Biodiversity Journal , 2017, 8 (4): 895–906 Bhutan freshwater gastropods and trematodes, with a warning Edmund Gittenberger 1* , Pema Leda 2, Karma Wangdi 3 & Sherub Sherub 3 ¹Naturalis Biodiversity Center, P.O. Box 9517, NL 2300 RA Leiden, The Netherlands; e-mail: [email protected] 2National Biodiversity Centre, Serbithang, Bhutan 3UgyenWangchuck Institute for Conservation and Environment, Bumthang, Bhutan *Corresponding author ABSTRACT The freshwater gastropod species that have been recorded in Bhutan are listed in this work. Distributional data for the country are presented and references are given to the original de - scriptions and to illustrations of the species that may be useful for identification. An identi- fication key is added and shells of all gastropod species are illustrated. We emphasize that some of the freshwater gastropods occurring in Bhutan may act as hosts for trematodes, as is known to be the case in other countries in Asia. These species may cause trematodiases in livestock and humans. Introductory references to the literature on snails and their parasitic trematodes are cited. KEY WORDS Gastropoda; Trematoda; freshwater; trematodiases; biogeography; Bhutan. Received 22.10.2017; accepted 10.12.2017; printed 30.09.2017 INTRODUCTION Freshwater snails may be useful as a measure for ecological water quality, as it is implemented The present paper is based on a small collection in nearby Nepal (Shah et al., 2011). Even more of shells of freshwater snails from Bhutan. It is the important, it is the fact that several species of first article ever that is devoted to freshwater snails aquatic snails that were recorded in Bhutan are es - occurring in Bhutan. All the locality data are new sential for the life cycle of trematodes and, indir- and nearly all species have not been reported from ectly, for the infection of both humans and that country before. The few species that have been livestock (Lockyer et al., 2004, Mas-Coma, 2005, mentioned being simply from ‘Bhutan’ in the lit- Chontananarth & Wongawad, 2013, and literature erature, without any further detail, may actually be therein). At the ‘Third Global Meeting of the Part- from present-day Indian territory. The shells were collected within the scope of a more general invent- ners for Parasite Control’, held in the WHO ory of the evertebrate animals of Bhutan, directed Headquarters, Geneva, in November 2004, it was by the National Biodiversity Centre in Serbithang, concluded that trematodiases have a great impact Thimphu, Bhutan, in co-operation with partner in - on human health and development (World Health stitutes like the Ugyen Wangchuck Institute for Organisation, 2005). Human fascioliasis or ‘liver Conservation and Environment, Bumthang, Bhutan, rot’, as it is called, may result from drinking con - and the Naturalis Biodiversity Center, Leiden, The taminated water or eating raw vegetables in an Netherlands. area where particular species of snails occur (Soli- 896 EDMUND GITTENBERGER ET ALII man, 2008, Ramachandran et al., 2012, Anupam Under the heading “Parasitology”, data re- Pati Tripathi et al., 2013). Because Ramachandran garding trematodes are mentioned. This is always et al. (2012) have reported human fascioliasis, for based on data in the literature for regions outside example in nearby Arunachal Pradesh and W. Bhutan. Bengal in India, the disease might occur in Bhutan A Thiara (Tarebia ) species that is reported from as well. The occurrence of trematodes with fresh- “Bhutan” in the IUCN Red List (Budha, 2010, water snails in Nepal was mentioned by Devkota 2016), without further details, is included in the et al. (2011) and Budha (2016). To judge the risk identification key, and is only dealt with in short. of these parasitic diseases, it is relevant to know The common Asian planorbid Indoplanorbis exu - what species of freshwater snails occur in a par- stus (Deshayes, 1834) is also in the identification ticular region. When that kind of data is available, key, although no records for Bhutan are known to the vast literature on trematodes and snails can be us. used. The number of shells is indicated after the loca - For more detailed descriptions of the habitats of lity number. All specimens are in the collection of the various species, we refer to a recent monograph the National Biodiversity Centre, Serbithang, Thim - on the aquatic invertebrates of the Ganga river sys- phu, Bhutan. tem, published by Nesemann et al. (2007). The References to citations in the literature are re - Middle Brahmaputra ecoregion (Mitra et al., 2010: stricted to the original descriptions and to illustra - 57), extending into southern Bhutan, is closely re - tions that may be helpful for species recognition. lated to the Ganga river system, so that the study by Nesemann et al. (2007) could be used as the basis Study area: localities for this article. Another important paper on freshwa - 1a. Dzongkhag Bumthang, NE of Yotong La, 10 ter molluscs from Nepal and North India was re- km ENE of Trongsa, 3250 meters a.s.l.; 27°31’N cently published by Glöer & Bössneck (2013). To 90°36’E; E. Gittenberger & P. Leda legit summarize the data regarding the freshwater mol - 20.IV.2015. luscs of the Eastern Himalaya, we refer to Budha et 1b. Dzongkhag Bumthang, Wangdicholing al. (2010). For an overview of the entire freshwater School Campus, 2610 meters; 27°33’N 90°44’E; biodiversity of the Eastern Himalaya, see Allen et Chimi Yuden legit, 2016 al. (2010). 