NOPR Collection:

Bothid larvae (Pleuronectiformes-Pisces) of the Indian Ocean

2016-07-20T05:29:58Z

Title: Bothid larvae (Pleuronectiformes-Pisces) of the Indian Ocean Authors: Devi, C B Lalithambika Abstract: The larvae of bothids were found to be sparsely distributed in the Indian Ocean, being only 7.6% in IIOE collections (1960-65) and 13.5% in FOR V Sagar Sampada (1986-90) samples. They were confined mostly to the coastal waters. Their density was high in Bay of Bengal, with maximum number in Malacca Strait. Bay of Bengal may be considered as the cradle for larval both ids holding 45.9% while only 38.4% occurred in the Arabian Sea. They were more during northeast monsoon period. There is no direct relationship between abundance of zooplankton biomass and the number of bothid larvae. The present report includes 23 species belonging to 9 genera from the Indian Ocean, their regional, seasonal as well as diurnal variation s. Engyprosopon grandisquamis dominated contributing to 23.2% of the total larvae. Numerically the incidence of bothid .larvae suggested a uniform pattern of distribution during the two monsoons. Yet certain species in the Arabian Sea like Arnoglossus tapeinosoma, Engyprosopon multisquama, E. latifrons, E. grandisquamis and A. aspilos aspilos showed a preference to north east monsoon while E. cocosensis, Bothus myriaster, B. pantherinus, Arnoglossus intermedius and Crossorhombus valde-rostratus showed preference to south west monsoon. In Bay of Bengal Engyprosopon grandisquamis was dominant during both the seasons with a preference for S.W. monsoon and larvae of Engyprosopon cocosensis, E. latifrons, Arnoglossus tapeinosoma and Bothus pantherinus dominated during N.E. monsoon. In the Arabian Sea, eleven species were dominant in the night samples whereas in the Bay of Bengal only nine species showed affinity towards darkness. The study has enabled delineation of the spawning grounds, incidence and relative abundance thus providing data for the stock assessment and management of the economically important bothid fishery resources of the Indian Ocean. Page(s): 198-210

Distribution of zooplankton in relation to water movements in Kakinada bay, east coast of India

2016-07-20T05:26:16Z

Title: Distribution of zooplankton in relation to water movements in Kakinada bay, east coast of India Authors: Mohan, P Chandra; Raman, A V; Sreenivas, N Abstract: Plankton collections were made from three stations in the bay to study the annual variations in distribution of zooplankton in relation to temperature, salinity, turbidity, pH and dissolved oxygen. The annual mean value of biomass and numerical abundance at three stations were 1.79, 1.80, 2.91 ml.m^-3 and 38482, 39269, 38447 no. m^-3 respectively at three stations. The prevailing northerly and southerly currents along the coast also influence the distribution of the planktonic organisms. In spite of these wide fluctuating conditions we can distinguish characteristic populations within the bay region which show regular annual cycles and colonization. Marked depletion in the number of species was observed during the last 2-3 decades on account of deterioration of water quality of the bay, which is known to receive effluents from the adjacent industries and city. Page(s): 192-197

Zooplankton community of Bhayandar and Thane salt pans around Bombay

2016-07-20T05:28:51Z

Title: Zooplankton community of Bhayandar and Thane salt pans around Bombay Authors: Mustafa, S.; Nair, Vijayalakshmi R.; Govindan, K. Abstract: The zooplankton community of the salt pans of Bhayandar and Thane was stud ied based on the contribution of microzooplankton and meso-macrozoop lankton. Population of microzooplankton was about 4 times more in Bhayandar as compared to Thane salt pan. The protozoan ciliate Fabrea salina dominated the microzooplankton community. The meso-macrozooplankton standing stock was more at Thane (av 1.7g wet wt/m³) as compared to Bhayandar (av 1.4 g wet wt/m³). However, group diversity was more at Bhayandar. A reduction in group diversity to the order of 50% was observed from creek to crystallizer associated with high salinity regime. Copepods were the most abundant group at both the salt pans. Calanoids dominated the Bhayandar salt pan while cyclopoids were predominant at Thane. Decapods and mysids were common in the area. During the monsoon season mysids were dominant in the crystallizer and condenser of Thane. Artemia was observed only at Bhayandar. In general the salt pans sustain a fairly rich zooplankton standing stock with low diversity. Page(s): 184-191

Trophic structure and levels of selected metals in the zooplankton community of Thane-Bassein creek, Bombay

2016-07-20T05:27:10Z

Title: Trophic structure and levels of selected metals in the zooplankton community of Thane-Bassein creek, Bombay Authors: Nair, Vijayalakshmi R; Krishnamurti, Asha Jyothi; Gajbhiye, S N Abstract: Community structure of zooplankton at 4 locations, 2 in the coastal waters off Bombay and 2 in interior Thane-Bassein Creek System were studied for a period of one year. Copepods as the major herbivore community contributed 76-83% to total zooplankton population. Decapods were relatively more in the outer (av.11%) as compared to interior zone (av.7%). Population density of carnivores were 2-4 times more in the polluted interior segment. Among the different metals studied Cu and Zn contributed 60-89% of the total elements accumulated. In general, concentration of Zn was higher than Cu in different groups. Also levels of Zn in polluted locations were 2 times higher than the outer zone. The maximum concentrations of metals was observed in gelatinous organisms which included a variety of carnivores. Metal concentration in copepods was lower than carnivores. The lowest concentrations of metals in decapods could be due to the effective elimination of a part of the concentrated metal through periodic moulting. Page(s): 173-183