Pacificreadium serrani (Nagaty & Abdel Aal, 1962) Durio & Manter, 1968

Martin, Storm B., Cutmore, Scott C., Ward, Selina & Cribb, Thomas H., 2017, An updated concept and revised composition for Hamacreadium Linton, 1910 (Opecoelidae: Plagioporinae) clarifies a previously obscured pattern of host-specificity among species, Zootaxa 4254 (2), pp. 151-187 : 176-177

Pacificreadium serrani (Nagaty & Abdel Aal, 1962) Durio & Manter, 1968

Synonyms: Hamacreadium serrani Nagaty & Abdel Aal, 1962 ; Hamacreadium caranxi Saoud, Abu Sinna & Ramadan, 1977 n . syn.; Hamacreadium ghardagense Ramadan, 1983 .

Records. From the coral rockcod, Cephalopholis miniata (Forsskål) [as Serranus miniatus (Forsskål) ] ( Serranidae ) in the Red Sea by Nagaty & Abdel Aal (1962c) as H. serrani . From an unidentified Epinephelus species off New Caledonia and from E. merra and the barcheek coral trout, Plectropomus maculatus (Bloch) (Serranidae) , off Heron Island, Great Barrier Reef, Australia by Durio & Manter (1968). From the coastal trevally, Carangoides coeruleopinnatus (Rüppell) [as Caranx altissimus Jordan & Seale] ( Carangidae ) in the Red Sea by Saoud et al. (1977) as H. caranxi . From Variola louti in the Red Sea by Ramadan (1983) as H. ghardagense . From the common coral trout, Plectropomus leopardus (Lacépède) (Serranidae) , off Heron Island by Bray & Cribb (1989). From P. leopardus off New Caledonia by Bray & Justine (2007) and Justine et al. (2010a).

Remarks. This species is characterised by striking pre-bifurcal diverticulate extensions of the excretory vesicle, originally incorrectly associated with the intestine (see Durio & Manter 1968; Bray & Cribb 1989). Based on this character and following further collection of morphologically consistent specimens from serranids of the Great Barrier Reef and off New Caledonia, Durio & Manter (1968) proposed the genus Pacificreadium Durio & Manter, 1968 for this species.

The excretory vesicle was not described for H. caranxi or H. ghardagense . Bray & Cribb (1989) synonymised H. ghardagense with P. serrani . Bray & Cribb (1989) also considered the genital pore to be medial in the description of H. caranxi , but did not transfer it to Cainocreadium . The description of H. caranxi appears to be more similar to the descriptions of P. serrani and H. ghardagense from the Red Sea than it does to species of Cainocreadium . A carangid host is anomalous for either P. serrani or species of Cainocreadium .