Environmental factors affecting water mites (Acari: Hydrachnidia) assemblage in streams, Mangde Chhu basin, central Bhutan

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Mer Man Gurung
Cheten Dorji
Dhan B. Gurung
Harry Smit


Water mites were sampled from 15 tributary streams of Mangde Chhu river in Zhemgang and Trongsa districts, Central Bhutan in pre-monsoon (April–May) and post-monsoon (October–November) of 2021. A total of 802 individuals were collected belonging to seven families and 15 genera. The accumulation curve suggests that the sampling efforts were adequate to give a proper overview of genera composition for elevations 500–2,700 m. Eleven genera—Aturus, Kongsbergia, Woolastookia, Atractides, Hygrobates, Lebertia, Piona, Sperchonopsis, Monatractides, Pseudotorrenticola and Testudacarus—and five families—Aturidae, Hygrobatidae, Lebertiidae, Pionidae, and Protziinae—are new records for Bhutan. Independent sample t-tests of genera richness (t, (26) = 0.244, p = 0.809); genera evenness (t, (26) = 0.735, p = 0.469); Shannon diversity index (t, (26) = 0.315, p = 0.755) and dominance (t, (26) = -0.335, p = 0.741) showed no significant differences between pre- and post-monsoon assemblages. Species abundance was also not significantly different (t, (28) = -0.976, p = 0.330). Principal component analysis indicated that the diversity of water mites is negatively associated with several environmental variables including chloride (r = -0.617), ammonia (r = -0.603), magnesium hardness (r = -0.649), total hardness (r = -0.509), temperature (r = -0.556), salinity (r = -0.553), total dissolved solids (r = -0.509) and electrical conductivity (r = -0.464). Diversity was positively correlated with altitude, mainly caused by the higher Palaearctic genera diversity. Similarly, Pearson’s correlation test showed that there was significant negative correlation between mite abundance and the water physio-chemical parameters salinity (r = -0.574, p = 0.032), electrical conductivity (r = -0.536, p = 0.048), total dissolved solids (r = -0.534, p = 0.049), total hardness (r = -0.621, p = 0.018), and chloride concentration (r = -0.545, p = 0.036), indicating sensitivity of water mites to pollution.

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Abelho, M., R. Rui & M. Matilde (2021). Salinity affects freshwater invertebrate traits and litter decomposition. Diversity 13(11): 599. https://doi.org/10.3390/d13110599

APHA. (2017). Standard Methods for examination of water and wastewater. In: American Public Health Association (APHA), Washington, 1504 pp.

Cook, D.R. (1967). Water mites from India. Memoirs of the American Entomological Institute 9: 1–411.

Currinder, B. (2017). Land use and water quality in Bangladesh and Bhutan. University of Pennsylvania, 57 pp. https://repository.upenn.edu/mes_capstones/69.

Da Costa, J.B., S. Rodgher, L.A. Daniel & E.L.G. Espíndola (2014). Toxicity on aquatic organisms exposed to secondary effluent disinfected with chlorine, peracetic acid, ozone, and UV radiation. Ecotoxicology 23(9): 1803–1813. https://doi.org/10.1007/s10646-014-1346-z.

Delaune, K.D., D. Nesich. J.M. Goos & R.A. Relyea (2021). Impacts of salinization on aquatic communities: Abrupt vs. gradual exposures. Environmental Pollution 285: 117–636. https://doi.org/10.1016/j.envpol.2021.117636

Di Sabatino, A., H. Smit. R. Gerecke. T. Goldschmidt. N. Matsumoto & B. Cicolani (2008). Global diversity of water mites (Acari: Hydrachnidia; Arachnida) in freshwater. Hydrobiologia 595: 303–315. https://doi.org/10.1007/s10750-007-9025-1

Di Sabatino, A., P. Martin. R. Gerecke & B. Cicolani (2002). Hydrachnidia (Water mites), pp. 105–133. In: Rundle, S.D., A.L. Robertson & J.M. Schmidt-Araya (eds.). Freshwater Meiofauna: Biology and Ecology. Backhuys Publishers, Leiden, The Netherlands.

Di Sabatino, A., R. Gerecke & P. Martin (2000). The biology and ecology of lotic water mites (Hydrachnidia). Freshwater Biology 44(1): 47–62. https://doi.org/10.1046/j.1365-2427.2000.00591.x

Dorji, K. (2016a). Utility of an existing biotic score method in assessing the stream health in Bhutan. PhD Thesis, Queensland University of Technology.

