NISCAIR Online Periodicals Repository Collection: IJMS Vol.41(4) [August 2012]

Record of bi-operculate fouling serpulid polychaete, Hydroides operculatus (Treadwell, 1929) from Diu, west coast of India

Title: Record of bi-operculate fouling serpulid polychaete, Hydroides operculatus (Treadwell, 1929) from Diu, west coast of India

Authors: Kubal, Priti; Sukumaran, Soniya; Vijapure, Tejal

Abstract: Present study consists the documentation of the bi-operculate form of fouling serpulid polychaete, Hydroides operculatus Treadwell, 1929 for the first time from India. It is provided for the first time from India. This variant was found in samples collected from Diu, North West coast of India. A perusal of literature indicates that the bi-operculate form is an advanced ontogenic stage of the polychaete rather than a different taxon. Such stages are transient and therefore rarely seen in natural populations. Polychaete species identification is intrinsic to many ecological and environmental studies. Therefore the present documentation will help prevent possible taxonomic confusion due to the presence of dual functional opercula.

Page(s): 381-384

Effect of mercury and zinc on some metabolically important enzymes of Oreochromis mossambicus

Title: Effect of mercury and zinc on some metabolically important enzymes of Oreochromis mossambicus

Authors: Rema, L.P; Philip, Babu

Abstract: Present study consists the effect of sub lethal levels of heavy metals - zinc and mercury on the activities of enzymes like HMG Co A reductase, lactate dehydrogenase and serine hydrolyase in Oreochromis mossambicus. Activities of the enzymes varied depending on the duration of exposure to the toxicants. Feasibility of measuring the enzyme activities in monitoring sub lethal metal poisoning is also discussed.

Page(s): 377-380

Effect of temperature, salinity and algal food concentration on population density, growth and survival of marine copepod Oithona rigida Giesbrecht

Title: Effect of temperature, salinity and algal food concentration on population density, growth and survival of marine copepod Oithona rigida Giesbrecht

Authors: Santhanam, P; Perumal, P

Abstract: In the present study the copepod, Oithona rigida was reared successfully fed with different algal diets such as Chlorella marina, Coscinodiscus centralis, Skeletonema costatum and Chaetoceros affinis in the hatchery condition. The total mean production of different stages of O. rigida viz., nauplii, copepodid and adults were: 21120.79, 8205.6 and 4949.9 L^-1respectively. Maximum density (3679.3 L^-1) of nauplii was attained on 11^th day of culture. The egg diameter of O. rigida was reported as 0.003 mm, just hatched nauplius (Nauplius I) and last nauplius (Nauplius VI) were 0.098 and 0.184 mm respectively. The length of early copepodid and the adult female and male were 0.312; 0.745 and 0.699 mm respectively. It is inferred that the water quality parameters such as temperature, salinity and algal prey essentially influenced the population, growth and survival of O. rigida in captive condition. The density obtained during the two months culture period indicated that, O. rigida is more sufficient for commercial seed production of fish and crustacean larvae.

Page(s): 369-376

Metal status of water in mangrove ecosystem of Maharashtra coast, India

Title: Metal status of water in mangrove ecosystem of Maharashtra coast, India

Authors: Pahalawattaarachchi, V.; Purushothaman, C. S.; Vennila, A.

Abstract: Temporal and spatial distribution of dissolved and total elements (Cu, Cd, Fe, Mn, Ni, Zn, Cr, Pb and Hg) and physicochemical parameters of water courses in the vicinity of three mangrove sites along the Maharashtra coast, India was studied. All the metals showed pronounced temporal variations in overall averages except Pb. Average concentrations of all the metals showed significant site-wise variations except Cd and Mn. Inter-relations of physicochemical parameters and metal concentrations were also observed. Contamination of toxic metals was found to be high in the sites having the influence of human habitation as well as industry.

Page(s): 359-368