Volume 97, Issue 2
March 1988, pages 117-180
pp 117-131 March 1988
The state of marine pollution along the 7000 km long coastline and 2·015×106 km2 exclusive economic zone of India is summarized. The coastal water receives 4·1 km3 of domestic sewage and 0·41 km3 of industrial wastes. Nearly 447 million tonnes of oil and its products are transported through the Arabian Sea and Bay of Bengal with the result that some of our coastal areas particularly adjoining the large cities are getting polluted. Increased eutrophication and decrease in dissolved oxygen associated with the generation of toxic hydrogen sulphide have been observed at several places. Heavy metal concentrations are largely within the acceptable limits in water and in biota excepting in a few areas. Organochlorine and pesticides residues have often been found to be high in zooplankton and in the sediments near the confluence of the river and the sea, indicating their land origin. Oil pollution is a chronic problem in the northern Indian Ocean. Several of the endangered ecosystems have now been offered protection by declaring them as marine parks. It is recommended that to maintain coastal waters clean, wise and judicious use of the ocean must form an integral part of our planning.
pp 133-139 March 1988
Quantitative changes in the total proteins, carbohydrates and lipids during embryogenesis ofAtractomorpha cremulata (Fab) are provided. The protein and carbohydrate contents of the egg increase after 4 days of incubation until just prior to hatching when there is a slight fall. Lipid content shows a steep increase on the 6th day of incubation. Qualitative gel electrophoretic analysis revealed as many as 14 protein fractions at various stages of embryogenesis. These observations are discussed based on densitometric scanning studies.
pp 141-149 March 1988
The overgrowth interactions and spatial relationships amongst 7 interacting bryozoan species in the coastal waters of Bombay were studied. All interspecific encounters involved overgrowth, there being a total absence of ties. On the other hand, in intraspecific encounters, occurrence of ties was quite high. It was observed that a superior overgrowth of any species did not determine its relative abundance. None of the 7 species studied won in all its overgrowth interactions with the others. It was further observed that the success of cheilostome species to dominate over the others did not depend on their ability to grow over through any one particular encounter angle. Ranking of competitive overgrowth abilities amongst the 7 species studied did not form a simple hierarchial sequence but instead formed a competitive network.
pp 151-160 March 1988
The level and content of different biochemical constituents were investigated over a period of one year (January–December 1982) in foot, gonad digestive gland complex and viscera of two tropical cerithiids, inhabiting two different regions of backwaters. Their seasonal indices exhibited bimodal pattern of cycling and this trend was more predominant in gonad digestive gland complex and foot. In all the body components of both species, the biochemical content was found to show considerable changes when compared to their levels. In both the cerithiids, the gonad digestive gland depicted remarkable variations with the season, followed by foot. The viscera did not show much variation when compared to other body components. The carbohydrates and glycogen of both the species showed a primary peak in March and a secondary peak in September indicating maturity of gonads. This was followed by a decline in their constituents which might be due to spawning. Lipid utilisation was also observed in both the animals next to carbohydrates and glycogen. Proteins were least utilised in the process of reproduction. Thus a carbohydrate-oriented metabolism was recorded in both the species. The results were compared with the other molluscs.
pp 161-167 March 1988
The organic, acetic and sorbic acids at 1% level were fed to albino rats and Indian desert gerbils in whole and broken maize corn. The gerbils were highly sensitive to maize treated with organic acids. The reproduction studies showed that the gerbils had more number of abnormalities with regard to the young ones. The sorbic acid treated maize possessed a teratogenic potential and it induced cannibalism. In case of albino rats no such abnormalities were found. However, abortion, delayed gestation period and cannibalism were common. Based on the data obtained it was postulated that the gerbils could be used as alternatives to albino rats in toxicological studies.
pp 169-173 March 1988
Data on the fecundity ofHypoththalmichthys molitrix was statistically computed and the relationships between fecundity and body measurements were found to be linear. The fecundity was more closely related to the body weight (r=0·8439,F=15·37 at 1% level of significance) than fish length (r=0·704,F=8·953 at 5% level of significance) and the ovary weight (r=0·6794,F=8·3839 at 5% level of significance).
pp 175-180 March 1988
The results of static and acute bioassay studies onDaphnia lumholtzi (Cladocera) andCypris subglobosa (Ostracoda) to the varying dosages of Cu, Cd and Zn were presented. The 96 h, LC50 values forDaphnia were found to be 0·009, 0·083, 0·437 and forCypris 0·25, 0·687, 8·3 mgl−1 for Cu, Cd and Zn respectively. This indicates thatDaphnia is very sensitive whileCypris has a good amount of resistance. The rank order for toxicity of 3 metals is Cu>Cd>Zn. The study indicates that the waters getting polluted by heavy metals even at low concentration would remove the population of fish-food organisms without directly effecting fish fauna, thus making water body unfit for fishery use.