Nikul B. Chavada et al /International Journal of Advances in Scientific Research 2016; 2(11): 181-187. 181 IJASR|VOL 02|ISSUE 11|2016 www.ssjournals.com International Journal of Advances in Scientific Research ISSN: 2395-3616 (Online) Journal DOI: 10.7439/ijasr Research Article Evaluation of phytoplankton diversity with Physicochemical parameters of Hemmat River, Kodinar Gujarat, India Nikul B. Chavada *1 , Kiran C. Deshmukh 2 and P.N.C. 3 1 Department of Microbiology, Somnath Science Collge-Kodinar 2 P.H.G. municipal Arts and Science College-Kalol (N.G.) 3 Prakruti Nature Clube-Kodinar (N.G.O) *Correspondence Info: Nikul B. Chavada Department of Microbiology, Somnath Science Collge-Kodinar E-mail: nikulfriends8@gmail.com Abstract Plankton refers to plants and animals that drift with the ocean currents and fresh river water .they habitants in the open waters of the sea and fresh river water. Phytoplankton always live near the surface of the sea and fresh water because, they require light for photosynthesis, they play important roll in transformation of water and carbon dioxide in to short chain sugars. The plants in the pelagic zone are exceptionally small, microscopic, and single-celled, buoyantly supported by the density of the surrounding water. Physico-chemical parameters are very important factors that play a significant role in river plankton diversity and fluctuation. We evaluated impact of Abiotic factor on plankton diversity during pre, middle and post winter analysis of Hemmat River. Keywords: Physico-chemical property of water, plankton, diversity of plankton. 1. Introduction Plankton is organisms which live suspended in the water of seas, lakes, ponds, and rivers, and not able to swim against the currents of water. This latter feature distinguishes plankton from nekton, community of actively swimming organisms like fish, larger cephalopods and aquatic mammals. There are two major groups of phytoplankton: (l) non motile, fast-growing diatoms (2) motile flagellates and dinoflagellates, which can migrate vertically in the water column in response to light. Each group exhibits a tremendous variety of cell shapes, many with intricate designs and ornamentations. The diatoms are further divided into two groups based on cell shape: (1) Pennate diatoms, which evolved first during the Late Cretaceous, are long and (2) centric diatoms, which evolved later than the pennates, are shaped like pallboxes and may have elaborate arrays of spines projecting from their cell walls. Phytoplankton has varied in physical and chemical requirements for population growth. Diatoms differ significantly with respect to motility, cell-wall composition and ornamentation, and nutritional and reproductive strategies. Diatoms have cell walls, called frustules, made of silica (the same material in glass and opal). In contrast, Dinoflagellates can have a rigid cell-wall, called a theca, made of cellulose plates, or they can have a non rigid cell membrane (no theca).these two forms of Dinoflagellates structures gave rise to the terms “armored” and “unarmored”(or “naked”) Dinoflagellates. Diatoms and Dinoflagellates can be highly ornamented, which aids in species identification. Cell- surface design on some diatoms may help focus light on chloroplast, allowing survival at greater depths where light intensity is very low. Long spines, cell shape, and the formation of chains and colonies make diatoms more difficult for predators to grasp or bite and also assist in flotation .Some Dinoflagellates form chains, whereas others have protuberances that look like wings, crowns, or horns, for similar reasons. Both groups commonly reproduce by simple cell division. Some species of diatoms and Dinoflagellates are known to produce resting stages. Resting spores in diatoms, and cysts in Dinoflagellates, allow species to survive in unfavorable condition. Dinoflagellates species have feeding veils that are extruded around such food items as diatoms. Both groups are able to absorb nutrients and vitamins into the cell and have distinct preferences for the forms of some of those nutrients.