Nobinerilla alata, 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 : 279

Nobinerilla alata gen. et sp. nov.

( Figs. 186 , 187 )

Typematerial. Holotype (intact ♀, MNHN-IU-2014- 21293 ) , paratypes (2 intact ♀♀, MNHN-IU-2014-21294), anddissectedparatype (♀, figured) from Pycnoclavella flava (Monniot F., 1988) Chenal du Îlot Canard , New Caledonia, NC 41, depth 22 m, 17 March 1987.

Etymology. From the Latin alat (=winged), referring to the presence of epimeral wings on the metasome.

Descriptionoffemale. Body ( Fig. 186A ) small, compressed; length about 1.20 mm. Cephalosome welldefined. Metasomeunsegmented with 2 pairs of large wings (epimera) near bases of legs 2 and 3: wings incurved and separated from surface of metasome, forming attenuated posterodistal process withshort membrane along dorsal margin. Fifth pedigerous somite fused with metasome. Freeurosome ( Fig. 186B ) 5-segmented: genital somite short but distinctly wider than abdomen; 4 abdominalsomites 53×115, 40×106, 40×102, and 49×90 μm, respectively. Caudalramus ( Fig. 186E ) about 2.1 timeslongerthan wide (79×37 μm) and about 1.2 times longerthan anal somite, gradually narrowing distally: armed with 6 naked setae; outer lateral and dorsal setae located at 55 and 76% of ramus length; longest distal seta about 1.3 times longer than ramus, second longest seta nearly as long as ramus.

Coxa	Basis	Exopod	Endopod
Leg 1 0-0	1-I	I-1; I-1; III, I, 4	0-1; 0-1; 1, 2, 2
Leg 2 0-0	1-0	1-1; 1-1; 3, 1, 5	0-1; 0-2; 1, 2, 3
Left leg 3 0-1	1-0	1-1; 1-1; 2, 1, 5	0-1; 0-2; 1, 2, 3
Right leg 3 0-1	1-0	1-1; 1-1; 1, 1, 5	0-1; 0-2; 1, 2, 3
Left leg 4 0-0	1-0	1-0; 1-0; 2, 1, 4	0-0; 0-0; 1, 2, 2
Right leg 4 0-0	1-0	1-0; 1-1; 2, 1, 5	0-0; 0-1; 1, 2, 2

Rostrum ( Fig.186C ) shortand wide, stronglytapering towardsobtuse apex.Antennule ( Fig.186D ) ratherslender, 9-segmented; first and second segments not strongly expanded; eighth segment subdivided by incomplete suture line; armatureformula 3, 15, 6, 3+aesthetasc, 1, 3, 2+aesthetasc, 4+aesthetasc, and 7+aesthetasc; all setae naked. Antenna ( Fig. 186F ) stout, 4-segmented; coxa and basis unarmed; first endopodal segment with small seta on inner margin; compound distal endopodal segment 40×21 μm, as long as first segment: armed with 8 setae plus large, stongly curved terminal claw, longer than segment.

Labrum very weak and destroyed during dissection. Mandible ( Fig. 186G ) with 5 teeth on coxal gnathobase; basis with very small medial seta; exopod with 5 setae, distal outer seta shorter than other 4; endopod indistinctly articulated from basis, with 4 and 6 setae on first and second segments, respectively; outer distal seta on second endopodal segment shorter than other 5 setae. Paragnath ( Fig. 186H ) with short, blunt process apically and setules onmedial margin. Maxillule ( Fig. 186I ) with 9 setaeon arthrite, 1 on coxal endite, 2 on epipodite, 3 on basis and 4 each on exopod and endopod. Maxilla ( Fig. 186J ) with 9 setae (grouped as 3, 1, 2,and 3) on syncoxa, clawplus 1 seta on basis, and 1, 1, and 2 setae on first to third endopodal segments, respectively. Maxilliped unsegmented ( Fig. 187A ), lacking distal prolongation; armedwith 8 (4+4) setae medially and 1 outer distal seta.

Legs 1–4 ( Fig. 187 B-F) with 3-segmented rami. Inner coxal seta present in leg 3, but absent in legs 1, 2 and 4. Outer setaon basis large (longer than exopod in leg 1), small in legs 2–4. Inner distal spine on basis of leg 1 extending to distal border of first endopodal segment, 28 μm long. Exopods of legs 2–4 bearing only setae. Legs 2–4 asymmetrical: setae on endopods long on left legs, but those of right legs short and blunt at tip (cf. Fig. 187E and 187F ). Exopod slightly longer than endopod in leg 1, and about 1.5 times longer in legs 2–4. Legs 3 and 4 with different armature formula between left and right legs. Armature formula for legs 1–4 as follows:

Leg 5 ( Fig. 187G ) consisting of short but broad protopodalplate (formed byfusedleft and right protopods) and free exopodal segments; protopodal plate with 1 seta at each outer distal corner and row of minute spinules near base of exopod; free exopodal segment small, about 3.5 times longerthan wide (38×11 μm), lacking ornamentation, armed with 1 seta at outer distalcorner.

Male. Unknown.

Remarks. The distinctive wing-like projections on the metasome have not been recorded previously in related genera.

Figures

FIGURE 186. Nobinerilla alata gen. et sp. nov., female. A, habitus, right; B, urosome, ventral; C, rostrum; D, antennule; E, caudal ramus; F, antenna; G, mandible; H, paragnath; I, maxillule; J, maxilla. Scale bars: A, 0.1 mm; B, E, G, 0.05 mm; C, D, F, H–J, 0.02 mm.

FIGURE 187. Nobinerilla alata gen. et sp. nov., female. A, maxilliped; B, leg 1; C, left leg 2; C, left leg 3; E, left leg 4; F, right leg 4; G, leg 5. Scale bars: A, G, 0.02 mm; B–F, 0.05 mm.