Notodelphys cuspis, Kim & Boxshall, 2020

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), Megataxa 4 (1), pp. 1-6 : 44-47

publication ID	https://doi.org/ 10.11646/megataxa.4.1.1
DOI	https://doi.org/10.5281/zenodo.5661643
persistent identifier	https://treatment.plazi.org/id/03C487CB-EF7A-3A1A-FF4D-FC9BFD6FFE8E
treatment provided by	Plazi
scientific name	Notodelphys cuspis
status	sp. nov.

Treatment

Notodelphys cuspis sp. nov.

( Figs. 26–28 View FIGURE 26 View FIGURE 27 View FIGURE 28 )

Typematerial. Holotype (intact ♀, MNHN-IU-2014- 21216 ) , allotype (intact ♂, MNHN-IU-2014-21217) , paratypes (intact, 5 ♀♀, 1 ♂, MNHN-IU-2014-21218) , and dissected paratypes (1♀, 1 ♂; figured) from Molgula occulta Kupffer, 1875 (MNHN-IT-2008-5629 = MNHN S3/ MOL.A/42), Dakar, Senegal, Stn 58-4-2B (depth 43– 44 m) & 58-2-19B (depth 12 m), IFAN coll., 1966–1969.

Etymology. Thename isderived from the Latin cuspi (= a point), referring to the tooth-like, spinous process on the inner distalcorner of the basis of leg 1.

Descriptionoffemale. Body ( Fig. 26A View FIGURE 26 ) 2.76 mm long. Prosome consisting of cephalosome and first to third free pedigerous somites, with fourth pedigerous somite forming inflated brood pouch. Fifth pedigerous somite fused to thin-walled brood pouch. Free urosome ( Fig. 26B View FIGURE 26 ) 5-segmented, consistingof genital and 4 abdominal somites: dimensions 127×233, 196×236, 211×215, 160×191, and 127×164 μm, respectively. Anal somite distinctly narrower than preceding somites. Caudal ramus ( Fig. 26C View FIGURE 26 ) about 2.9 timeslongerthan wide (145×50 μm) and 1.14 times longer than anal somite, densely setulose along outerand inner margins, armedwith 6 pinnate setae; outer lateral seta positioned at 58% of ramus length.

	Coxa Basis Exopod			Endopod
Leg 1	0-1	1-1	I-1; I-1; III, 1, 4	0-1; 0-1; 1, 2, 3
Legs 2 & 30-1	30-1	1-0	1-1; 1-1; 3, 1, 5	0-1; 0-2; 1, 2, 3
Leg 4	0-1	1-0	1-1; 1-1; 2, 1, 5	0-1; 0-2; 1, 2, 2

Rostrum ( Fig. 26D View FIGURE 26 ) 150×144 μm, tapering from broad basal region to rounded apex. Antennule ( Fig. 26E View FIGURE 26 ) 360 μm long and 15-segmented; articulation between second (III-V) and third (VI-XI) segments incomplete; armatureformula 3, 5, 12, 4, 4+aesthetasc, 2, 2, 2, 1, 2, 1, 1, 2, 2+aesthetasc, and 7+aesthetasc; 3 setae (2 on first and 1 on second segment) pinnate, all other setae naked (as figured); setaon ninth (derived from segment XX) and twelfth segments (derived from XXIII) annulated at base. Antenna ( Fig. 26F View FIGURE 26 ) 4-segmented; coxashortand unarmed; basis with 2 outer pinnate setae representing exopod (shorter seta about 65% length of longer one); first endopodal segment with 1 seta on inner margin; compound distal endopodal segment about 3.8 times as long as wide (121×32 μm), armed with terminal claw and 10 setae (arranged as 1, 1, 3, 2, and 3 from proximal to distal) and ornamented with 3 rows of spinules on outer surface; terminal claw small, about one-third length of segment; 3 distalsetae bluntly tipped.

