Hamacreadium longivesiculum (Yamaguti, 1952) n. comb.

(Figure 4 a)

Synonyms: Plagioporus longivesicula Yamaguti, 1952 .

Records. From an unidentified Lethrinus species off Makassar, Sulawesi, Indonesia by Yamaguti (1952).

Remarks. This species was described in detail based on two mature specimens but is no longer consistent with the modern interpretation of Plagioporus Stafford, 1904, species of which are considered to infect fresh-water fishes and possess a short excretory vesicle (Gibson & Bray 1982; Cribb 2005a; Fayton & Andres 2016). It is consistent with Hamacreadium and is distinguished from all other species of the genus by the anterior extent of the excretory vesicle, which terminates anterior to the intestinal bifurcation. This species was considered synonymous with H. interruptum by Fischthal & Kuntz (1965) and with H. mutabile by Bray & Cribb (1989), but in addition to the distinctive excretory vesicle, H. longivesiculum can be distinguished from H. mutabile by the anterior extent of the vitelline follicles and from H. interruptum by the smaller cirrus-sac and position of the genital pore.