Microra angulata Monniot C., 1983

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 : 191-194

Microra angulata Monniot C., 1983

( Figs. 125 , 126 )

Material examined. 3 ♀♀ (MNHN-IU-2018-1835) from Ascidiainterrupta Heller,1878 ,Riviere Sens, Guadeloupe; 2 ♀♀ (MNHN-IU-2018-1836) from A. interrupta, Grande Anse , Guadeloupe; 2 ♀♀ (both dissected and figured) from A. interrupta, Pointe de Salines , Martinique; 2 ♀♀ (MNHN-IU-2018-1920) from A. interrupta , Martinique MADIBENTHOS Stn. AR051, (14°29.6 Ń, 61°05.5 Ẃ), depth 5-25 m, 07 September 2016.

Redescription of female. Body ( Fig. 125A ) elongate and dorsoventrally depressed. Body length 1.30 mm: prosome1.02mm,occupying78%ofbodylength,consisting of cephalosome and 4 pedigerous somites. Dorsal shield of cephalosome 240×290 μm, roundedanteriorly andlaterally. Firstpedigeroussomiteveryshort, aboutone-thirdaslongas second: second to fourth 105×295, 178×309, and 436×338 μm, respectively. Fourth pedigerous somite forming brood pouch with rounded posterodorsal margin, longer than 3 anterior pedigerous somites combined. Fifth pedigerous somite completely fused with fourth. Free urosome ( Fig. 125B ) 5-segmented, graduallynarrowing posteriorly; genitalsomite 64×130 μm; 4 abdominalsomites 90×118, 80×100, 73×82, and 36×56 μm, respectively. Anal somite posteroventrally protuberant, well-sclerotized, ornamented with few spinules on ventral surface. Caudal ramus ( Fig. 125C ) small, located dorsally on anal somite, 19×19 μm, armed with 2 claws and 4 setae; 2 claws subequal, longer than ramus; one small seta inserted into basal part of dorsal claw.

Rostrum ( Fig. 125D ) triangular, directed posteriorly, not free from cephalosome. Antennule ( Fig. 125E ) small, distinctlynarrowing distally, 7-segmented; armature formula 2, 4, 9, 9, 0, 2+aesthetasc, and 10+aesthetasc; first segment inflated posteriorly; several setae pinnate; one seta on third segment spiniform, blunt, short, but broad. Antenna ( Fig. 125F ) stout, 4-segmented; coxa unarmed; basis 1.3 times longer than wide, with exopodal seta distally; first endopodal segment as long as basis, with 1 setaon inner surface; compound distal endopodal segment not elongate, slightly shorter than first, tapering, and ornamented with row of spinules; armed with 7 setae plusterminal claw longerthan segment.

Labrum missing. Mandible ( Fig. 125G ) with weakly bilobed coxal gnathobase, both lobes spinulose and without teeth; basis with 1 seta distally; exopod and endopod unsegmented, both armed with 4 setae. Maxillule ( Fig. 125H ) as tapering lobe bearing 2 subdistal and 2 larger distal setae, all setae naked. Maxilla ( Fig. 125I ) obscurely 5-segmented; first segment (syncoxa) unarmed, but with numerous spinules on outer proximal surface; secondsegment (basis) with 3 setae (1 minute, other 2 broad, spinulose distally); third and fourth segments each with 1 spinulose seta; fifth segment with 3 naked setae (1 notarticulated at base). Maxilliped ( Fig. 126A ) as small triangular lobe bearing 2 naked setae distally.

	Coxa	Basis	Exopod	Endopod
Leg 1	0-0	1-0	I-0; I-0; III, 3	0-0; 1, 2, 0
Leg 2	0-0	1-0	1-0; 1-0; 8	0-0; 2, 2, 0
Leg 3	0-0	1-0	1-0; 1-0; 7	0-0; 2, 2, 0
Leg 4	0-0	1-0	1-0; 1-0; 7	0-0; 1, 2, 1

Legs 1–4 ( Fig. 126 B-E) each with 3-segmented exopod and 2-segmented endopod. Inner coxal seta absent and outer seta on basis naked and small in all legs 1–4. Basis of leg 1 lacking inner distal element. Endopods much smaller than exopods, half as long as exopod inleg 1, 0.2 to 0.25 times as long in legs 2–4. First endopodal segment unarmed in all 4 legs, short, at most 0.3 times as long as second endopodal segment. Outer setae on second endopodal segment of legs 1–3 rudimentary. Armature formula for legs 1–4 as follows:

Leg 5 ( Fig. 125B ) represented by 2 small digitiform processes, fused at base, each bearing 1 small apical seta.

Male. Described by Monniot (1983); not found in present study.

Remarks. Some morphological aspects overlooked in the original description are emended in the above redescription. The most important emendation is the 2- segmented state of the endopods of legs 1–4. The material examined here comes from the type host A. interrupta collected in the same general locality, Guadeloupe, as the typematerial.

Figures

FIGURE 125. Microra angulata Monniot C., 1983, female. A, habitus, dorsal; B, urosome, ventral; C, anal somite and caudal rami; D, anterior part of cephalosome, ventral; E, antennule; F, antenna; G, mandible; H, maxillule; I, maxilla. Scale bars: A, B, 0.1 mm; C, E, F, 0.02 mm; D, 0.05 mm; G-I, 0.01 mm.

FIGURE 126. Microra angulata Monniot C., 1983, female. A, maxilliped; B, leg 1; C, leg 2; D, leg 3; E, leg 4. Scale bars: 0.02 mm.