissected ♀ from Synoicum sp., Kerguelen Islands, MD 04 DR 106; 17 ♀♀ (MNHN-IU-2018- 1907) from Aplidium sp., Kerguelen Islands, MD 03 Pr 61; 14 ♀♀ (MNHN-IU-2018-1908) from Synoicum sp., Kerguelen Islands. MD 04 DR 106. Etymology . The specific name of the new species refers to its distribution in the Antarctic. Descriptionoffemale . Body (Fig. 336A) similarto typical Doroixys , 1.09 mmlong. Prosome 0.89 mmlong, relatively narrow; dorsal cephalicshielddistinctly defined, with acutely pointed posterolateral horn-like process on each side. Metasome unsegmented, distinctly longerthan wide, graduallybroadeningposteriorly; fifthpedigerous somite completely fused with fourth. Freeurosome (Fig. 336B) 5-segmented: genital somite distinctly longer and wider than abdominal somites. Surface of abdominal somites densely ornamented with setules. Caudal ramus (Fig. 336C) about 2.3 timeslongerthan wide (68×30 μm) and as long as anal somite; ornamented with numerous setules: armed with 6 setae, 2 proximal setae positioned at 46% and 60% of ramus length; 4 distal setae blunt at tip; all caudal setae shorter than ramus width. [table omitted] Rostrum (Fig. 336D) 100×74 μm, tapering, setulose distally, slightly constricted at proximal third; apex rounded. Antennule (Fig. 336E) 154 μm long, 9- segmented; third segment with traces of 2 articulations; armatureformula 2, 17, 5, 3+aesthetasc, 3, 2+aesthetasc, 2, 2+aesthetasc, and 7+aesthetasc; setae crowded, all naked. Antenna (Fig. 336F) 4-segmented; proximal 3 segments shortand unarmed, terminal (secondendopodal) segment longest, 2.5 times longerthan wide (45×18 μm); armed with 10 setae (arranged as 1, 1, 3, 2, and 3) plusterminal claw less than half length of segment. Labrum (Fig. 336G) with denselysetulose posterior marginand posteromedial lobe. Mandible (Fig. 336I) with 6 acute teeth and 2 small setae on coxal gnathobase: basiswith 1 seta medially: exopodwith 5 setae, shortest outer seta about 0.6 times as long as adjacent distal seta: endopod 2-segmented; first segment with 1 seta; second segment with 6 or 7 setae, third medial seta (indicated by arrowhead in Fig. 336I) present or absent. Paragnath (Fig. 336H) lobate, bearing small tooth apically and setules on medial surface. Maxillule (Fig. 336J) armedwith 9 or 10 setae on arthrite (small seta indicated by arrowhead present or absent), 1 each on coxal endite and epipodite, 2 on basis, 4 on exopod and 3 on endopod; setae on exopod and endopod subequal in length. Maxilla (Fig. 337A) 5- segmented; syncoxa with 3, 1, 2, and 3 setae on first to fourth endites, respectively; basis with slender claw plus 2 unequal setae; endopod with 1, 1, and 3 setae on first to third segments, respectively. Maxilliped (Fig. 337B, C) unsegmented elongate lobe, bearing 6 to 9 setae (3 to 6 medial and 2 or 3 apical). Legs 1–3 (Fig. 337 D-F) with 3-segmented rami. Leg 4 (Fig. 337G) with 3-segmented exopod and 2-segmented endopod. Endopods shorter than exopods; endopods of legs 3 and 4 small, less than half length of exopod. Inner coxal seta present only on leg 1. Inner distal spine on basis of leg 1 bilaterally serrate, 20 μm long. All setae on rami of legs 2–4 bluntly tipped. First and second exopodal segments of legs 3 and 4 lacking inner seta. Second endopodal segment of leg 3 and first endopodal segment of leg 4 lacking inner seta. Number of inner setae on second endopodal segment of leg 2 variable, 1 or 2 (usually 1, indicated by arrowhead in Fig. 337E). Number of setae on second endopodalsegment of leg 4 (Fig. 337G, H) also variable, 2 to 4 (usually 3). Armature formula for legs 1–4 as follows: Leg 5 (Fig. 336B) located posteroventrally on somite and represented by outer protopodal papilla tipped with 1 seta and inner exopodal lobe tipped with 1 seta and 1 minute setule. Male . Unknown. Remarks . The armature of the second endopodal segment of the mandible, the arthrite of the maxillule, the maxilliped, and the endopods of legs 2 and 4 of the new species are variable, and are not robust taxonomic characters. : Published as part of 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), pp. 1-6 in Megataxa 4 (1) on pages 507-510, DOI: 10.11646/megataxa.4.1.1, http://zenodo.org/record/4591138