Procampodelphys unipedatus, 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 : 586-588

Procampodelphys unipedatus gen. et sp. nov.

( Fig. 395 )

Type material. Holotype ♀ (dissected and mounted on a slide, MNHN-IU-2014-21384 ) from Lissoclinum bilobatum Millar, 1955 (MNHN-IT-2008-4921 = MNHN A2/LIS/153), Port Elizabeth, South Africa, intertidal, Monniot coll., 01 February 1996.

Etymology. The specific name is derived from the Latin uni (=one) and pedat (=having feet), and refers to the presence of only one pair of legs.

Descriptionoffemale. Body ( Fig. 395A ) caterpillarlike, strongly curved ventrally, surface densely covered with fine setules: consistingof unsegmented prosome and small free urosome. Body length 2.45 mm; greatest width of prosome 545 μm across posterior part. Cephalosome ( Fig. 395B ) as long as wide, defined from metasomal region by weak constriction. Rostral region produced anteriorly. Freeurosome ( Fig. 395C ) short, 160 μmlong, consistingof genitalsomiteand 2 abdominal somites. Genital somite bearing copulatory pore on ventral surface. Caudal rami ( Fig. 395C ) fused with anal somite, as long as wide, ornamented with setules mainly distally; armed with 1 small, bifurcate seta distally.

Rostrum as prominence on frontal margin of cephalosome ( Fig. 395B ). Antennule ( Fig. 395D ) attenuated, about 120 μm long, unsegmented with several partial suture line along posterior side; densely covered with setules, setae small, similar in form to setules. Antenna ( Fig. 395E ) slender, 3-segmented; coxa and basis unarmed; unsegmented endopod 2.9 times longer than wide (58×20 μm); armed with 4 small setae (1 on proximal inner margin, 1 subdistal, and 2 distal) plus very small terminal claw, about 20% length of endopod.

Labrum ( Fig. 395F ) shortand broad, withrounded, setulose posterior margin. Mandible ( Fig. 395G ) consisting of coxa with extended gnathobase bearing pectinate medial margin and markedly convex distal margin, and biramous palp armed with 4 setae on exopod and 1 seta on basis; endopod only partially demarcated from basis, with 2 setae on first segment and 3 setae on second. Maxillule (( Fig. 395H ) consisting of precoxa and unsegmented, lobate palp; with 3 setaeon medial margin of precoxal arthrite and 6 setae on palp; all setae broad and pinnate. Maxilla ( Fig. 395I ) 2-segmented; first segment with 2 setae; second segment subdivided by partial suture line, armed with 2 smaller medial and 2 larger distal setae; all setae pinnate. Maxilliped ( Fig. 395J ) lobate, bearing 5 subequal, naked setae distally.

Leg 1 ( Fig. 395K ) densely covered with setules, obscurely 2-segmented; first segment (protopod) with outerdistalseta; secondsegment bilobed, with 2 setae distally on longer outer lobe (exopod) and 1 seta distally on shorter inner lobe. Legs 2–5 absent.

Male. Unknown.

Remarks. The new species is distinguishable from its four congeneric species by its 2-segmented maxilla (3-segmented in congeners), by the possession of 5 setae on the maxilliped (6 or 7 setae in congeners), and by the absence of legs 2–4 (legs 2 and 3, at least, are present in congeners).

Figures

FIGURE 395. Procampodelphys unipedatus gen. et sp. nov., female. A, habitus, right; B, cephalosome, dorsal; C, urosome, ventral; D, antennule; E, antenna; F, labrum; G, mandible; H, maxillule; I, maxilla; J, maxilliped; K, leg 1. Scale bars: A, 0.2 mm; B, 0.1 mm; C, 0.05 mm; D–I, K, 0.02 mm; J, 0.01 mm.