Spatial Distribution of Benthic Macroinvertebrate Fauna in Mountain Streams of Uttarakhand, India - Aquatic Ecosystem: Biodiversity, Ecology and Conservation - page 30

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Spatial Distribution of Benthic
Macroinvertebrate Fauna
in Mountain Streams
of Uttarakhand, India

Prakash Nautiyal , Asheesh Shivam Mishra ,
and Vijay Prakash Semwal

Abstract
The large-scale (regional) distribution pattern for the benthic macroinver-
tebrate fauna has been investigated for the fi rst time in the west Himalayan
streams. The macroinvertebrate fauna in the river basins of Uttarakhand
region consists of Trichoptera, Ephemeroptera, Diptera, Coleoptera and
Plecoptera. The faunal composition varied from the western (Yamuna) to
eastern part (the Ramganga) of the Himalaya as the share of Trichoptera
and Ephemeroptera is relatively low in the Yamuna river basin but domi-
nates from Bhagirathi to Ramganga basin. The marginal increase of
Diptera, Coleoptera and Mollusca in the Yamuna basin accounted for the
decline of Trichoptera and Ephemeroptera in this basin. Leptoceridae and
Glossosomatidae are the dominant taxa in the river Alaknanda and
Mandakini, respectively, while Glossosomatidae and Philopotamidae are
simultaneously dominant in the Bhagirathi, all trichopterans. Heptageniidae
is dominant in the Ramganga and Yamuna, while Heptageniidae and
Glossosomatidae are simultaneously dominant in the Pindar. The taxo-
nomic composition is similar in the basins; Bhagirathi (Mandakini and
Alaknanda), Yamuna and Ramganga, Pindar. The characteristic taxa
varied among the forest type. No taxa are characteristic to Deodar forest.
The characteristic taxa varied from oak in the west to pine forest type
in the east. The scrapers (Blephariceridae, Limnephilidae, Planorbidae,
Lymnaeidae), predators (Dixidae, Perlidae) and gatherers (Ephemerellidae,
Baetidae, Hydropsychidae) characterised the pine forest. Similarly, the
shredders (Leptoceridae) and fi lterers (Simuliidae) characterised the oak