Caligus productus Dana 1852

Caligus productus Dana, 1852

Syn: C. alalongae Krøyer, 1863

C. dentatus Heegaard, 1962

C. katuwo Yamaguti, 1936

C. lobatus Wilson, 1935

C. microdontus Heegaard, 1964

C. monacanthi Krøyer, 1863

C. mirabilis Leigh-Sharpe, 1934 nec Caligus productus O.F. Müller, 1785 (= Dinemoura producta)

Differential diagnosis: Female genital complex and abdomen combined just longer than cephalothorax; body length 4.0– 5.5 mm. Male body length 4.07 mm. Female genital complex produced into distinct postero-lateral lobes; abdomen 2-segmented, first segment just shorter than second. Male abdomen 2-segmented; second segment about twice length of first. Post-antennal process sexually dimorphic, larger and more strongly curved in male. No additional process present between post-antennal process and base of antenna. Sternal furca with straight, slightly divergent tines. Female maxilliped with small tooth-like process on myxal margin.

Male maxilliped with small process on myxal margin as in female. Exopod of leg 1 with seta at inner distal angle longer than segment, no posterior margin setae. Outer margin of second endopodal segment of leg 2 ornamented with large denticles. Leg 4 ornamented with marginal setules on first exopodal segment; distal margin spines stout, increasing in length towards terminal spine.

Material examined: 4 adult females and 1 male collected from Coryphaena hippurus caught off Tahiti by K. Rohde: stored in collections of the Natural History Museum, London Reg. Nos. 1979.482-486. 1 male collected from Thunnus albacares (Bonnaterre, 1788) caught off South Africa by R. van der Elst: stored in collections of the Natural History Museum, London Reg. Nos. 1979.916.

2 females and 1 male collected from Thunnus albacares caught off Cape Vidal, South Africa by R. Bray: stored in collections of the Natural History Museum, London Reg. Nos. 1984.130.

Distribution: cosmopolitan.

Hosts: Balistidae: Balistes polylepis Steindachner, 1876 (as Verrunculus polylepis), Balistes sp.,

Pseudobalistes flavimarginatus (Rüppell, 1829) (as Balistes flavomarginatus);

Carangidae: Naucrates ductor (Linnaeus, 1758), Seriola lalandi Valenciennes, 1833 (as S. dorsalis);

Centropomidae: Centropomus sp.;

Coryphaenidae: Coryphaena hippurus Linnaeus, 1758, Coryphaena sp.;

Elopidae: Elops saurus Linnaeus, 1766;

Monacanthidae: Monacanthus sp.;

Polynemidae: Polydactylus opercularis (Gill, 1863);

Sciaenidae: Pogonias cromis (Linnaeus, 1766);

Scombridae: Auxis thazard (Lacepède, 1800), Euthynnus affinis (Cantor, 1849) (as Euthynnus yaito),

Katsuwonus pelamis (Linnaeus, 1758) (as Katsuwonus vagans and as Thynnus pelamys), Scomber

scombrus Linnaeus, 1758, Scomberomorus cavalla (Cuvier, 1829), S. maculatus (Mitchill, 1815), S.

niphonius (Cuvier, 1832), S.sierra Jordan & Starks, 1895, Sarda orientalis (Temminck & Schlegel,

1844), S. sarda (Bloch, 1793), Thunnus alalunga (Bonnaterre, 1788), T. albacares (Bonnaterre, 1788)

(as Neothunnus albacore and as N. macropterus), T. obesus (Lowe, 1839), T. thynnus (Linnaeus,

1758);

Serranidae: Paralabrax clathratus (Girard, 1854), P. maculatofasciatus (Steindachner, 1868);

Sparidae: Calamus brachysomus (Lockington, 1880);

Sphyraenidae: Sphyraena argentea Girard, 1854.

Caligus productus utilizes a wide range of fish hosts but the most commonly reported host families are the

Scombridae and Coryphaenidae (Margolis et al. 1975; Ho & Lin 2004).

Remarks: Despite its long list of synonyms, this species is easy to distinguish from the other members of the species group by the combination of characters in the differential diagnosis. In particular, it is the only species in the group, apart from C. bocki Heegaard, 1943, which has produced lobes at the postero-lateral angles of the female genital complex. It differs from C. bocki in the possession of bifid rather than a spine-like sternal furca.

In their review of the genus Caligus, Margolis et al. (1975) listed C. monacanthi Krøyer, 1863, C. lobatus Wilson, 1935 and C. katuwo Yamaguti, 1936 as synonyms. Four further species were recognized as synonyms by Cressey (1991), C. alalongae Krøyer, 1863, C. mirabilis Leigh-Sharpe, 1934, C. dentatus Heegaard, 1962 and C. microdontus Heegaard, 1964, and these were all accepted as synonyms in Ho & Lin‘s review of the sea lice of Taiwan (Ho & Lin 2004).