Indopolystoma n. gen., 2019

Chaabane, Amira, Verneau, Olivier & Preez, Louis Du, 2019, Indopolystoma n. gen. (Monogenea, Polystomatidae) with the description of three new species and reassignment of eight known Polystoma species from Asian frogs (Anura, Rhacophoridae), Parasite (Paris, France) 26 (67), pp. 1-18 : 5-6

Indopolystoma n. gen.

urn:lsid:zoobank.org:act:35517B78-23E5-4976-8D47-

776F62A5D82F

Generic diagnosis

Body large and oblong. Intestical caeca bifurcate, diverticulated, confluent posteriorly with posterior diverticulum barely entering haptor. Intestinal anastomoses usually absent but at most a single anastomosis may be present. Vas deferens extends antero-medially, opens into seminal vesicle that opens into genital bulb, armed with 8–9 genital spines. Ovary comma shaped and prominent, sinistral, in anterior 20% of body. Oviduct arises from posterior region of ovary, connected by genito-intestinal canal to sinistral caecum, receives common vitelline duct, ascends giving rise to short tubular uterus that often holds a single egg but as many as 40. Vitellaria distributed throughout body proper except in region around ovary and reproductive ducts, extending marginally into haptor; left and right vitelline ducts join to form common vitelline reservoir near ovary, with duct to oviduct. Two prominent vaginae, antero-lateral to ovary; left and right vaginal ducts connected to respective vitelline ducts. Egg operculate, oval and lacking a filament. Haptor short relative to body size (haptor/total body length ratio <0.15 for most species) with three pairs of suckers, one pair of hamuli and 16 marginal hooklets. Hamuli curved, unbranched in base (handle and guard not well separated) and with short recurved hook. Prominent big posteriormost marginal hooklet C1 (see numbering, [ 36]) with prominent broad blade and guard, in contrast with smaller hooklets C2–C8. Indopolystoma spp. are parasites of the bladder of rhacophorid frogs from Asia.

Etymology: The prefix indo refers to India, which was assumed to be the center of origin for this new genus [ 2].

Gender: neuter.

Type-species: Indopolystoma viridi n. sp.

Other species: Indopolystoma elongatum n. sp. , Indopolystoma parvum n. sp. , Indopolystoma carvirostris (Fan, Li & He, 2008) n. comb. , Indopolystoma hakgalense (Crusz & Ching, 1975) n. comb. , Indopolystoma indicum (Diengdoh & Tandon, 1991) n. comb. , Indopolystoma leucomystax (Zhang & Long, 1987) n. comb. , Indopolystoma mutus (Meng, Song & Ding, 2010) n. comb. , Indopolystoma pingbianensis (Fan, Wang & Li, 2004) n. comb. , Indopolystoma rhacophori (Yamaguti, 1936) n. comb. , Indopolystoma zuoi (Shen, Wang & Fan, 2013) n. comb. , and Indopolystoma sp.

Differential diagnosis

Within Asia, Indopolystoma can be distinguished from other polystomatid genera infecting anurans by a combination of characteristics. Unlike Diplorchis , Eupolystoma and Sundapolystoma that all have an extensive uterus, it has a short uterus like Polystoma and Neoriojatrema . Unlike Eupolystoma and Neoriojatrema that lack hamuli, it has a single pair of hamuli like Polystoma , Diplorchis and Sundapolystoma . The haptor/total body length ratio is, for all species but one, less than 0.15 while it is usually far greater for all other anuran polystomes, namely Polystoma (0.19–0.27), Diplorchis (0.15– 0.29), Eupolystoma (0.15–0.34), Neoriojatrema (0.34) and Sundapolystoma (0.28). Whereas Eupolystoma , Neoriojatrema and Sundapolystoma all have marginal hooklets of equal length, posteriormost marginal hooklet C 1 in Indopolystoma , Polystoma and Diplorchis is bigger than the remainder. However, if the posteriormost marginal hooklet C1 is the same shape as hooklets C2–C 8 in Polystoma and Diplorchis , it is far more developed with prominent broad blade and guard in Indopolystoma ( Table 4 , Figs. 2–8 ).

Figures

Figure 2. Indopolystoma viridi n. gen. n. sp. from Zhangixalus viridis. Dorsal view of holotype. (A) A drawing; (B) A photograph. Scale bar: 1 mm.

Figure 3. Indopolystoma viridi n. gen. n. sp. from Zhangixalus viridis. Hamuli from holotype and paratypes. (A–A’) Holotype; (B–H) Paratypes. Scale bar: 100 µm.

Figure 4. Indopolystoma viridi n. gen. n. sp. from Zhangixalus viridis. Marginal hooklets from paratypes. (A) Marginal hooklet C1; (B) Marginal hooklet C8; (C) Marginal hooklets C2–C7. Scale bar: 20 µm.

Figure 5. Indopolystoma elongatum n. gen. n. sp. from Zhangixalus arboreus. Ventral view of holotype. (A) A drawing; (B) A photograph. Scale bar: 1 mm.

Figure 6. Indopolystoma elongatum n. gen. n. sp. from Zhangixalus arboreus. Hamuli and marginal hooklets from holotype and paratypes. (A–A’) Holotype; (A’’–A’’’) Paratypes; (B) Marginal hooklet C1; (B’) Marginal hooklet C3; (B’’) Marginal hooklet C8. Scale bar: 100 µm (A–A’’’), 20 µm (B–B’’).

Figure 7. Indopolystoma parvum n. gen. n. sp. from Zhangixalus omeimontis. Dorsal view of holotype. (A) A drawing; (B) A photograph. Scale bar: 1 mm.

Figure 8. Indopolystoma parvum n. gen. n. sp. from Zhangixalus omeimontis. Hamuli and marginal hooklets from holotype and paratype. (A–A’) Holotype; (A’’–A’’’) Paratype; (B) Marginal hooklet C1; (B’) Marginal hooklet C2; (B’’) Marginal hooklet C6 or C7. Scale bar: 100 µm (A–A’’’), 20 µm (B–B’’).