期刊名称：International Research Journal of Environmental Sciences
电子版ISSN：2319-1414
出版年度：2013
卷号：2
期号：5
页码：17-24
语种：English
出版社：International Science Community Association
摘要：Aquatic macro-invertebrates responds to a variety of environmental conditions of rivers and streams and therefore may be used as bio-indicators for assessing water quality parameters. Seasonal variations in macrobenthic invertebrate fauna and selected physico-chemical parameters of river Tawi have been studied on monthly basis for a period of one year (September, 2011 to August, 2012). The benthic macroinvertebrate fauna of river Tawi was represented by thirteen species belonging to three groups viz. Annelida (4 taxa), Arthropoda (6 taxa) and Mollusca (3 taxa). Arthropoda was the dominant group among all and it constitutes 57.24 % of the total macrobenthic invertebrates collected. Annelida was the second dominant group and contributes 25.02% of total macrobenthic population. Whereas group Mollusca was the least abundant among all and it shared 17.72% of total macrobenthic fauna of river Tawi. The relative species diversity, species richness, dominance and evenness were calculated. The value of Simpson index ranged between H= 0 to 1.07. The maximum species diversity value was obtained in August 2012 whereas its value was 0 in the month of July. The value of Shannon-Weiner index was higher (I= 2.15) in February. Species richness in term of Maraglefs index and Menhinicks index varied between minimum valued R= 0 (July) to a maximum value R = 1.94 (Feb.) and a minimum valued R= 0 (July) to a maximum value R = 1.00 (March) respectively. The minimum evenness value was observed in July and maximum in May the values being E = 0 and E= 0.96 respectively.
