Ecology of foraminifera from certain marginal marine environments from the east coast of India

Abstract

Living foraminiferal fauna from 6 marginal marine water bodies located between Visakhapatnam and Kakinada on the east coast of India has been studied in relation to certain ecological parameters. In all, 59 species of foraminifera represented by loving individuals are recognized from these water bodes. Of them, only Ammonia beccarii (Linne), A tepida (Cushman) and Quinqueloculina seminulum (Linne) are widespread and abundant in all water bodies. These species together with Eiphidium simplex Cushman and Miliammina fusca (Brady) dominate the foraminiferal populations in the area of study. Relative importance of different ecological factors in controlling the population sizes has been assessed. Most of the species except E. simplex reproduce actively in the winter (November and December). The latter on the other hand reproduces at high salinity and temperature conditions of the summer (April and May). Foraminiferal assemblages of the area are not comparable with those of similar environments bordering on the Atlantic Ocean or located at higher latitudes. In contrast they have many similarities to those of the East Malaya estuaries and Port Hacking, Australia, all these areas falling within the Indo-Pacific faunal province. Possible significance of the results in paleo-ecological investigations, especially in tropical and subtropical areas has been emphasized.