2. Dzongkhag Gasa, Khame, Kabena, 1782 meters a.s.l.; 27°47’N 89°43’E; Rinchen Singye legit, I.2015. MATERIAL AND METHODS 3. Dzongkhag Haa, 15 km WSW of Paro, 2985 meters a.s.l.; 27°23’N 89°16’E; E. Gittenberger & Shells of freshwater snails were collected by se - P. Leda legit, 30.III.2016. veral participants of the “Bhutan Invertebrate Bio - 4. Dzongkhag Punakha, Toeb, Lamperi lake, diversity Survey Project”, in or near water, and 2694 meters a.s.l.; 27°30’N 89°45’E; Sherub occasionally among leaves or plants in very humid Sherub legit, 21.III.2014. places. Many areas have not been explored yet and 5a. Dzongkhag Samdrup Jongkhar, Samdrup - species with shells that are less than 1 cm in height jongkhar, 299 meters a.s.l.; 26°49’N 91°28’E; legit or width, are underrepresented because sieving ?, 11.VI.2015. aquatic bottom samples has only rarely been done, 5b. Dzongkhag Samdrup Jongkhar, Bhayter, thus relatively small shells may have been over- 309 meters a.s.l.; 26°53’N 91°44’E; Karma & Tse - looked. thup legit, 13.IV.2015. A recent monograph on the aquatic invertebrates 6. Dzongkhag Sarpang, Chuzagang, Gelephu, of the Ganga river system (Nesemann et al., 2007) Kalikhola, 235 meters a.s.l.; 26°53’N 90°31’E; and articles on freshwater molluscs from Nepal and Sonam Penjor & Sherub Sherub legit, 2013. North India (Glöer & Bössneck, 2013; Budha, 7. Dzongkhag Thimphu, 4.5 km E of Chhuzom, 2016) were used to identify the shells collected in W of Genekha, 2750 meters a.s.l.; 27°19’N Bhutan. 89°36’E; E. Gittenberger legit, 21.VI.2012. Bhutan freshwater gastropods and trematodes, with a warning 897 8. Dzongkhag Trashigang, Kanglung, campus 7b. Shell height over 1.5 cm, aperture large, meas- Sherubtse College, 1850 meters a.s.l.; 27°17’N uring ca ¾ of the total shell height......................... 91°31’E; donated, III.2016. ................................................. Lymnaea acuminata 9. Dzongkhag Trongsa, Chendebji, 2479 meters a.s.l.; 27°29’N 90°20’E. Dzongkhag Trongsa, 8a. Height usually much less than 1 cm, spire as Jigme Wangchuk & Sherub Sherubleg, 7.IX.2016. high as the aperture or higher....... Galba truncatula 10. Dzongkhag Wangdue Phodrang, Gangchhu, 8b. Height much more than 8 mm, aperture higher Phobjikha valley, 2883 meters a.s.l.; 27°26’N than the spire........................... Radix andersoniana 90°11’E; Jigme Wangchuk legit, 21.III.2015 11. Dzongkhag Wangdue Phodrang, Gangchhu, 9a. Obliquely ovoid.................... Paludomus conica Phobjikha valley, 2915 meters a.s.l.; 27°27’N 9b. Slender or very slender conical......................10 90°10’E; Jigme Wangchuk legit, 21.III.2015 12. Dzongkhag Zhemgang, Ngangla Trong; 10a. Yellowish green with darker spiral bands......... Sangay Dorji & Tsethup Tshering legit [no addi- .....................Bellamya (Filopaludina ) bengalensis tional data]. 10b. Without spiral colour bands..........................11 11a. Shell large, up to nearly 5 cm high, whorls RESULTS flattened and nearly smooth (shells from Bhutan).... ...........................................................Brotia costula KEY TO THE SPECIES 11b. Shell smaller, whorls with a spiral and a radial sculpture...............................................................12 1a. Shell broader than high: Planorbidae...............2 12a. Whorls flattened; with 5 or 6 rather coarse spiral 1b. Shell higher than broad....................................4 ridges below the periphery of the last whorl.......14 12b. Whorls moderately convex; with more than 6 2a. Much less than 1 cm broad: Gyraulus spec......3 spiral ridges below the periphery of the last whorl..13 2b. More than 1 cm broad.... Indoplanorbis spec. (not known from Bhutan) 13a. With fine spiral lines and prominent, oblique, radial elevations which may form spines................ 3a. Less than 3 mm broad, body whorl evenly roun - ....................................................Thiara (T. ) scabra ded, protoconch in line with the teleoconch 13b. Spiral and radial sculpture about equally prom- whorls............................................. Gyraulus