Notodelphyopsisfalcifera Schellenberg, 1922
(Figs. 51, 52)
Material examined. 1 ♀ (dissected and figured) from Ascidia depressiuscula Heller, 1878, Gulf of Manaar India.
Supplementary description of female. Body (Fig. 51A, B) narrow, dorsoventrally depressed and arched ventrally. Bodylength 2.43 mm. Cephalosome with angular posterolateral corners and concave posterior margin; widerthan first 3 pedigerous somites. First to third pedigerous somites broader posteriorly. Brood pouch elongatedoval, 930×590 μm, longer than preceding part of prosome, and widest in middle; fifth pedigerous somite completely fused with brood pouch. Free urosome (Fig. 51C) consisting of genital double-somite and 3- segmented abdomen: genital double-somite 114×175 μm; freeabdominalsomites 80×134, 91×127, and 80×118 μm, respectively. Caudalramus (Fig. 51C) elongate, about 12 timeslongerthan wide (500×41 μm), gradually narrowing distally; armed with 6 small setae, all setae shorter than width of ramus; proximal outer lateral seta located at 30% of ramus length.
| Coxa | Basis | Exopod | Endopod | |
|---|---|---|---|---|
| Leg 1 | 0-1 | 1-I | I-0; I-1; III, 1, 4 | 0-1; 0-1; 1, 2, 3 |
| Leg 2 | 0-0 | 1-0 | I-0: I-1; III, I, 5 | 0-1; 0-2; 1, 2, 3 |
| Leg 3 | 0-1 | 1-0 | I-0: I-1; III, I, 5 | 0-1; 0-2; 1, 2, 3 |
| Leg 4 | 0-1 | 1-0 | I-0; I-1; III, I, 5 | 0-1; 0-2; 1, 2, 2 |
Rostrum(Fig.51D)clearlydefinedfromcephalosome, spatulate, broadened in distal third, 78×86 μm. Antennule long and slender, 7-segmented, reaching to posterior margin of third pedigeroussomite when extended; seventh segment subdivided distally by indistinct suture line; armatureformula 3, 17, 6, 4, 4, 2, and 11+aesthetasc; all setae small and naked. Antenna (Fig. 51F) 3-segmented: coxa short and unarmed; allobasis slightly inflated in middle with 2 unequal, pinnate setae representing exopod on outer margin; longer seta as long as free endopodal segment, shorter seta about half as long; free endopodal segment slightly shorter and narrower than basis, 82×19 μm, armed with 8 setae plus terminal claw more than half length of segment.
Labrum hirsute distally, with straight posterior margin and small posteromedian lobe. Mandible (Fig. 51G) with 5 teeth and 2 small setae on coxal gnathobase, 2 small spinules on distal margin near base of distalmost tooth; basis with 1 seta on medial margin and scattered setules on ventral surface; exopod unsegmented with 5 setae, distal 2 setae distinctly larger (about twice length of other 3); endopod with 2 and 8 setae on first and second segments, respectively. Paragnath (Fig. 52A) as small lobe bearing rounded protuberance at outer distal corner and dense setules on medial surface. Maxillule (Fig. 51H) with 9 setae on arthrite, 1 on coxal endite, 2 on coxal epipodite, and 1 small proximal and 2 longer distalsetae onmedial margin of basis; exopod with 4 setae distally; endopod 2-segmented with 2 setae on first segment and 3 setaeon second. Maxilla (Fig. 52B) 5-segmented; with 9 enditic setae on syncoxa (arranged as 3, 1, 2, 3), 3 on basis, and 1, 1, and 3 on first to third endopodal segments. Maxilliped (Fig. 51I) 3-segmented, armedwith 9, 0, and 2 setae on first to third segments, respectively; articulation incomplete between second and third segments.
Legs 1–4 with 3-segmented rami. All legs lacking inner seta on first exopodal segment. Inner coxal seta large inleg 1 (Fig. 52C), absentin leg 2 (Fig. 52D), and small in legs 3 and 4 (Fig. 52E). Outer seta on basis large and pinnate in leg 1, but small and naked in legs 2–4. Inner distal spine on basis of leg 1 longer than first endopodal segment, 65 μm long. Exopod of leg 1 strongly curved, first segment broadened distally. Outer spines on first and second exopodal segments of legs 2–4 strong, curved outwards, claw-like. Inner setaeon exopods and endopods of legs 2–4 short and naked. Third exopodal segment of leg 4 characteristically armed with 4 spines and 5 setae as in legs 2 and 3. Armature formula for legs 1–4 as follows:
Leg 5 (Fig. 52F) represented by 2 small papillae, each tipped with 1 small seta.
Male. Not found.
Remarks. The presence of nine setal elements (III, I, 5) on the third exopodal segment of leg 4 is very unusual for notodelphyids. Even the two new basal genera Bathynotodelphys gen. nov. and Pronotodelphys gen. nov. erected in the present account (above) possess a maximum of eight elements (II, I, 5) on this segment, and this maximum is shared with Notodelphys and Paranotodelphys . The absence of an inner coxal seta on leg 2 only is also extremely unusual in copepods. When setae are lost along a leg series, the loss tends to follow an anterior to posterior, or a posterior to anterior sequence. The absence of this seta in leg 2 while it is present in legs 1, 3 and 4 requires confirmation.
The known hosts of this Indo-Pacific species include thetype host, Ascidia gemmata Sluiter, 1895 in Australia (Schellenberg, 1922), A. zara Oka, 1935 and Ciona intestinalis in Japan (Ooishi, 1962), and Phallusia nigra Savigny, 1816 in Korea (Kim, 2012). Here we add Ascidia depressiuscula from India as a new host record.