Abstract
Studies on the macrofauna from the five selected stations spread over a distance of about 25 km. in the Cochin backwater showed that the benthic biomass was greater in the regions which were near the sea. The abundance of organisms decreased progressively towards the more estaurine zone. The bivalves, gastropods and polychaetes were the most predominant forms in the sample. The presence of larger bivalve,Meretrix ovum and the polychaete,Diopatra neopolitana at the stations near the sea considerably increased the benthic biomass at these stations. Organisms of lesser importance were crabs, fish, ophiuroids and sea anemones. Studies on meiobenthos which was restricted to the estuarine zone only showed a high degree of abundance of foraminiferans and nematodes. Foraminiferans were more abundant at stations nearer the sea suggesting their preference for marine conditions. The nematodes on the other hand were more dominant at stations away from the sea. An examination of the substrata at five stations showed that the conditions were different from one place to the other. A substratum of fine and coarse sand seems to support a denser benthic population.
The distribution and abundance of macro and meiobenthos when compared with the seasonal changes in physico-chemical conditions of the backwater was investigated. It appeared that perhaps the most important factor governing the quantitative distribution of benthos is the salinity. Settling stages of bivalves and gastropods, which are of purely marine origin, though appear in large numbers, do not survive in estuarine conditions. Areas of high salinity in the backwater are those which are rich in nutrients and chlorophyll and were found to support a denser benthic population.
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References
Annandale, N. .. “Fauna of the brackish ponds of Port Canning, Lower Bengal,”Rec. Indian Mus., 1907,1.
————— and Kemp, Stanley.. “Fauna of the chilka lake,”Introduction Mem. Indian. Mus., 1915,5, 1–20.
Balakrishnan, A... “Variation of salinity and temperature in Ernakulam Channel,”Bull. Cent. Res. Inst. Trivandrum, 1957,5, 7–9.
Blegvad, H... “Quantitative investigations of bottom invertebrates in the Kattegat with special reference to plaice food,”Rep. Danish Biol. Sta., 1930,36, 1–16.
Bristow, R. C...History of Mud Banks, Vols. 1 and 2, Cochin Government Press, Ernakulam, 1938.
Cherian, P. V... “Studies on the salinity and temperature variations in the port of Cochin,”Journal of the T.D. and P.A., 1963,9, 7–21.
Cole, G. A... “An ecological study of the microbenthic fauna of two Minnesota lakes,”Amer. Midl. Nat., 1955,53, 213–30.
Eggleton, F. E... “A limnological study of the profundal bottom fauna of certain freshwater lakes,”Ecological Monographs, 1931,1, 231–332.
George, M. J. and Krishna Kartha, K. N... “Surface salinity of Cochin backwater with reference to tide,”J. mar. biol. Ass. India, 1963,5, 178–84.
Jones, N. S... “Marine bottom communities,”Biol. Rev., 1950,25, 283–313.
—————.. “The bottom fauna of the south of the Isle of Man,”J. Anim. Ecol., 1951,21, 132–44.
—————.. “The fauna and biomass of muddy sand deposits off Port Erin., I.O.M.,” Ibid., 1956,25, 217–52.
Konstantinov, A. S... “Method of estimating the production of organisms serving as food for fishes,”Nauck. Dokl. Vyssh. Shk., 1960,4, 59–62.
Krishnamurthy, K. N... “Preliminary studies on the bottom macrofauna of the Tungabhadra reservoir,”Proc. Indi. Acad. Sci., 1960,53 B, 96–103.
Kurian, C. V... “A preliminary survey of the bottom fauna and bottom deposits of the Travancore Coast within 15 fathom line,”Proc. nat. Inst. Sci. India, 1955,19, 747–76.
McIntyre, A. D... “Quantitative differences in the fauna of boreal mud associates,”J. mar. biol. Ass. U.K., 1961,41, 599–616.
Mulicki, Z... “Ecology of the more important benthic invertebrates in the Baltic Sea,”Pr. norsk. Inst. rub. Gdyni., 1957,9, 313–79.
Panikkar, N. K. and Aiyar, R. G. “The brackish water fauna of Madras,”Proc. Ind. Acad. Sci., 1937,6, 284–337.
Qasim, S. Z. and Reddy, C. V. G. “Estimations of plant pigments of Cochin backwaters during the monsoon months,”Bull. Mar. Sci., 1965. (in press).
Ramamirtham, C. P. and Jayaraman, R... “Some aspects of the hydrographical conditions of the back-waters around Willingdon Island (Cochin),”J. mar. biol. Ass. India, 1963,5, 170–77.
Rajan, S. .. “Environmental studies of the Chilka Lake. 2. Benthic animal communities,”Indian J. Fish., 1966. (in press).
Sanders, H. L... “Oceanography of long Island Sound. 1952–54. X. Biology of marine bottom communities,”Bull. Bingham Oceanogr. Coll., 1956,15, 345–414.
Segerstrale, S. G... “Fluctuations in the abundance of benthic animals in the Baltic area,”Soc. Scient. Fenn. Comment. Biol., 1960,23, 1–19.
Seshappa, G... “Observations on the physical and biological features of the inshore seabottom along the Malabar Coast,”Proc. nat. Inst. Sci. India, 1953,19, 256–79.
Stickney, A. P. and Stringer, L. D. “A study of the invertebrate bottom fauna of Greenwich Bay, Rhode Island,”Ecology, 1957,38,, 111–22.
Thamdrup, H. M... “Der van Veen-Bodengreifer. Vergleichsvers uche uber die Leistungsfahigkeit des van Veen und des Petersen-Bodengreifers,”J. Cons. int. Explor. Mer., 1938,13, 206–12.
Thorson, G... “Contributions to the animal ecology of the Scoresby Sound Fjord-complex (East Greenland),”Medd. Om. Gronl, 1934,100, 1–68.
—————.. “Bottom communities inTreatise on Marine Ecology and Paleoecology, Vol. I—Ecology, Chapter 17”,Geol. Soc. Amer. Mem., 1957,67, 461–534.
Ursin, E... “Efficiency of marine bottom samplers of the van Veen and Petersen types,”Medd. Damm. Fisk-og Hay. Ny. Ser., 1954,1, 1–8.
Welch, P. S. .. “Limnological methods,”Philadelphia Blakiston, 1948, pp. 1–381.
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Communicated by Dr. N. K. Panikkar,f.a.sc.
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Desai, B.N., Krishnan Kutty, M. Studies on the benthic fauna of Cochin backwater. Proc. Indian Acad. Sci. 66, 123–142 (1967). https://doi.org/10.1007/BF03052094
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DOI: https://doi.org/10.1007/BF03052094