Environmental implication on chamber accretion of <Emphasis Type="Italic">Neogloboquadrina pachyderma</Emphasis> (Ehrenberg) in southern Indian Ocean

Morphological variations with respect to the number of chambers in Neogloboquadrina pachyderma (Ehrenberg) were investigated in 25 surficial sediments of Indian Ocean taken along the N-S transect between 9.69° N and 55.01° S latitude and 80° E and 40° E longitude. The number of chamber was counted for at least 40 specimens picked for each sample. The average number of chamber was correlated with the average temperature and salinity along the changing latitude. The results showed a high correlation between the number of chambers and temperature and salinity. It was noted that number of chambers decreases from equatorial to polar region. The carbonate saturation and nutrient availability could possibly be other causes for the change in number of chambers. The results of this study, if applied on the subsurface marine sediments, will bear implications on paleoclimatic condition in the Indian Ocean region.