Doroixys gryphina, 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 : 478

Doroixys gryphina sp. nov.

( Figs. 316 , 317 )

Typematerial. Holotype (intact ♀, MNHN-IU-2014- 21368 ) from Eudistoma reginum Kott, 1990 (MNHN-IT-2008-4187 = MNHNA3/EUD/75), CRRFOCDN 1434-S, Manado, north Sulawesi, Indonesia, depth 60 m, 21 May 1993 ; 1 paratype ♀ (dissected) from E. reginum, CRRF same locality data, Indonesia.

Etymology. The specific name is derived from the Greek gryp (=hook-nosed), referring to the hook-shaped rostrum.

Descriptionoffemale. Body ( Fig. 316A ) curved ventrally, 1.39 mm long. Dorsal cephalic shield expanded ventrolaterally; paired posterolateral horn-like processes prominent, bearing 2 nodule-like tubercles subdistally ( Fig. 316B ). Metasome unsegmented, but with 3 weak constrictions on dorsal and lateral surfaces; third and fourth pedigerous somites containing eggs and nauplii inside. Fourth pedigerous somite expanded, but shorter than anterior part of metasome. Free urosome ( Fig. 316C ) tapering posteriorly: genital and 4 abdominal somites 65×182, 45×169, 36×136, 47×122, and 64×102 μm, respectively. Anal somite and caudal rami ornamented with minute spinule-like setules on all surfaces. Caudal ramus ( Fig. 316D ) tapering distally, thin-walled in distal half, 3.0 timeslongerthan wide (96×32 μm): armedwith 6 setae; outer lateral and dorsal setae positioned at 49 and 53% of ramus length, respectively; all caudal setae shorter than width of ramus at base.

	Coxa	Basis	Exopod	Endopod
Leg 1	0-0	1-0	I-1; I-1; I+1, 1, 4	0-1; 0-1; 1, 2, 3
Leg 2	0-0	1-0	1-0; 1-0; 3, 1, 5	0-0; 0-0; 1, 2, 2
Leg 3	0-0	1-0	1-0; 1-0; 3, 1, 5	0-0; 0-0; 0, 3, 1
Leg 4	0-0	1-0	1-0; 1-0; 3, 1, 4	0-0; 0-0; 0

Rostrumlongerthanwide (120×75 μm), tapering to pointed apex in ventral view ( Fig. 316F ), hook-like inlateral view ( Fig. 316E ). Antennule ( Fig. 316G ) 157 μm long, 8-segmented; articulation incomplete between 2 distal segments; armatureformula 2, 14, 4, 3+aesthetasc, 2, 2+aesthetasc, 2, and 7+2 aesthetascs; all setae naked; aesthetascs short. Antenna ( Fig. 316H ) 4-segmented; coxa and basis unarmed; first endopodal segment with 1 small seta subdistally; compound distal endopodal segment 2.9 timeslongerthan wide (47×16 μm): armedwith 5 setae (arranged as 1, 2, and 2) plus slender terminal claw, about 0.6 times as long as segment.

Labrum lost during dissection. Mandible ( Fig. 316I ) with broadened coxal gnathobase bearing 5 teeth and 1 seta; basiswith 1 setaonmedial margin; exopodwith 5 setae (4 medial setae subequal in length and outermost seta about half as long as other 4); first endopodal segment with 1 broad seta; second endopodal segment with 4 setae (middle 2 longerthan medial and outer setae). Maxillule ( Fig. 316J ) with 9 setae on arthrite, 1 on each epipodite and basis, 4 on exopod, and 3 on endopod; 3 setaeon endopod becoming longer from medial to outer; coxal endite absent. Maxilla ( Fig. 317A ) 4-segmented; syncoxa with 4, 3, and 2 setae on first to third endites, respectively; basis with slender, smooth claw plus 1 seta; endopod with 1 and 3 setae on first and second segments, respectively. Maxilliped ( Fig. 316K ) unsegmented, taperingdistally, armed with 6 setae and ornamented with spinules along outer margin.

Legs 1–4 ( Figs. 317 B-E) with 3-segmented rami; inner seta absent on coxa. Leg 1 lacking inner distal spine on basis. All setae on legs 2–4 naked and bluntly tipped. Endopod slightly shorter than exopod in legs 2 and 3, endopod of leg 4 less than half length of exopod. Third endopodal segment of leg 4 unarmed, bearing only 2 small setules (or setal vestiges) distally. Armatureformula for legs 1–4 as follows:

Leg 5 ( Fig. 317F ) represented by 1 ventrodistal seta on surface of somite and tapering, sclerotized exopodal process lacking seta but bearing tubercle subdistally on outer margin, and ornamented with scattered setules.

Male. Unknown.

Remarks. This new species is characterised by the lack of an innerdistal element on the basis of leg 1 and by the absence of a seta on the inner (exopodal) process of leg 5. The combined setation patterns of the third endopodal segments of legs 2 to 4 (5, 4, and 0, respectively) is also an important diagnostic feature of the new species.

Figures

FIGURE 316. Doroixys gryphina sp. nov., female. A, habitus, right; B, posterolateral process of cephalic shield; C, leg 5 and urosome, ventral; D, right caudal ramus, dorsal; E, rostrum, right; F, rostrum, ventral; G, antennule; H, antenna; I, mandible; J, maxillule; K, maxilliped. Scale bars: A, 0.1 mm; B, D–F, 0.05 mm; C, 0.1 mm; G–K, 0.02 mm.

FIGURE 317. Doroixys gryphina sp. nov., female. A, maxilla; B, leg 1; C, leg 2; D, leg 3; E, leg 4; F, leg 5. Scale bars: A, F, 0.02 mm; B–E, 0.05 mm.