Faustula clupeae ( Srivastava, 1935 ) Yamaguti, 1958

Dronen, Norman O., Blend, Charles K., Mohammed, Essa T. & Bannai, Majid, 2021, Reconsideration of the species assigned to Faustula Poche, 1926 (Digenea: Microphalloidea) with the proposal of five new genera in the Faustulidae Poche, 1926, Zootaxa 5027 (2), pp. 231-253 : 239-240

Faustula clupeae ( Srivastava, 1935) Yamaguti, 1958

(Syn. Orientophorus clupii Srivastava, 1935 )

( Fig. 4 )

Type host: Hilsa shad, Tenualosa ilisha (Hamilton) (Clupeidae) .

Type locality: India (freshwater) .

Remarks: Faustula clupeae differs from all other species in the genus by having a submedian, prebifurcal genital pore that opens immediately posterior to the posterior margin of the pharynx. It is superficially similar to F. basiri by having a preacetabular cirrus sac, but F. basiri is larger (2,100 –2,580 × 1,030 –1,100 vs 1,300 –1,500 × 700–800); the ceca terminate posteriorly short of the posterior extent of the ovary; the oral sucker as originally described as terminal; the forebody is longer (912–1,158; 42–49% vs 475; 36%); the oral sucker/pharynx width ratio is larger (1:1.8–1:2.0 vs 1:1.4–1:1.6); the ventral/oral sucker width ratio is smaller (1:0.9–1:1.1 vs 1:1.1–1:1.3); the genital pore is postbifurcal and the vitelline fields are longer. Although F. clupeae is somewhat similar to F. brevichrus in basic morphology (see Table 1) and both were described by Srivastava (1935) from the same host species ( Hilsa shad) from freshwater in India, F. clupeae differs from F. brevichrus by having a shorter esophagus (80–100; 6–7% of body length vs 120–200; 9–12%); a somewhat smaller oral sucker/pharynx width ratio (1:1.4– 1:1.6 vs 1:1.6–1:1.8); a submedian genital pore that is distinctly prebifurcal, opening near the level of the posterior end of the pharynx vs being median and located at the level of the anterior extent of the intestinal bifurcation; a shorter cirrus sac (about 280; 19% vs 310–360; 21–24%); the cirrus sac positioned from near the level of the posterior end of the pharynx to the anterior margin of the ventral sucker or slightly more posteriorly vs extending posteriorly from about the level of the intestinal bifurcation to about the level of the posterior margin of the ventral sucker or slightly more posteriorly; the ovary immediately posterior to the ventral sucker vs being some distance posterior to it and the ceca in F. clupeae are longer terminating posteriorly near the level of the posterior margin of the ovary rather than about the midlevel of the ovary (see figs. 1 & 4 of Srivastava [1935]). As noted earlier, the specimen of F. brevichrus shown in fig.1 (dorsal view) appears to have been overly compressed during fixation, which may have altered the position of some structures to some extent (i.e., the ventral sucker is shifted to the left while the cirrus sac is shifted to the right). We consider the combination of the position of the genital pore and the position of the cirrus sac to be representative of these species and sufficiently different amongst them to retain F. basiri , F. brevichrus and F. clupeae as distinct species within Faustula .

Figures

FIGURES 3–4. Diagrammatic illustrations of faustulids (ventral views): 3. Faustula brevichrus (Srivastava, 1935) Yamaguti, 1958 based on Srivastava (1935). 4. Fastula clupeae (Srivastava, 1935) Yamaguti, 1958 based on Srivastava (1935).