A review of the Caligus productus species group, with the description of a new species, new synonymies and supplementary descriptions Author Boxshall, Geoff A Author El-Rashidy, Hoda H. text Zootaxa 2009 2271 1 26 journal article 10.5281/zenodo.190952 70e42274-cb72-4b9b-88df-c287a84a93d1 1175-5326 190952 Caligus sciaenops Pearse, 1952 Syn: C. setosus Pearse, 1953 C. cresseyi Ho & Lin, 2003 C. epinephali [sic]: Cressey (1991) Differential diagnosis: Female genital complex and abdomen combined about 1.2 times longer than cephalothorax; body length 3.1–4.2 mm . Male body length unknown. Female genital complex subrectangular, without distinct postero-lateral lobes; about as long as abdomen. Abdomen 2-segmented, first segment markedly longer than second. Male abdomen 2-segmented, first segment about half length of second. Post-antennal process large and strongly curved in female. Antenna claw not strongly curved. No additional process present between post-antennal process and base of antenna in female. Sternal furca with long, tapering tines. Female maxilliped with smooth medial margin. Exopod of leg 1 with seta at inner distal angle longer than longest spine but shorter than segment; no vestiges of posterior margin setae; first exopodal segment broad, with strongly convex posterior margin. Outer margin of second endopodal segment of leg 2 ornamented with fine spinules. Distal spines on exopod of leg 4 all similar in length but terminal spine just longer than other 2. Material examined: none Distribution: Jamaica , Gulf of Mexico (Texas coast). Hosts: Sciaenidae : Sciaenops ocellatus (Linnaeus, 1766), Cynoscion nebulosus (Cuvier, 1830) , Cynoscion nothus (Holbrook, 1848) , Leiostomus xanthurus Lacepède, 1802 . The only known hosts of C. sciaenops are sciaenids ( Pearse 1952 ; 1953 ; Cressey 1991 ). Remarks: Cressey (1991) placed C. sciaenops in the synonymy of C. haemulonis with no discussion. The general body size and shape given by Pearse (1952) is consistent with C. haemulonis and, although the proportional lengths of the two abdominal segments in the female do not match with the description of C. haemulonis , the abdomen appears abnormally slender in Pearse’s figures of females ( Pearse 1952: Fig. 49, 59 ). The male figured by Pearse (1952: Fig. 58) has a 2-segmented abdomen and the proportional lengths of the two segments match those of C. haemulonis . However, we consider the shape of the sternal furca, with its unusually long tines, to be an important distinction between C. sciaenops and C. haemulonis . In this character, and in other characters such as the strongly recurved post-antennal process and weakly recurved antennal claw, C. sciaenops resembles the species described by Cressey (1991) as C. epinephali [sic] Yamaguti, 1936 . In an earlier study, Ho & Lin (2003) concluded that the Caligus material described by Cressey (1991) as C. epinephali [sic] was not conspecific with C. epinepheli of Yamaguti (1936) and proposed Caligus cresseyi Ho & Lin, 2003 as a new name, based on Cressey’s description. We consider that the oldest available name for this taxon is Caligus sciaenops Pearse, 1952 , and we recognise C. cresseyi Ho & Lin, 2003 as a junior subjective synonym of C . sciaenops . Caligus setosus has a female body length of 3.17 mm , within the range of C. sciaenops , the sternal furca has long tapering tines and the post-antennal process is strongly curved in the female ( Pearse 1953 ), as in C. sciaenops . On this basis we treat C. setosus as a junior subjective synonym of C. sciaenops , but this needs confirmation.