Cystixys globosa Kim & Boxshall 2020, gen. et sp. nov.
Creators: name: Kim, Il-Hoi
name: Boxshall, Geoff A.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Copepoda
Cyclopoida
Notodelphyidae
Cystixys
Cystixys globosa

description: Cystixys globosa gen. et sp. nov.
(Fig. 348–350)
Typematerial. Holotype (intact ♀, MNHN-IU-2009- 2469), paratypes (2 intact ♀♀, MNHN-IU-2014-21394), and dissected paratypes (2 ♀♀, figured), each from membranous cyst in globular gall in Eudistoma illotum (Sluiter, 1898) (MNHN-IT-2008-XXXX = MNHNA 3 EUD 353), south of Madagascar (25°02.8 Ś, 46°59.3 É), depth 22 m, MNHN coll., 01 May 2010.
Etymology. The name alludes to the globose body of the new species.
Descriptionoffemale. Body (Fig. 348A, B) inflated, almost spherical, slightly longer than wide, 1.01 mm in greatest diameter. Cephalosome and urosome facing each other on ventral side of brood pouch. Dorsal cephalic shield (Fig.348D) withpairedhorn-likeprocesses laterally (Fig. 348D, E). Metasome unsegmented, entire metasome forming brood pouch. Free urosome (Fig. 348C) curved ventrally, stout, 5-segmented. Caudal rami (Fig. 348F) small, shorter than anal somite, about 1.6 times longer than wide (31×20 μm), setulose: armed with 6 setae, but setae difficult to distinguish from setules.
Rostrum (Fig. 348D, G) evenly tapering, longer than wide, ornamented with numerous setules. Antennule (Fig. 348H) 108 μm long, 7-segmented; second and third segments with traces of 1 and 3 sutures on posterior side, respectively, and terminal segment with trace of suture on anterior side; armature formula 2, 22, 11, 3, 2, 3, and 11+aesthetasc. Antenna (Fig. 348I) 4-segmented; proximal 3 segments stout, unarmed; terminal segment (second endopodal segment) about 3.1 times longer than wide (52×17 μm) and longer than first endopodal segment; armedwith 5 setae (arranged as 1, 2, and 2) plus small terminal claw, less than third of length of segment.
Labrum (Fig. 349A) short, unornamented, tapering towards thin, soft distal part. Mandible (Fig. 349B) with narrowcoxalgnathobasebearing1distaltoothandproximal pectinate region on medial (cutting) margin: basis with 1 medial seta; exopod with 4 large medial and 1 small outer seta (less than third length of adjacent seta): endopod with 1 and 4 setae on first and second segments, respectively; seta on first segment markedly broadened; proportional lengths of setae on second segment 7:10:17:10 from medial to outer. Maxillule (Fig. 349C) armed with 3 setae on arthrite, 1 each on epipodite and basis, 4 on exopod and 3 (1 short medial and 2 longer distal) on endopod. Maxilla (Fig. 349D) 4-segmented; syncoxawith 2 setae on each of first to third endites; basiswith 2 setae, one spiniform, spinulose; endopod small, with 1 and 3 setae on first and second segments, respectively; setaon first endopodal segment and 1 seta on second extremely large (about twice as long as entire maxilla). Maxilliped (Fig. 349E) small, unsegmented, armedwith 2 setae distally; ornamented with few setules on outer margin.
Legs 1–4 (Figs. 349F, G, 350A, B) with 3-segmented rami; coxa short or absent; intercoxal sclerite and inner coxal seta absent. Inner distal spine on basis of leg 1 large, 28 μm long. Inner setaon first endopodal segment broad. Endopods of legs 2–4 small, about half as long as exopods. Second endopodal segment of leg 2 and first and second endopodal segments of leg 3 with variable setation; setae indicated by arrowheads in Fig. 349G and 350Amay be present or absent.Armature formula for legs 1–4 as follows:
CoxaBasisExopodEndopodLeg 10-01-I1-1; 1-1; 3, 1, 30-1; 0-1; 1, 2, 2
Leg 20-01-01-1; 1-1; 3, 1, 50-0; 0-1 (or 0-2);1, 2, 3Leg 30-01-01-1; 1-1; 3, 1, 50-1 (or 0-0); 0-1(or 0-2); 1, 2, 3Leg 40-01-01-1; 1-1; 2, 1, 50-1; 0-2; 1, 2, 2
Leg 5 (Fig. 350C, D) positioned on posteroventral margin of somite and represented by outer protopodal seta and irregular inner (exopodal) process bearing 1 seta on outer margin.
Male. Unknown.
Remarks. The specimens of this species were each enclosed within a membranous cyst and each cyst was located within a gall formed in the branchial tissue of the host.
description: 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 524-527, DOI: 10.11646/megataxa.4.1.1, http://zenodo.org/record/4591138