Caligus pagrosomi Yamaguti 1939
Creators: name: Boxshall, Geoff A
name: El-Rashidy, Hoda H.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Maxillopoda
Siphonostomatoida
Caligidae
Caligus
Caligus pagrosomi

description: Caligus pagrosomi Yamaguti, 1939   
 Differential diagnosis: Female genital complex and abdomen combined nearly twice as long as cephalothorax; body length 3.94–5.30 mm. Male length 2.40–3.46 mm. Female genital complex elongate, lacking distinct postero-lateral lobes; abdomen just shorter than genital complex; 2-segmented, first segment about 2.5 times longer than second. Male genital complex elongate, wider posteriorly: abdomen 2-segmented; second segment nearly twice length of first. Post-antennal process sexually dimorphic, larger and more strongly curved in male. Additional process present between post-antennal process and base of antenna in female. Sternal furca with incurved tines; thickenings lateral to sternal furca forming paired, rounded processes. Female maxilliped with smooth medial margin. Male maxilliped with large, acutely-pointed process on myxal margin, opposing tip of claw. Exopod of leg 1 with seta at inner distal angle longer than longest distal spine but shorter than segment; posterior margin with single plumose seta longer than shortest spine. Outer margin of second endopodal segment of leg 2 ornamented with fine spinules. Leg 4 ornamented with single marginal setule on first exopodal segment; second exopodal segment with outer and middle spines on distal margin similar in length and distinctly shorter than terminal spine.   
 Material examined: 2 females and 1 male collected from Argyrosomus hololepidolus caught off Coff’s Harbour, New South Wales, Australia by K. Rohde: stored in the collections of the Natural History Museum, London, Reg. Nos. 1984.52.   
 Distribution: Western North Pacific; Japan, Taiwan, Australia.   
 Hosts: Ariidae: Arius maculatus (Thunberg, 1792);   
 Carangidae: Caranx ignobilis (Forsskål, 1755), Trachinotus blochii (Lacepède, 1801);   
 Latidae: Lates calcarifer (Bloch, 1790);   
 Lobotidae: Lobotes surinamensis (Bloch, 1790);   
 Lutjanidae: Lutjanus russellii (Bleeker, 1849);   
 Sciaenidae: Argyrosomus hololepidolus (Lacepède, 1801), Miichthys miiuy (Basilewsky, 1855),   
 “ Pagrosomus unicolor ”.   
 Caligus pagrosomi occurs on a range of teleost fishes from at least six families (Ho & Lin 2003).   
 Remarks: The original description (Yamaguti 1939) was incomplete and the best available description of this species is that of Ho & Lin (2003). The possession of a single well developed plumose seta on the posterior margin of the second exopodal segment of leg 1, in addition to the normal array of 3 spines and one seta on the distal margin, is shared only with C. alaihi. In C. enormis the single posterior margin seta is spinulate, but one of the distal margin spines is lacking. In C. dakari (as re-diagnosed above) and in C. temnodontis the plumose seta is reduced to about half the length of the adjacent seta, while in C. haemulonis the seta is further reduced to a tiny, naked vestige.
description: Published as part of Boxshall, Geoff A & El-Rashidy, Hoda H., 2009, A review of the Caligus productus species group, with the description of a new species, new synonymies and supplementary descriptions, pp. 1-26 in Zootaxa 2271 on pages 18-19, DOI: 10.5281/zenodo.190952