Hamacreadium

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 : 180

Key to species of Hamacreadium recognised here

1a. Genital pore distinctly extra-caecal........................................................................ 2

1b. Genital pore caecal or inter-caecal, not extra-caecal...........................................................3

2a. Vitelline follicles confluent in forebody, distinctly interrupted about ventral sucker, extend anteriorly at least to the intestinal bifurcation; cirrus-sac cylindrical...................................................... H. interruptum ( Fig. 3 a)

2b. Vitelline follicles not confluent in forebody, not interrupted, distinctly post-bifurcal; cirrus-sac clavate, sigmoid.................................................................................................. H. lutiani ( Fig. 4 b)

3a. Anterior extent of vitelline follicles distinctly pre-bifurcal.....................................................4

3b. Anterior extent of vitelline follicles bifurcal or post-bifurcal....................................................5

4a. Vitelline follicles extend to anterior margin of pharynx...................................... H. phyllorchis ( Fig. 5 b)

4b. Vitelline follicles terminate posterior to pharynx.............................................. H. mutabile ( Fig. 1 )

5a. Anterior extent of excretory vesicle pre-bifurcal........................................ H. longivesiculum ( Fig. 4 a)

5b. Anterior extent of excretory vesicle distinctly post-bifurcal.....................................................6

6a. Anterior extent of vitelline follicles post-bifurcal.............................................. H. lethrini ( Fig. 3 b)

6b. Anterior extent of vitelline follicles bifurcal................................................................ 7

7a. Cirrus-sac sigmoid, extends dorsal to posterior half of ventral sucker............................... H. cribbi ( Fig. 2 a)

7b. Cirrus-sac straight to curved, entirely anterior to ventral sucker or extending dorsal to anterior half of ventral sucker.......8

8a. Ovary four-lobed...................................................................... H. morgani ( Fig. 5 a)

8b. Ovary many-lobed................................................................... H. hainanense ( Fig. 2 b)

Figures

FIGURE 1. Hamacreadium mutabile specimen SI NMNH IZ # 1402929 collected by Dr M. J. Andres from Lutjanus griseus in the Gulf of Mexico. Ventral perspective of (a) adult worm, (b) terminal genitalia and (c) ovarian complex. Abbreviations: C, caecum; Cs, cirrus-sac; E, egg; Ep, excretory pore; Ev, excretory vesicle; Ga, genital atrium; Gp, genital pore; Lc, Laurer’s canal; Mg, Mehlis’ gland; Mp, male pore; O, ovary; Oes, oesophagus; Oo, ootype; Os, oral sucker; P, pharynx; Pp, pars prostatica; Sr, seminal receptacle; Sv, seminal vesicle; T, testis; U, uterus; Vd, vitelline duct; Vf, vitelline follicles; Vr, vitelline reservoir; Vs, ventral sucker. Scale: 1000 µm, 300 µm, 300 µm.

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.

FIGURE 3. Reproduction with modification of type illustrations for (a) Hamacreadium interruptum Nagaty, 1941 and (b) Hamacreadium lethrini Yamaguti, 1934. 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.

FIGURE 4. Reproduction with modification of type illustrations for (a) Hamacreadium longivesiculum (Yamaguti, 1952) n. comb. and (b) Hamacreadium lutiani (Shen, 1990) n. comb. 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.

FIGURE 5. Reproduction with modification of type illustration for (a) Hamacreadium morgani Baz, 1946 and (b) Hamacreadium phyllorchis (Bilqees, 1976) Cribb, 2005. 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.