Labrum ( Fig. 26G View FIGURE 26 ) setulose along posterior margin, with protruding posterolateral corners and convex, spinulose mid-posterior lobe. Mandible ( Fig. 26H View FIGURE 26 ) with 5 pointed teeth and 2 setae on coxal gnathobase; basis with 1 seta on medial margin; exopod unsegmented with 5 setae, distalmost seta markedly larger than others; endopod indistinctly defined from basis, armed with 4 and 9 setae on first and second segments, respectively. Paragnath ( Fig. 27I View FIGURE 27 ) lobate, with denticle apically and setules on medial margin. Maxillule ( Fig. 26J View FIGURE 26 ) armedwith 10 setae on arthrite, 1 on coxal endite, 2 on epipodite, 3 (proximal setamuch smaller than distal 2) on medial margin of basis, 4 on exopod; endopodindistinctly 2-segmented, with 1 setaon first segment and 4 on second segment; longest distal seta on second segment naked, outer seta broad proximally. Maxilla ( Fig. 27A View FIGURE 27 ) 5-segmented; syncoxa with 9 setae, grouped as 3 + minute seta, 1, 2, and 3 on first to fourth endites; basis with strong curved claw and 1 seta; endopod slender, with 1, 1, and 3 setaeonfirst to third segments, respectively. Maxilliped ( Fig. 27B View FIGURE 27 ) 3- segmented; first segment armed with 10 setae, 2 of which shorter and broader; second segment with 1 spiniform seta; third segment narrow and armed 1 large spiniform seta and 1 small naked seta.

Legs 1–4 with 3-segmented rami. Outer setaon basis short and naked in all legs ( Fig. 27C, E, F View FIGURE 27 ). Leg 1 basis broad with projecting inner distal corner tipped with denticle originating internally ( Fig. 27C, D View FIGURE 27 ) plus small, naked inner distal seta (not spine); third exopodal segment armed with 3 spines and 5 setae (terminal spine transformed to slightly curved seta); first endopodal segment as long as wide, not elongated. Legs 2–4 exopods armed only with setae; all outer setae naked. Armature formula for legs 1–4 as follows:

Leg 5 ( Fig. 27G View FIGURE 27 ) protopod fused to brood pouch, not articulated at base, with blunt outer process tipped with pinnate seta; free exopodal segment quadrate (28×28 μm) with minute, rudimentary inner subdistal seta and naked distal seta; no spinules present on protopod or exopod.

Descriptionofmale. Body ( Fig. 28A View FIGURE 28 ) narrow, 1.48 mm long. Cephalosome 316×464 μm, distinctly broader than following somites. First pedigerous somite slightly narrower than second pedigerous somite. Urosome 6- segmented, cylindrical, ventrally curved posteriorly. Anal somite ornamented with row of small spinules along posteroventral border ( Fig. 28B View FIGURE 28 ). Caudal ramus ( Fig. 28B View FIGURE 28 ) about 3.1 times longerthan wide, withsmall spinules distally and subdistally on ventral surface; setules sparse on outer and inner margins.

Rostrum as in female. Antennule ( Fig. 28C View FIGURE 28 ) 10- segmented and geniculate between eighth and ninth segments; second segment with trace of articulation proximally; armatureformula 3, 17, 2, 2, 2, 4+aesthetasc, 2, 2, 1+aesthetasc, and 10+aesthetasc; eighth and ninth segments each with fused setal element forming dentiform process on anterior margin.Antenna, mouthparts, and legs 1–4, including basis of leg 1, as in female.

Leg 5 ( Fig. 28D View FIGURE 28 ) similartothatof female. Leg 6 ( Fig. 28D View FIGURE 28 ) represented by 2 naked setae of unequal length on distal margin of genital operculum.

Remarks. This species is characterised by two unique features. The third segment of the maxilliped is armed only with 2 setae, whereas the great majority of Notodelphys species carry 3 setae on thethird segment of the maxilliped. The only exceptions are N. weberi and N. cuspis sp. nov., with the former carrying 4 setae on this segment and the latter only 2 setae. In the new species, the basis of leg 1 is armed with a small seta instead of a spine, and a small spinous process is present at the inner distal angle: such a configuration is unknown elsewhere in the genus.