Spatio-temporal variation in macro-invertebrate assemblage structure of kayar khola, Chitwan Nepal
Date
2022
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Department of Zoology
Abstract
The spatial and temporal variations of the macro-invertebrate assemblages in rivers and
streams of Nepal are poorly understood. The macro-invertebrate communities and their
relationships with environmental variables were studied in Kayar Khola, Chitwan for
one year (November 2020 to August 2021) covering four seasons. Each and every
sampling station was visited once in each season. Macro-invertebrate sampling was
conducted at each sampling station from 11 am to 2 pm by using a D-frame Net with a
mesh size of 0.5mm. Altogether 42 Families belonging to 17 Orders, 5 Classes and 3
Phyla were found in present study. Among the collected macro-invertebrates,
Hydropsychidae (20.20%) was recorded to be the most dominant family and followed
by Thiaridae (15.76%), Heptageniidae (12.02%), Baetidae (9.43%), and Psephenidae
(5.09%) respectively. Family Viviparidae (0.05%) was less dominant and found only in
the spring season at site C of Kayar Khola. The Order Trichoptera was found to be the
most dominant order with 408 individuals. The highest Shannon-Weiner diversity index
(2.39) was observed during winter season whereas the lowest value (1.61) observed in
summer season. Maximum family richness value (21.0) was found in winter season and
the minimum (7.75) found in summer season. The correspondence analysis (CCA)
reveals a significant correlation between macro-invertebrate assemblage and
environmental variables. Cluster analysis depicts that similarity between macroinvertebrates
decreases
as
the distance
of sites increases.
Description
Keywords
Macro invertebrate, Chemical parameters