Indopolystoma viridi n. gen. n. sp., 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 : 6

Indopolystoma viridi n. gen. n. sp.

( Figs. 2 , 3 and 4 ; Table 4 )

urn:lsid:zoobank.org:act:E314A3B7-A5CE-48BA-9A21-B100556A34B9

Synonym: Polystoma sp. of Verneau et al. [ 51], Badets et al. [ 2] and Héritier et al. [ 22].

Type-host: Rhacophorus viridis (Hallowell) . Now Zhangixalus viridis (Hallowell) [ 21, 27].

Site: Bladder.

Type-locality: Tokunoshima Island, Kagoshima prefecture, Japan.

Collector: Professor Hideo Hasegawa, Department of Biology, Oita Medical University, Hasama, Oita 879-5593, Japan .

Type-specimens: Holotype ( MNHN HEL1173 ) and 10 paratypes ( MNHN HEL1174 – HEL1183 ) deposited in the Parasite Collection, Muséum national d’ Histoire naturelle, Paris, France and four paratypes ( NMB P512 – P515 ) in the Parasitic Worm Collection, National Museum, Aliwal Street, Bloemfontein, South Africa.

Etymology: The name viridi refers to the species name of its host.

Description

Description based on 15 unflattened specimens stained in carmine and mounted in Canada balsam. Body elongate, total length 8550 (5532–11,907), including haptor; greatest width 2112 (1534–2859); width at vagina 1481 (1175–1800). Tegument smooth. Haptor sub-rectangular, 773 (526–1354) long, 1184 (588–1592) wide. Haptor/total body length ratio 0.09 (0.05–0.17). Suckers 333 (242–423) in diameter. Hamuli 313 (276–373) long; with hook 66 (48–74) long ( Fig. 3A–H ). Marginal hooklet C1 40 (31–44) long; C2–C8 21.5 (16–31) long ( Fig. 4A–C ). Mouth ventral, sub-terminal and surrounded by false oral sucker; false oral sucker 394 (266–465) wide. Pharynx pyriform, 210 (124–268) long, 209 (164–244) wide. Oesophagus not visible. Lateral intestinal caeca with medial diverticula branched lacking prehaptoral and haptoral anastomoses. Testis not visible hidden by digestive tract and vitellaria. Seminal vesicle prominent and packed with sperm. Genital bulb slightly sclerotized, medio-ventral, 105 (67–124) in diameter, with eight to nine sclerotized genital spines; genital spines 40 (27–49) long. Ovary prominent, sinistral and packed with oocytes; ovary 775 (577–925) long, 401 (286–536) wide. Ootype well developed. Genito-intestinal canal present on the same side of body as ovary, joining intestinal caecum posterior to ovary. Uterus confined to area anterior to ovary holding one egg; egg 241 (191–268) long, 125 (74–165) wide. No intrauterine development of eggs observed ( Fig. 2 ).

Differential diagnosis

Indopolystoma viridi is similar to I. elongatum and I. parvum in terms of body shape, haptor/total body length ratio and shape of haptoral sclerites. However, it differs from the same two species by the general morphology of intestinal caeca and its body size (8550 µm vs. 14,791 µm for I. elongatum and 4714 µm for I. parvum ). It differs from all other species of Indopolystoma in having intestinal diverticula without anastomoses.

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.