Doroixys, Kerschner, 1879

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 : 458-459

Doroixys -group of genera

Remarks. For convenience, the genus Doroixys Kerschner, 1879 and its allied genera are referred to here as the “ Doroixys -group”. In addition to Doroixys , the group comprises Demoixys Illg & Dudley, 1961 , Loboixys Ooishi, 2006 , and Mesoixys Illg & Dudley, 1965 plus eleven new genera. This group may be characterised by the combination of the following features: (1) female body inflated, usually globular; (2) antennule at most 9-segmented; (3) mandibular endopod armed with 1 setaon the first segment (with the exception of 2 setae in Gallincola bisetatus gen. et sp. nov.) and 4 to 7 setae on the second segment; (4) maxillule bearing at most 2 setae on the basis and lacking the coxal endite (except Prodoroixys gen. nov. which retains the coxal endite); (5) inner coxal seta usually absent from swimming legs; (6) segmentation and setation of swimming legs variously reduced; and (7) leg 5 rudimentary, lacking free exopodal segment. The important character states of the genera within the Doroixys -group are compared in Table 10 .

Species of genera in this group are mostly associated with compound ascidians, however Borixys simplex ( Marchenkov & Boxshall, 2004) comb. nov. and the speciesof Gallincola gen. nov. and Scoliosoma gen. nov. are found in association with solitary ascidians.

The fifteen genera in the Doroixys -group can be distinguished using the following dichotomous key:

1. Endopod of maxilla 3-segmented..................................... 2

Endopod of maxilla 1- or 2-segmented ............................ 3

2. Maxillule with seta-tipped coxal endite ............................. ......................................................... Prodoroixys gen. nov.

Maxillule lacking seta-tipped coxal endite......................... ............................................................... Notoixys gen. nov

3. Some setae on maxillary endopod enlarged, about twice as long as maxillary segments ................... Cystixys gen. nov.

All setae on maxillary endopod at most as long as maxillary segments ........................................................................... 4

4. Dorsalcephalic shield with 2 pairs of posterolateral horns; basis of maxillule armed with 2 setae................................. ............................................................. Diceratus gen. nov.

Dorsal cephalic shield with or without paired posterolateral horns; basis of maxillule armed with 1 seta ..................... 5

5. Caudalramus armedwith 5 setae, at least 1 longerthan ramus ............................................. Pentachaetus gen. nov.

Caudal ramus armed with 0 to 6 setae, all shorter than ramus ................................................................................ 6

6. Maxilliped absent; mandibular gnathobase styliform ........ ..................................................... Mesoixys Illg & Dudley

Maxilliped present; mandibular gnathobase otherwise .... 7

7. Mandibular gnathobase transformed to large hook ............ ........................................................... Ademoixys gen. nov.

Mandibular gnathobase with pectinate medial margin ........ ............................................................... Ctenixys gen. nov.

Mandibular gnathobase with serrate medial margin ............ .......................................................... Scoliosoma gen. nov.

Mandibular gnathobase with 3 to 6 teeth on medial margin .......................................................................................... 8

8. Leg 1 exopod 3-segmented; first and second exopodal segments each armed with outer and inner seta ............... 9

Leg 1 exopod 1- to 3-segmented; when 3-segmented, first or second segments (or both segments) lacking outer or inner seta......................................................................... 10

9. Dorsal cephalic shield with posterolateral horns; first and second exopodal segments of legs 3 and 4 lacking inner seta ..................................................... Doroixys Kerschner

Dorsal cephalic shield without posterolateral horns; first and second exopodal segments of legs 3 and 4 with inner seta ......................................................... Borixys gen. nov.

10. Exopod of mandible completely fused with basis and represented by 2 large setae.............. Ammonixys gen. nov.

Exopod of mandible defined, usually distinctly articulated from basis ....................................................................... 11

11. Urosome short, at most as long as wide; caudal rami fused with anal somite........................... Demoixys Illg & Dudley

Urosome distinctly longer than wide; caudalrami articulated from anal somite ............................................................. 12

12. Maxilliped armed with 2 or 3 setae; distalmost tooth of mandibular gnathobase elongate; gall-inhabiting in solitary ascidians ............................................ Gallincola gen. nov.

Maxilliped armed with 6 setae; distalmost tooth of mandibular gnathobase not elongate; living in compound ascidians ................................................... Loboixys Ooishi