Caligus hemiconiati Capart, 1941

Boxshall, Geoffrey A. & Bernot, James P., 2023, Resolving taxonomic and nomenclatural problems in the genus Caligus O. F. Müller, 1785 (Copepoda: Caligidae), Zootaxa 5360 (4), pp. 545-567 : 549

Caligus hemiconiati Capart, 1941

Material examined by R. F. Cressey: Syntype female from Ephippion guttifer (Bennett, 1831) (as Hemiconiatus guttifer ) caught off the coast of Gambia during the Ninth cruise of the “Mercator”, loaned to R. F. Cressey by the Museé royal d’Histoire naturelle, Brussels (Reg. No. I.G. 10910).

Supplementary Description: Abdomen broad, tapering slightly towards posterior margin; caudal rami located at small distance medial to posterolateral corners of abdomen. Caudal rami ( Fig. 3A ) wider than long and armed with 6 setae as typical for genus. Antenna ( Fig. 3B ) with small, pointed process on posterior margin of proximal segment, and armed with short seta proximally on subchela. Postantennal process ( Fig. 3B ) strongly curved and ornamented with multisensillate papillae. Maxillule ( Fig. 3B ) with curved, tapering posterior process. Sternal furca ( Fig. 3C ) with slender, strongly tapering tines; slightly asymmetrical with one tine straight and other slightly incurved. Second endopodal segment of leg 2 ( Fig. 3D ) short, broad, and with outer margin ornamented with setules; outer spine on first exopodal segment large and aligned obliquely across surface of ramus, spine on second segment similarly aligned; third exopodal segment with II, I, 5 setal formula. Leg 3 exopod ( Fig. 3E ) with first segment lacking inner seta, bearing long, slightly curved, outer spine reaching beyond articulation separating second and third segments. Leg 4 ( Fig. 3F ) comprising protopodal segment and 2-segmented exopod: first exopodal segment armed with long, tapering outer spine reaching almost to tip of ramus; second exopodal segment bearing 3 distal margin spines decreasing in length from inner to outer.

Remarks: The original description was generic and provided few specific details but there were sufficient differences to enable Capart (1941) to distinguish between his new species and C. balistae Steenstrup & Lütken, 1861 , which shares a similar leg 4. Caligus hemiconiati differs from C. balistae in numerous characters, in particular the shape of the abdomen and caudal rami. The abdomen is widest posteriorly in C. balistae and the caudal rami are located on the posterior margin directly at the posterolateral angles of the abdomen ( Cressey, 1991: Fig. 31) whereas in C. hemiconiati the abdomen is broadest more anteriorly and the caudal rami are positioned some distance medial to the posterolateral angles of the abdomen. In addition, the caudal rami are about as long as wide in the former species, compared to distinctly wider than long in the latter.

Figures

FIGURE 3. Caligus hemiconiati Capart, 1941 adult female (body length 3.2 mm). A, distal part of abdomen and caudal rami, dorsal; B, antenna, postantennal process and maxillule in situ, ventral; C, sternal furca; D, rami of leg 2 (with some setae missing on endopod); E, exopod of leg 3; F, exopod of leg 4.