| 1 | Role of mangrove forests of Pichavaram as fish nurseries An account of the food web pattern of 67 species of fishes, belonging to 51 genera and 33 families, of the Pichavaram mangrove ecosystem, is given. Of these, 32 species were omnivores, 30 species carnivores, and only 5 species herbivores. The food of the omnivores consisted of varying combinations of plant, animal and detrital materials. Strict detritus-feeders were absent, although about 88% of omnivores take detritus as part of food. This could be a result of the shallowness of the channels (usually from 40 to 150 cm depth) and high detritus potential of the ecosystem. The occurrence of considerable percentage (about 45%) of carnivorous fishes might be related to the impressive availability of the prey population like the prawn larvae and juveniles and nematodes and copepods and amphipods. Due to high suspended materials in the water, the penetration of sunlight into the channels would restrict the growth of microflora, algae, seaweeds and plants. The nature of the substratum was not conducive to a thick growth and colonisation of plants, like algae and seaweeds. Hence herbivore proportion of fish population was minimum. The stress of monsoon on feeding norms is discussed Source: Jeyaseelan, M.J.P.; Krishnamurthy, K. Proc. Indian Natl. Sci. Acad. (B: Biol. Sci.). 46(1); 1980; 48-53. 0129.
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