I9 X 5-] Fauna of the Chilka Lake : Introduction. 



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luxuriantly, forming dense thickets that extend upward from the bottom to the 

 surface for a height of at least four feet. This plant dies down in the rainy season 

 and masses of dead and dying weed then break loose, float on the water and are 

 thrown up on the shore or entangled amongst rocks at the edge. The new growth 

 makes its appearance in autumn and is well advanced by the middle of November, 

 when the plant is in flower on the surface. Its maximum luxuriance is not, however, 

 reached until February or March, after the flowering season is practically over. 



A plant more widely distributed in both parts of the lake, but much less con- 

 spicuous and luxuriant, is Halophila ovata, a species that creeps along the bottom 

 sending up stems of four to six inches high at short intervals. These bear relatively 

 large ovate leaves which form a favourite basis for a few simply organized sessile 

 animals. Halophila, which is practically confined to a muddy bottom, is found all 

 over the main area and in the inner part of the outer channel, in patches that often 

 reach a considerable size. Small masses of this plant are constantly being detached, 

 probably by diving ducks and other water-birds, and float from place to place. The 

 plant is found in an active condition at all times of the year. 



Several other aquatic Phanerogams occur in the lake, but are not of sufficient 

 abundance to have any faunistic interest. 



Among semi-aquatic flowering plants by far the most conspicuous is the reed 

 (Phragmites) that covers Nalbano and grows among the rocks on many of the promon- 

 tories. It reaches a height of at least 10 feet. Several other smaller grasses and at 

 least one species of rush also grow in the shallows of the main area, but not in 

 sufficient quantities to attract a special fauna. 



The higher algae are absent from the lake and those of the less specialized groups 

 that occur are not as a rule of any great zoological interest. Several unicellular 

 forms are found, however, in considerable quantities in the plancton at some seasons, 

 notably species of Dinoflagellata, while a certain number of diatoms live on the 

 bottom or elsewhere. Submerged rocks and stones are usually coated with simple 

 and branched filamentous algae of a bright green or a brown colour, but the growth 

 is never very luxuriant. A slimy dark green species with an offensive odour some- 

 times covers small patches of the bottom in the main area and is fairly common along 

 the shore of the Satpara peninsula. Its presence seems to be peculiarly inimical 

 to animal life. As the water sinks after the rains, this alga, in drying, forms a thin 

 felt-like substance and is gathered by the villagers at Satpara and used by them 

 instead of paper for wrapping up parcels. 



From a zoological point of view the most important feature of the vegetation 

 on the shores of the lake is the total absence of mangrove swamps. Except where 

 the beach is sandy, as along the outer parts of the outer channel, or stony, as 

 around many of the islands and promontories of the main area, cultivated fields or 

 grazing grounds extend down to the water's edge, if the former do not actually 

 encroach upon the water. There are, therefore, comparatively few trees close to the 

 margin ; firewood is also scarce and trunks and branches are not allowed to go to 

 waste or to float away. This fact is of faunistic importance in reference to the 



