Hamacreadium hainanense Shen, 1990

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 : 162

Hamacreadium hainanense Shen, 1990

( Figure 2 b)

Synonyms: Hamacreadium hainanensis Shen, 1990 (see Liu et al. 2010); Maculifer spiralis Soota, Srivistava & Ghosh, 1970 n . syn.

Records. From the crimson snapper, Lutjanus erythropterus Bloch , bigeye snapper, Lutjanus lutjanus Bloch [as L. lineolatus (Rüppell) ] and the sin croaker, Johnius dussumieri (Cuvier) ( Perciformes : Sciaenidae ) [as Wak sina (Cuvier) ], in the South China Sea by Shen (1990). From an unidentified fish off Nicobar Island in the Andaman Sea by Soota et al. (1970) as M. spiralis . From the chicken grunt, Parapristipoma trilineatum (Thunberg) ( Perciformes : Haemulidae ), as H. mutabile , and golden snapper, Lutjanus johnii (Bloch) , and the yellowfin seabream, Acanthopagrus latus (Houttuyn) ( Perciformes : Sparidae ) [as Sparus latus Houttuyn ], as Hamacreadium lethrini Yamaguti, 1934 off Fujian, China by Wang et al. (1992).

Remarks. This species agrees with the concept of Hamacreadium , except that the excretory vesicle is depicted as branching at the posterior margin of the ventral sucker, forming a loop which unites just posterior to the pharynx. Such a condition was incorrectly depicted by Linton (1910) for Cainocreadium gulella ( Linton, 1910) Durio & Manter, 1968 [as Hamacreadium gulella Linton, 1910 ], in which the excretory vesicle in fact reaches only to the posterior margin of the ventral sucker ( McCoy 1930); it is suspected a similar misinterpretation has been made for H. hainanense . The reported sciaenid host, J. dussumieri , is apparently restricted to the Indian Ocean ( Froese & Pauly 2016) and thus may have been misidentified.

Hafeezullah & Dutta (1980) examined the specimens identified as a species of Maculifer Nicoll, 1915 by Soota et al. (1970) and concluded that they actually represented a species of Hamacreadium , suggesting H. mutabile . However the specimens are more consistent with H. hainanense in both geographical proximity and morphology; the vitelline follicles do not extend anterior to the intestinal bifurcation as was reported for H. mutabile by Linton (1910). Similarly, the specimens identified as H. mutabile and H. lethrini by Wang et al. (1992) are considered here to represent H. hainanense because in both illustrations the anterior extent of the vitelline field is bifurcal, whereas it is pre-bifrucal in H. mutabile and post-bifurcal in H. lethrini .

Figures

FIGURE 2. Reproduction with modification of type illustrations for (a) Hamacreadium cribbi Bray & Justine, 2016 and (b) Hamacreadium hainanense Shen, 1990. Abbreviations: C, caecum; Cs, cirrus-sac; Ep, excretory pore; Ev, excretory vesicle; Gp, genital pore; O, ovary; Oes, oesophagus; Os, oral sucker; P, pharynx; T, testis; U, uterus; Vf, vitelline follicles; Vs, ventral sucker. Scale: 1000 µm, 1000 µm.