Dorji, Y. (2016b). Water: securing Bhutan’s future. Asian Development Bank. http://hdl.handle.net/11540/7507

Dorji, T., F. Sheldon & S. Linke (2020). Fulfilling nature needs half through terrestrial-focused protected areas and their adequacy for freshwater ecosystems and biodiversity protection: A case from Bhutan. Journal for Nature Conservation 58: 125894: 1–6. https://doi.org.10.1016/j.jnc.2020.125894

Gascho-Landis, A.M. & J.A. Stoeckel (2016). Multi‐stage disruption of freshwater mussel reproduction by high suspended solids in short and long‐term brooders. Freshwater Biology 61(2): 229–238. https://doi.org/10.1111/fwb.12696

Gerecke, R. & H. Smit (2022). Water mites of the genus Lebertia Neuman, 1880 from the eastern Himalayas (Acari: Hydrachnidia: Lebertiidae). Acarologia 62(2): 302–316. https://doi.org/10.24349/esot-nc22

Gerecke, R., G. Weigman. A. Wohltmann & E. Wurst (2007). Order Acari – general introduction and key to the major groups, pp. 14–37. In: Gerecke R. (ed.). Chelicerata: Araneae, Acari I. Süßwasserfauna von Mitteleuropa. https://doi.org/10.1007/978-3-662-55958-1_2

Giri, N. & O.P. Singh (2013). Urban growth and water quality in Thimphu, Bhutan. Journal of Urban and Environmental Engineering 7(1): 82–95. https://doi.org/10.4090/juee. 2013.v7n1.082095

Goldschmidt, T. (2016). Water mites (Acari, Hydrachnidia): powerful but widely neglected bioindicators - a review. Neotropical Biodiversity 2(1): 12–25. https://doi.org/10.1080/23766808.2016.1144359

Goldschmidt, T., J.E. Helson & D.D. Williams (2016). Ecology of water mites assemblages in Panama – First data on water mites (Acari, Hydrachnidia) as bioindicator in the assessment of biological integrity of neotropical streams. Limnologica 59: 63–77. https://doi.org/10.1016/j.limno.2016.03.007

Grandin, U. (2006). PC‐ORD version 5: A user‐friendly toolbox for ecologists. Journal of Vegetation Science 17(6): 843–844. https://doi.org/10.1111/j.1654-1103.2006.tb02508.x

Griffith, M.B. (2017). Toxicological perspective on the osmoregulation and ion regulation physiology of major ions by freshwater animals: teleost fish, Crustacea, aquatic insects, and Mollusca. Environmental Toxicology and Chemistry 36(3): 576–600. https://doi.org/10.1002/etc.3676

Gurung, D.B., S. Dorji, U. Tshering & J.T. Wangyal (2013). An annotated checklist of fishes from Bhutan. Journal of Threatened Taxa 5(14): 4880–4886. https://doi.org/10.11609/JoTT.03160.4880-6

Gurung, M.M., C. Dorji, D.B. Gurung & H. Smit (2022). Checklist of water mites (Acari: Hydrachnidia) of the Himalayan and Tien Shan Mountains. Ecologica Montenegrina 57: 8–23. https://doi.org/10.37828/em.2022.57.2

Gurung, P.B. & T. Dorji (2014). Macroinvertebrate diversity and relationship with environmental variables in the headwater streams of Toebirongchhu sub-watershed, Bhutan. NeBIO 5(3): 5–10.

Kent, M.L., C. Buchner. C. Barton & R.L. Tanguay (2014). Toxicity of chlorine to zebrafish embryos. Diseases of Aquatic Organisms 107(3): 235–240. https://doi.org/10.3354/dao02683

Korkmaz, D. (2001). Precipitation titration: “determination of chloride by the Mohr method”. Methods 2(4): 1–6.

Mani M.S. (2013). Ecology and Biogeography of High-Altitude Insects. Springer. https://doi.org/10.1007/978–94–017–1339–9

Miccoli, F.P., P. Lombardo & B. Cicolani (2013). Indicator value of lotic water mites (Acari: Hydrachnidia) and their use in macroinvertebrate-based indices for water quality assessment purposes. Knowledge and Management of Aquatic Ecosystems 411(8): 1–28. https://doi.org/10.1051/kmae/2013075

NEC (2016). National Integrated Water Resources Management Plan 2016. National Environmental Commission, Thimphu, 131 pp.

Negi, S., A.K. Dobriyal & P. Bahuguna (2021). Biodiversity and monthly density fluctuations of water mites in Khankra gad, a spring-fed tributary of river Alaknanda, Pauri Garhwal in Uttarakhand, India. Journal of Applied and Natural Science 13(1): 258–267. https://doi.org/10.31018/jans.v13i1.2568.

Norbu, S., S. Tshering & Y. Tenzin (2021). Assessment of fish biodiversity in Amo Chhu river basin. Bhutan Journal of Animal Science 5(1): 58–65.

