Caligus haemulonis Kroyer 1863

Caligus haemulonis Krøyer, 1863

Syn: C. mauritanicus var miniscula Briian, 1924

Differential diagnosis: Female genital complex and abdomen combined about 1.3 times longer than cephalothorax; body length 2.96–3.92 mm. Male body length 1.86–3.26 mm. Female genital complex (Fig. 5 A) longer than wide, lacking distinct postero-lateral lobes: abdomen 2-segmented, first segment about 1.4 times longer than second. Male abdomen 2-segmented (Fig. 6 A); second segment about 1.6 times longer than first. Female antenna with distal claw strongly curved (Fig. 5 B). Post-antennal process large and strongly curved in both sexes (cf. Figs 5 B, 6B). Additional process present between post-antennal process and base of antenna in female (Fig. 5 B). Posterior process of maxillule with tiny blunt accessory process in male (Fig. 6 B). Sternal furca of female with incurved or straight tines (Fig. 5 C) and with small rounded processes on body surface either side of furca (Fig. 5 C); tines of sternal furca more incurved in male (Fig. 6 D). Female maxilliped with smooth myxal margin; with tiny process on inner margin of claw in some specimens (Fig. 5 C). Male maxilliped with large, acutely-pointed process on myxal margin (Fig. 6 C), opposing tip of claw. Exopod of leg 1 with seta at inner distal angle shorter than segment and about twice long as middle of distal spines; posterior margin with single, naked vestigial seta (Fig. 5 E), which can be longer in male (Fig. 6 E). Outer margin of second endopodal segment of leg 2 ornamented with typical setules. Leg 4 with robust first exopodal segment bearing marginal setule; second segment with well developed spines (Figs 5 F, 6F).

Material examined: 2 females and 1 male collected from Micropogon furnieri caught off Ubatuba and Santos, Brazil by K. Rohde: stored in the collections of the Natural History Museum, London, Reg. Nos. 1979.610-613.

59 female and 21 male syntypes labeled Caligus mauritanicus var miniscula; collected from a variety of host fishes as specified by Brian (1924); stored in 7 vials deposited in the collections of the Museum National d’Histoire Naturelle in Paris, registration numbers, MNHN Cp.279, Cp.283 - Cp.289.

2 females and 1 male collected from Girella tricuspidata caught off Coff’s Harbour, New South Wales, Australia by M. La Spina: stored in the collections of the Natural History Museum, London, Reg. Nos. 1984.12.

Distribution: Cosmopolitan.

Hosts: Ariidae: Ariopsis felis (Linnaeus, 1766) (as Hexanematichthys felis, as Galeichthys felis and as

Arius felis), Arius heudelotii Valenciennes, 1840, Bagre marinus (Mitchill, 1815) (as Felichthys

marinus and as Bagre marina);

Carangidae: Caranx sp., C. rhonchus Geoffroy Saint-Hilaire, 1817 (as C. angolensis), Lichia amia

(Linnaeus, 1758) (as Lichia vadigo), Trachurus trachurus (Linnaeus, 1758);

Ephippidae: Chaetodipterus faber (Broussonet, 1782);

Haemulidae: Anisotremus virginicus (Linnaeus, 1758), “ Haemulon elegans ”, H. sciurus (Shaw, 1803), H.

carbonarium Poey, 1860, H. plumierii Lacepède, 1801, H. macrostomum Günther, 1859, H.

steindachneri (Jordan & Gilbert, 1822), Orthopristis ruber (Cuvier, 1830), Plectorhinchus

mediterraneus (Guichenot, 1850) (and as Diagramma mediterraneum);

Kyphosidae: Girella tricuspidata (Quoy & Gaimard, 1824);

Monacanthidae: Aluterus schoepfi (Walbaum, 1792) (as Aleuterus schoepfi);

Myliobatidae: Aetobatus narinari (Euphrasen, 1790) (as Stoasodon narinari);

Polynemidae: Polydactylus quadrifilis (Cuvier, 1829);

Rachycentridae: Rachycentron canadum (Linnaeus, 1766);

Sciaenidae: Bairdiella chrysoura (Lacepède, 1802), “ Corvina cameronensis ”, Menticirrhus americanus

(Linnaeus, 1758) (as Menticirrus americanus), Micropogonias furnieri (Desmarest, 1823) (as

Micropogon furnieri), Pogonias cromis (Linnaeus, 1766), Pseudotolithus elongatus (Bowdich, 1825)

(as Corvina nigra), Sciaenops ocellatus (Linnaeus, 1766), Umbrina sp.;

Serranidae: Centropristes striata (Linnaeus, 1758);

Sparidae: Archosargus probatocephalus (Walbaum, 1792), Dentex sp., D. gibbosus (Rafinesque, 1810)

(as D. filosus), Pagrus pagrus (Linnaeus, 1758), Pagrus sp.;

Triglidae: Trigla lyra Linnaeus, 1758.

This is a widespread species that has been reported from a very large range of hosts (Margolis et al. 1975;

Luque & Takemoto 1996; Ho & Lin 2003).

Remarks: The original description of C. haemulonis does not provide a great deal of detail although it does confirm the absence of any large plumose setae from the posterior margin of the second exopodal segment of leg 1 (Krøyer 1863: Tab. IV, Fig. 3 c). In 1905 Wilson (Wilson 1905) repeated the description and copied the original figures from Krøyer but subsequently he gave a fuller description based on new material of both sexes from the Atlantic coast of the USA (Wilson 1908). It was described again by Cressey (1991) based on material from Florida and Belize, and by Luque & Takemoto (1996) using material from Brazil. There are slight inconsistencies between these descriptions which, we believe, are more due to the style of drawing than to real differences in characters. Cressey (1991) was the first to figure a tiny naked vestigial seta on the posterior margin of the distal exopodal segment of leg 1.

We place Caligus mauritanicus var miniscula as a new synonym of C. haemulonis because there are no substantive differences between these species, if we use Wilson’s (1908) redescription as the best representation of C. haemulonis.

Cressey (1991) placed both C. sciaenops Pearse, 1952 and C. setosus Pearse, 1953 in the synonymy of C. haemulonis with no discussion. As discussed below, we consider that C. sciaenops is a valid species most readily distinguished by the unusually long tines on the sternal furca. Caligus setosus is treated here as a synonym of C. sciaenops.

Caligus pagrosomi schelegeli was established by Ho & Lin (2003) as a new subspecies of C. pagrosomi, but is treated as a valid species here (see below). Both C. schelegeli and C. haemulonis share the presence of a tiny, naked vestige of a seta on the posterior margin of the distal exopodal segment of leg 1, but can be distinguished by the shorter genital complex and abdomen of C. haemulonis and by the shape of the antennal claw and post-antennal process which are strongly recurved in C. haemulonis.