Kikuchicamptus, Novikov & Sharafutdinova, 2022

Novikov, Aleksandr & Sharafutdinova, Dayana, 2022, Revision of the genus Canthocamptus (Copepoda: Harpacticoida) with a description of a new species from the Lena River Delta (North-eastern Siberia), European Journal of Taxonomy 826 (1), pp. 33-63 : 56

Kikuchicamptus gen. nov.

urn:lsid:zoobank.org:act:BF57749D-DB49-4790-B64D-8B0069B4CA3A

Table 6

Type species

Kikuchicamptus mirabilis (Sterba, 1968) comb. nov., designated here.

Other species

Kikuchicamptus coreensis ( Chang, 2002) comb. nov., K. incurvisetosus ( Chang & Ishida, 2001) comb. nov., K. morimotoi ( Miura, 1969) comb. nov., K. odaeensis ( Chang & Ishida, 2001) comb. nov., K. prominulus (Kikuchi in Kikuchi & Ishida, 1994) comb. nov., K. resupinatus (Ishida in Kikuchi & Ishida, 1994) comb. nov., K. semicirculus (Kikuchi in Kikuchi & Ishida, 1994) comb. nov. and K. tomikoae (Ishida in Kikuchi & Ishida, 1994) comb. nov.

Diagnosis

Canthocamptidae . Body semi-cylindrical. Rostrum short. Caudal rami cylindrical; setae IV and V usually long and pinnate. Female antennule 8-segmented; male antennule 10-segmented, haplocer with geniculation between segments 7 and 8. Antenna with allobasis, eXopod 2-segmented, with 4 setae. Mandible with well-developed gnathobase; palp 2-segmented. Maxilla with two endites; endopod 1-segmented. P1 with 3-segmented rami; first endopodal segment long, reaching about end of third eXopodal segment. P2–P3 with 3-segmented rami; P4 eXopod 3-segmented, endopod 2-segmented. Female P5 endopod with 6 setae, seta V approXimately equal in length to adjacent setae; eXopod long (l/w>1.7, typically 2.5–3), with 5 setae. Male P2 endopod seXually dimorphic, ʻAttheyella-likeʼ ( Fig. 11B ), second and third segment fused, third segment without outer seta and with notch on distal outer margin. Male P3 endopod typical for Canthocamptidae , with long apophysis with tip; third segment with 2 setae. Male P4 as in female. P5 endopod with 2 setae, inner seta/outer seta length from 1.3 to 1.5; eXopod with 6 setae; inner seta minute, pinnate, usually not reaching end of eXopod.

Etymology

This genus is named after Dr Yoshiaki Kikuchi, who contributed greatly to the study of Copepoda in Asia.

Remarks

Differences from similar genera, Canthocamptus and Attheyella , are presented in Table 7 . The new genus differs well from Canthocamptus in a number of characters: the shape of the male P2 endopod; longer first segment of the P1 endopod; the absence of dimorphism in the structure of the P4 endopod; the setae on the female P5 exopod and endopod of normal length; the small inner seta on the male P5 exopod. It differs from Attheyella in the 2-segmented eXopod of the antenna, in the presence of siX setae on the male P5 exopod and in the absence of setae on the arthrite of the maxillule.

Distribution

The species of the genus are distributed only in East Asia. They are recorded in Far-East Russia, China, Japan and Korea (Chang 2001, 2010).

Figures

Fig. 11. A. Quartet puzzling tree of the genus Canthocamptus Westwood, 1836, constructed by the parsimony method based on the matrix from Supp. file 1. Dots mark the main changes in character states in studied branches. Changes in the characters are marked under the dot. B. Attheyella nordenskioldii (Lilljeborg, 1902), ♂, P2 endopod. Generic abbreviations: A. = Attheyella; B. = Bryocamptus; C. = Camptocamptus; E. = Elaphoidella; H. = Heteropsyllus; K. = Kikuchicamptus gen. nov.; M. = Mesochra.