Ofenbock, T., O. Moog. S. Sharma & T. Korte (2010). Development of the HKHbios: a new biotic score to assess the river quality in the Hindu Kush-Himalaya. Hydrobiologia 651(1): 39–58. https://doi.org/10.1007/s10750-010-0289-5

Park, G.E., H.N. Oh & S.Y. Ahn (2009). Improvement of the ammonia analysis by the phenate method in water and wastewater. Bulletin of the Korean Chemical Society 30(9): 2032–2038.

Patang, F., A. Soegianto & S. Hariyanto (2018). Benthic macroinvertebrates diversity as bioindicator of water quality of some rivers in East Kalimantan, Indonesia. International Journal of Ecology 2018(Article ID 5129421): 1–11. https://doi.org/10.1155/2018/5129421

Pešić, V., H. Smit & A. Saboori (2012). Water mites delineating the Oriental and Palaearctic regions—the unique fauna of southern Iran, with description of one new genus, one new subgenus and 14 new species (Acari: Hydrachnidia). Zootaxa 3330(1): 1–67.

Pešić, V., H. Smit & M.M. Gurung (2022a). Torrenticolid water mites of Bhutan. Genera Torrenticola Piersig, 1896 and Neoatractides Lundblad, 1941 (Acari: Hydrachnidia: Torrenticolidae). Acarologia 62(3): 821–860. https://doi.org/10.24349/xn0u-5px2

Pešić, V., H. Smit & M.M. Gurung (2022b). Neumania bhutana sp. nov. a new water mite from Bhutan (Acari, Hydrachnidia: Unionicolidae). Ecologica Montenegrina 54: 53–56. https://doi.org/10.37828/em.2022.54.7

Pozojević, I., A. Brigić & S. Gottstein (2018). Water mite (Acari: Hydrachnidia) diversity and distribution in undisturbed Dinaric karst springs. Experimental and Applied Acarology 76(1): 123–138. https://doi.org/10.1007/s10493-018-0294-3

Pozojević, I., V. Pešić. T. Goldschmidt & S. Gottstein (2020). Crenal habitats: sources of water mite (Acari: Hydrachnidia) diversity. Diversity 12(9): 1–13. https://doi.org/10.3390/d12090316.

Rai, R., S. Sharma. D.B. Gurung. B.K. Sitaula & R.D.T. Shah (2020). Assessing the impacts of vehicle wash wastewater on surface water quality through physico-chemical and benthic macroinvertebrates analyses. Water Science 34(1): 39–49. https://doi.org/10.1080/11104929.2020.1731136

Rasaily, B., V.J. Kalkman. O. Katel. C. Dorji & B. Suberi (2021). Composition of the dragonfly fauna at different altitudes in Bhutan based on larval samples. International Dragonfly Fund 160: 20 pp.

Resh, V. H. (2008). Which group is best? Attributes of different biological assemblages used in freshwater biomonitoring programs. Environmental Monitoring and Assessment 138: 131–138. https://doi.org/10.1007/s10661-007-9749-4

Roberts, H. & B.S. Palmeiro (2008). Toxicology of aquarium fish. Veterinary clinics of North America: Exotic Animal Practice 11(2): 359–374. https://doi.org/10.1016/j.cvex.2007.12.005

Ryder, D., K. Vernes. L. Dorji. S. Armstrong. C. Brem. R. Di Donato & I. Simpson (2015). Experimental effects of reduced flow velocity on water quality and macroinvertebrate communities: implications for hydropower development in Bhutan. Proceedings of the Bhutan Ecological Society, 21 pp.

Savić, A., A. Zawal. E. Stępień. V. Pešić. R. Stryjecki. L. Pietrzak & A. Szlauer- Łukaszewska (2022). Main macroinvertebrate community drivers and niche properties for characteristic species in urban/rural and lotic/lentic systems. Aquatic Sciences 84(1): 1–14. https://doi.org/10.1007/s00027-021-00832-5

Smit, H. (2020). Water mites of the world with keys to the families, subfamilies, genera and subgenera (Acari: Hydrachnidia). Monografieën van de Nederlandse Entomologische Vereniging, 12: 1–774.

Smit, H. & M.M. Gurung (2022). Description of the first species of the water mite genus Aturus Kramer, 1875 from the Himalaya Mountains (Acari: Hydrachnidia: Aturidae). Zootaxa 5169(5): 494–496. https://doi.org/10.11646/zootaxa.5169.5.8

Smit, H., & H. Van der Hammen (1992). Water mites as indicators of natural aquatic ecosystems of the coastal dunes of the Netherlands and northwestern France. Hydrobiologia 231(1): 51–64.

