Caligus pagri 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 : 553-555

Caligus pagri Capart, 1941

Material examined by R. F. Cressey: Syntype female from Evynnis ehrenbergi (Valenciennes, 1830) (as Pagrus ehrenbergi ) caught off the coast of Gambia, loaned to R. F. Cressey by the Museé royal d’Histoire naturelle, Brussels (Reg. No. I.G. 10910).

Supplementary Description: Abdomen of female indistinctly 2-segmented ( Fig. 6A ) with somites separated by shallow groove. Caudal rami ( Fig. 6B ) about 1.5 times longer than wide and ornamented with long setules on medial margin. Antenna ( Fig. 6C ) lacking posterior process on proximal segment; subchela armed with 2 minute setal vestiges. Postantennal process ( Fig.6C ) with small slightly curved tine, shorter than base. Maxillule ( Fig. 6C ) with tapering posterior process. Sternal furca ( Fig. 6D ) with blunt, weakly diverging tines. Second exopodal segment of leg 1 ( Fig. 6E ) with 3 plumose setae on posterior margin; spines 1 to 3 each lacking accessory process; seta 4 just shorter than spines 2 and 3. Leg 2 ( Fig. 6F ) ornamented with extensive patches of densely-packed setules extending over lateral part of endopodal segments 2 and 3; outer spines on first and second exopodal segments elongate; spine of first segment weakly oblique, spine on second aligned close to lateral margin of ramus. Leg 3 exopod ( Fig. 6G ) with first segment lacking inner seta, bearing short, straight, outer spine not reaching as far as articulation separating second and third segments. Leg 4 ( Fig. 6H ) comprising protopodal segment and 3-segmented exopod armed with I, I, III spines; pectens on exopodal segments modified as linear membranes lying along lateral margin of segment.

Remarks: The original description by Capart (1941) was supported by figures of the dorsal habitus of the female plus individual figures of the maxilla, sternal furca, and legs 1 and 4. This species was not listed by Yamaguti (1963) but was included in the catalogue of Margolis et al. (1975). There have been few subsequent mentions of C. pagri . Oldewage & van As (1989) listed C. pagri from two sparid hosts, Pagrus caeruleostictus (Valenciennes, 1830) (as Sparus caeluleostrictus ) and S. aurata Linnaeus, 1758 , in Gambia and they attributed this record to Capart (1941). However, the two hosts recorded by Capart (1941) were, Evynnis ehrenbergi (as Pagrus ehrenbergi ) and S. aurata , so the source of Oldewage & van As’s (1989) record from P. caeruleostictus is unclear and this host record requires confirmation.

Boxshall (2018) did not include C. pagri in the newly defined C. diaphanus -species group despite the overall similarity to C. diaphanus mentioned by Capart (1941) because too little information was available on its detailed morphology. The new observations confirm the presence of other key character states typical of this species group, namely, the lack of any posterior process on the proximal segment of the antenna, the reduced size of the tine on the postantennal process, the small size of spine 1 on the distal exopodal segment of leg 1 plus the lack of an accessory process on spines 2 and 3, the extensive surface ornamentation on the endopod of leg 2, and the modified linear pectens on leg 4. Given this combination of features, C. pagri is a member of the C. diaphanus -group.

Figures

FIGURE 6. Caligus pagri Capart, 1941 adult female (body length 2.8 mm). A, habitus, dorsal; B, caudal ramus, dorsal; C, antenna, postantennal process and maxillule in situ, ventral; D, sternal furca; E, leg 1; F, leg 2; G, exopod of leg 3; H, exopod of leg 4.