Doropygopsis Sars, 1921

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 : 299

Genus Doropygopsis Sars, 1921

Diagnosis. Body of female comprising cephalosome, metasome of 4 well-defined pedigerous somites, and free urosome. Fourth pedigerous somite forming brood pouch, partly incorporating fifth pedigerous somite. Free urosome 5-segmented in female, 6-segmented in male. Caudalramus with 6 setae. Antennule 9-segmented in female. Antenna 4-segmented comprising coxa, basis and 2-segmented endopod; exopod absent. Mandible consistingof coxa, basis, exopod and endopod; exopod armedwith 5 setae; endopodwith 4 and 10 setaeonfirst and second segments, respectively. Maxillule armed with 10 setae on arthrite, 1 on coxal endite, 2 on epipodite, 3 on basis, and 4 on exopod; endopod 2-segmented, armed with 3 or 5 and 4 setaeon first and second segments, respectively. Maxilla with strong claw plus 2 setae on basis. Maxilliped 3-segmentedwith 9, 1 and 4 setaeon firsttothird segments, respectively. Legs 1–4 with 3- segmented rami: inner coxal seta present in leg 1, absent in legs 2–4; outer setation elements on exopods of legs 2–4 setiform. Armature formula for legs 1–4 as follows: Leg5 ( Fig.199G ) consistingof shortbroadprotopodal plate and exopod; protopodalplate with 1 outerdistalseta and row of fine spinules near base of exopod; exopodal segment about 3.6 timeslongerthan wide (59×16 μm), with narrow proximal half, armed with 1 setaat outer distal corner, and 4 rows of fine spinules distally on inner surface.

	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
Leg 3	0-1	1-0	1-1; 1-1; 2, 1, 5	0-1; 0-2; 1, 2, 3
Leg 4	0-0	1-0	1-0; 1-1; 2, 1, 5	0-0; 0-0; 1, 2, 1

Coxa Basis Exopod Endopod
Leg 1	0-1	1-I I-1; I-1; III, I, 4 0-1; 0-1; 1, 2, 3
Legs 2 & 30-0		1-0 1-1; 1-1; 3, 1, 5 0-1; 0-2; 1, 2, 3
Leg 4	0-0	1-0 1-0/1; 1-1; 2, 1, 50-0; 0-0; 1, 2, 2

Male. Unknown.

Remarks. Excluding the new species N. paucisetata gen. et sp. nov., all known speciesof Nobinerilla carry 5 setae on the third endopodal segment of leg 4 ( Table 4). The unique character state of carrying only 4 setae on this segment serves to characterise N. paucisetata gen. et sp. nov. and distinguish it from all of its congeners.

In addition, N. paucisetata gen. etsp. nov. has 6 setae on the second endopodal segment of the mandible, a feature shared only with N. alata gen. et sp. nov., N. armata , and N. minuta gen. etsp. nov. However, N. alata gen. etsp. nov. and N. minuta gen. etsp. nov. both have 9 setae on the maxilliped compared with 11 in N. paucisetata gen. et sp. nov. In addition N. armata has 3 setae on the endopod of the maxillule whereas there are 4 in N. paucisetata gen. et sp. nov. The latter species is not confusable with these three species.

Leg 5 consisting of protopod fused to somite at base, plus elongate free exopodal segment armed with 2 setae distally.

Type species: Doropygopsis longicauda ( Aurivillius, 1882) , by original monotypy.

Remarks. Sars (1921) established this genus to accommodate D. longicauda and based his decision partly on the characters of the newly discovered male, the antennules of which are described as “distinctly prehensile”, unlike those of Doropygus . The antennule of male D. longicauda is 10-segmented and geniculate (inferred from Sars’s (1921) description of the last two segments together forming a “movable terminal part admittingto beimpinged againstthe preceding part”). Two additional species have been placed in Doropygopsis , D. novemsetiferus ( Schellenberg, 1922) , redescribed below, and D. arctica Marchenkov, 1998 .

Figures

FIGURE 199. Nobinerilla paucisetata gen. et sp. nov., female. A, maxilliped; B, leg 1; C, left leg 2; D, right leg 2; E, left leg 3; F, left leg 4; G, left and right legs 5. Scale bars: A, 0.02 mm; B–G, 0.05 mm.