Smit, H., V. Pešić & M.M. Gurung (2022). The water mite genus Sperchon Kramer, 1877 in Bhutan (Acari: Hydrachnidia: Sperchontidae), with the description of three new species. Acarologia 62(3): 754–762. https://doi.org/10.24349/pfqk-ad5d

Smith, I.M., D.R. Cook & B.P. Smith (2001). Water mites (Hydrachnidiae) and other Arachnids, pp. 551–659. In: Thorp, J.H. & A.P. Covich (eds.). Ecology and Classification of North American Freshwater Invertebrates 2nd edition. Academic Press, San Diego, California.

Smith, I. M., D.R. Cook & B.P. Smith (2010). Water mites (Hydrachnidiae) and other Arachnids, pp. 485–586. In: Thorp, J.H. & A.P. Covich (eds.). Ecology and Classification of North American Freshwater Invertebrates 3rd Edition. Academic Press, San Diego, California.

Soucek, D., J.T.K. Linton. C.D. Tarr, A. Dickinson, N. Wickramanayake, C.G, Delos & L.A. Cruz (2011). Influence of water hardness and sulfate on the acute toxicity of chloride to sensitive freshwater invertebrates. Environmental Toxicology and Chemistry 30(4): 930–938. https://doi.org/10.1002/etc.454

Stryjecki, R. & A. Bańkowska (2018). A faunistic and ecological characterization of the water mites (Acari: Hydrachnidia) of the Bukowa River (central-eastern Poland). Acta Biologica 25: 77–94. https://doi.org/10.18276/ab.2018.25-07

Stryjecki, R., A. Zawal, E. Stępień, E. Buczyńska, P. Buczyński, S. Czachorowski & P. Śmietana (2016). Water mites (Acari, Hydrachnidia) of water bodies of the Krąpiel River valley: interactions in the spatial arrangement of a river valley. Limnology 17(3): 247–261. https://doi.org/10.1007/s10201-016-0479-6

Tsering, K., E. Sharma, N. Chettri & A.B. Shrestha (2010). Climate change vulnerability of mountain ecosystems in the Eastern Himalayas. International Center for Integrated Mountain Development (ICIMOD), 77 pp.

Wangchuk, J. & K. Dorji (2018). Stream macro-invertebrate diversity of the Phobjikha Valley, Bhutan. Journal of Threatened Taxa 10(1): 11126–11146. https://doi.org/10.11609/jott.3138.10.1.11126-11146

Wangchuk, K., M.R. Douglas, J. Claussen, D.P. Philipp & M.E. Douglas (2018). One Fish, Two Fish: An Initial Assessment of Fish Species Diversity in Bhutan. In 148th Annual Meeting of the American Fisheries Society, Atlantic City, New Jersey.

Wieçek, M., P. Martin & A. Lipinski (2013). Water mites as potential long-term bioindicators in formerly drained and rewetted raised bogs. Ecological Indicators 34: 332–335. https://doi.org/10.1016/j.ecolind.2013.05.019

Willingham, W.T., R.V. Thurston, R.J. Luedtke & R.C. Russo (2016). Toxicity of Ammonia and Nitrite to Aquatic Macroinvertebrates. Intermountain Journal of Sciences 22(4): 138–139.

Wood, C.M. (2019). Toxic responses of the gill. In: Schlenk, D. & W.H. Benson (eds.). Target Organ Toxicity in Marine and Freshwater Teleosts. CRC Press, 89 pp.

Xu, J., R.E. Grumbine, A. Shrestha, M. Eriksson, X. Yang, Y.U.N. Wang & A. Wilkes (2009). The melting Himalayas: cascading effects of climate change on water, biodiversity, and livelihoods. Conservation Biology 23(3): 520–530. https://doi.org/10.1111/j.1523-1739.2009.01237.x

Young, W.C. (1969). Ecological distribution of Hydracarina in north central Colorado. American Midland Naturalist 82: 367–401. https://doi.org/10.2307/2423785

Zawal, A., A. Bańkowska, G. Michoński, M. Grabowski, A. Szlauer-Łukaszewska, T. Czernicki & V. Pešić (2020). Environmental determinants of water mite (Acari: Hydrachnidia) distribution in the ancient Lake Skadar system. Journal of Great Lakes Research 46(5): 1090–1098. https://doi.org/10.1016/j.jglr.2019.06.002

Zawal, A., R. Stryjecki, E. Stępień, E. Buczyńska, P. Buczyński, S. Czachorowski & P. Śmietana (2017). The influence of environmental factors on water mite assemblages (Acari, Hydrachnidia) in a small lowland river: an analysis at different levels of organization of the environment. Limnology 18(3): 333–343. https://doi.org/10.1007/s10201-016-0510-y

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