Notoixys heardensis Kim & Boxshall 2020, gen. et sp. nov.

• Main Authors: Kim, Il-Hoi, Boxshall, Geoff A.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2020
• Subjects: Biodiversity; Taxonomy; Animalia; Chordata; Ascidiacea; Enterogona; Didemnidae; Notoixys; Notoixys heardensis; Antarctic; The Antarctic; Heard Island; Antarctic Ocean; Seta; Antarc*
• Online Access: https://zenodo.org/record/6422127; https://doi.org/10.5281/zenodo.6422127

Notoixys heardensis gen. et sp. nov. (Figs. 340, 341) Typematerial. Holotype (intact ♀, MNHN-IU-2014- 21387), paratypes (3 intact ♀♀, MNHN-IU-2014-21388), and dissected paratypes (2 ♀♀, figured) from branchial chamber of Aplidiumacropodium Monniot F. & Gaill, 1978 (MNHN-IT-2008-155 = MNHNA 1/ APL.B/111), Heard Island, Antarctic Ocean, ”Marion Dufresne”, 52°59.4’S, 73°38’E, depth 90 m, 08 April 1974, MNHN coll. Etymology. The new species is named after the type locality, Heard Island in the Antarctic. Descriptionoffemale. Body (Fig. 340A) swollen, 1.80 mmlong. Prosome 1.72 mmlong; dorsalcephalic shield expanded ventrolaterally, well-defined from metasome, bearing paired, tapering horn-like processes (Fig. 340D) posterolaterally. Metasome globular, unsegmented, with thin exoskeleton; fifth pedigerous somite completely fused with fourth. Freeurosome (Fig. 340B) stout, tapering, 5-segmented. Anal somite and caudal rami setulose. Caudal ramus (Fig. 340C) about 1.7 times longerthan wide (74×44 μm), withrounded distal margin; caudal setae not discernible from setules. Rostrum (Fig. 340E) large, elongate, twice as long as wide, constricted at proximal 20%, widest at proximal third, tapering in distal two-thirds towards blunt apex; surface ornamented with setules. Antennule (Fig. 340F) indistinctly 10-segmented; proximal 2 segments much broader than following segments; terminal segment subdivided by indistinct articulation on one surface; firstandsecondsegments armedwith 3 and 17 setae, respectively; armature uncertain for remaining segments. Antenna (Fig. 340G) 4-segmented, with 2-segmented endopod; coxa, basis, and first endopodal segment unarmed; compound distal endopodal segment about 2.8 timeslongerthan wide (47×17 μm): armed with 9 small setae (arranged as 1, 1, 2, 2, and 3) plus slender terminal claw, half as long as segment. Labrum not examined. Mandible (Fig. 340H) with narrow medial margin on coxal gnathobase, bearing 7 teeth of irregular sizes: basis with large medial seta: exopod with 5 setae, outer ...