Caligus pagrosomi Yamaguti, 1939

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, Zootaxa 2271, pp. 1-26 : 18-19

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.