A Study on Species distribution and Diversity of macro-fauna of River Tawa-A Tributary of River Narmada in Madhya Pradesh, India

This study is aimed to collect information about the macrofauna diversity of Tawa River. The Tawa River joins to Narmada at district Hoshangabad (Madhya Pradesh). During the study 8 sites were selected for the investigation. collections of samples were done from the eight sampling sites of the river. Collected samples were identified up to species level and their diversity and richness were analyzed. Shannon index for diversity and margalef index for richness were used for the study. Total 48 taxa of macrofauna have been recorded from the identified sampling stations. Benthic fauna of phylum Arthropoda was found in dominant position in the study and phylum Mollusca was found in second position. CONTACT Charu Tiwari charuzoology05@gmail.com Department of zoology, Barkatullah University, Bhopal, Madhya Pradesh,


Introduction
River ecosystems are most important lotic fresh water habitats for many aquatic animals and benthic animals are one of these animal. Benthic animals are generally found in both of fresh water habitats i.e. -lotic habitats and lentic habitats. Benthos spends their whole life in bottom of aquatic ecosystem because of their feeding nature. Basically they are detritus feeders and divided in to two types -microzoobenthos and macrozoobenthos. Macro benthos are those animals which can be seen with naked eyes. Their diversity and distribution are good indicators of water quality of an ecosystem that's why they are known as bioindicators. In the present investigation diversity and distribution of Macroinvertebrates were recorded for the period of two years from July 2017 to June 2019. The study was focused on two main phyla of macrozoobenthos community of arthropoda and mollusca. Macrozoobenthos show sessile and sedentary behavior. Aquatic organisms are common indicator of aquatic environmental conditions. 1 Macrozoobenthic fauna serve as a biological indicator of aquatic ecosystem. 2 Physicochemical quality of water is the factors that influence species composition of a water body. 3 Macrobenthos are good source of fish food and their food chain. 4 They are Ecological engineers of ecosystems. 5 Fresh water ecosystem was the conservation priority during International decade Action 6 and in the present time also. Periodical bioassessment of taxonomic diversity of aquatic ecosystem play an important role for nature and ecological protection. Different measures are used in bioassessment for fresh water. 7 Macrozoobenthos due to their special characteristics are indicator of the water quality of an aquatic ecosystem. 8, 9 The abundance of macrozoobenthos are depending on its surrounding environment. 2 composition of benthic community is directly related to water quality. 10 The present research was aimed to study the distribution of benthic macro fauna of Tawa river.

Material and Methods Study area
Tawa River is one of the major tributaries of Narmada in the central India. The Tawa originates from Satpura hills of Betul district and flows towards Hoshangabad District of (Madhya Pradesh). The Tawa joins to Narmada river at Bandrabhan village of Hoshangabad. The preserve forest BORI is situated along the Tawa. Bori sanctuary of the preserve forest is very famous part of Biosphere of Panchmarhi of Hoshangabad district.

Study Ssites
Total 8 sites were identified for the research. Their geographical positions are shown in the Table 1. These sites arranged from upstream to downstream and joins to Narmada in Bandrabhan village at district Hoshangabad.

Protocoll
Selected sites were visited periodically to gather samples of benthic macro-fauna. To collect samples, various types of gears like surber sampler, D-net sampler, kick net sampler, and grab sampler etc. were used according to river bed of the sites. 0.5 to 0.6 micron mesh sized sieve were used to collect benthic macro fauna. Separated fauna were washed carefully and stored in labeled plastic bottles. 4% formalin were used for benthos preservation. Collected animals were identified upto the species level. Microscope and hand lens were used to observe detailed features of the animals.
Diversity and Richness Index collected samples were recorded in a manner of tabulation chart. After the collection of data, statistical analysis was done. In the present paper two important diversity index were analysed.

Conclusion
In the present study of macrozoobenthos diversity of Tawa river, dominant phylum was Arthropoda followed by Mollusca. The range of Shannon diversity index was lies between 2.93 to 2.22 which are indicating moderate pollution level in the sampling sites. Species diversity value in the range of 1.00 to 3.00 indicates moderate pollution in the water. Margalef diversity index value varied from 2.26 to 5.53 in the study and indicates low species richness. Road connectivity increased human activities in the study area. Moreover, Agriculture activities, dam, activity of power plant, over exploitation and human disturbance in the study area may be cause to change habitat structure and low of species richness.