Gyraulus euphraticus (Mousson, 1874)

Gurumayum, Shantabala Devi, 2024, Range extension of three freshwater gastropods in Arunachal Pradesh, North East India, Records of the Zoological Survey of India 124 (3), pp. 259-264 : 261-262

3. Gyraulus euphraticus (Mousson, 1874)

1874. Planorbis euphraticus Mousson, J. Conchyl. , 22: 44.

1834. Planorbis compressus : Hutton (nec. Michaud), J. Asiat. Soc. Beng., 3 (2): 93.

Range extension of three freshwater gastropods in Arunachal Pradesh, North East India

1919. Gyraulus euphraticus : Annandale & Prashad, Rec . Indian Mus., 18: 54, fig.7A, 8A.

Material examined: ZSI/IV/ APRC /M-439; Lohit River , Walong near Air Field , Anjaw dist.; 26/11/2022 (8 exs.); Figure 3 . Coordinates: 28.1187 N; 97.012716 E, 1112 m .

Distribution: Native: Afghanistan; China; India (Bihar, Manipur, Punjab, Jharkhand, West Bengal); Iran, Islamic Republic of Iraq; Nepal; Pakistan; Saudi Arabia; Turkey; Yemen

Diagnostic character: Shell minute with compressed 4- 5 whorls, discoidal, umbilicus wide, transparent, periphery subangulate, closely and obliquely striatulate, aperture ovate, lunate. Superficially it resembles Gyraulus convexiusculus but differs in being more depressed and more strongly carinte, opaquer and more coarsely and irregularly sculptured, body whorl deviates from the spiral of the upper whorls.

IUCN Status: Least Concern (LC)

Remarks: A Palaearctic species. Larval forms of Echinostoma ilocanum , a trematode parasite of rats and human beings and Diplodiscus amphichrus, a common Helminth parasite of intestine and rectum of anuran amphibians were recorded from this snail species ( Rao, 1989). Eight specimens were collected from Lohit River, Walong near Air Field, Aanjaw and reporting for the first time from the state.

Conclusion

Taxonomic classification of mollusca is still upgrading as many taxon have been renamed and rearranged and a lot more taxon have been synonymised based on new studies and findings ( Bouchet et al., 2017). Considering the vastness and richness of the biodiversity of the state, still, there are still lots of chances of getting species either new to science or new records in this region. Recently Sajan, et al. (2019) recorded a land snail Oxytesta shanensis new to India from Arunachal Pradesh enriching the mollusca fauna of India. However, very few new species of the Mollusca have been reported from the northeastern region so far after the works of British India may be due to a huge “taxonomic impediment” to the study of Mollusca. Inventoriztion and taxonomic studies of Mollusca fauna of the state are still in a rudimentary stage. On the contrary, plenty of new land Mollusca species have been described from other Southeast Asian regions during the last decade ( Clements & Tan, 2012; Maassen, 2006; Huang & Lee, 2016). If further dedicated studies on the taxonomic iventorization in this region are done, there may come up with many undescribed species considering the plentiful favourable habitat and presence of many unexplored and pristine regions.

Figures

Figure 3. Gyraulus euphraticus (Mousson, 1874).