Phagocytic activities of splenic macrophages in Asian Sea Bass
(Lates calcarifer Bloch, 1790)

Abstract :

The changes in the population of Greater Flamingo (Phoenicopterus ruber) and influence of water depth and salinity on its population were investigated in the Point Calimere Wildlife and Bird Sanctuary, Tamilnadu, Southern India between 2004 and 2006. The mean density of Greater Flamingo ranged from 0.99 to 1656.73 km2 for the entire study period. Interestingly, in all the years of study the Greater Flamingo could not be recorded in June and September in the present study area. The density was highest in areas with 15-20 cm water depth irrespective of salinity levels. The density of flamingo was lesser in the metahaline areas (areas with salinity of 40-80 ppt) than that of the other areas. The flamingo density among the areas of depth categories (F3,191= 6.34; P < 0.001) and of different salinity levels (F3 , 191=9.75; P< 0.001) varied significantly. There was a significant association between the water depth categories and salinity levels (F 2  =137.6; P < 0.001). In lower saline areas, the flamingos used deeper waters and on the other hand in the higher saline areas they preferred shallow waters. The salinity had quadratic effect whereas the water depth had cubic influence on the density of flamingos. The Standardized Partial Regression Coefficient (E values) indicated that the salinity had the prime influence followed by water depth on the population of flamingo. When the water depth was taken into account, the prediction showed that the increase in salinity of more than 10 ppt significantly decreased the population of flamingos until the salinity of 40 ppt. On the other hand, the population of flamingo increased significantly from the water depth of 9 cm and attained the peak at 21 cm. The result suggests that the water salinity would have influenced the prey abundance and depth would have influenced the accessibility of prey.