http://nopr.niscair.res.in/handle/123456789/1645 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/1685 Title: Morphometry and length-weight relationship of obtuse barracuda Sphyraena obtusata (Cuvier) (Teleostomi/Actinopterygii/Sphyraenidae) from Bombay waters, west coast of India <br/> <br/>Authors: Jaiswar, A K; Parida, Pranaya K; Chakraborty, S K; Palaniswamy, R <br/> <br/>Abstract: The morphometric and meristic studies on obtuse barracuda Sphyraena obtusata from Mumbai (Bombay) waters indicated allometric relationship and high degree of homogeneity within the population. Based on the present study, the fin formula can be written as B. vii, D. 5, 1/9, P. 14, V. 1/5, A. 2/9, C 17, Ll. 90-95, two gill rakers on the first gill arch. Variations observed in some of the meristic counts when compared with findings from different locations indicate the presence of different stocks. The length-weight relationship for the species from the Mumbai waters is estimated to be W = 0.0000245L².⁷²²⁶. Deviation in the growth rate “b” observed during the present investigation from that of other countries and different region in India itself is result of variations in ecology of these geographical locations. <br/> <br/>Page(s): 307-309 Sun, 29 Aug 2004 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/1684 Title: Mosquito larvicidal potential of some extracts obtained from the marine organisms prawn and sea cucumber <br/> <br/>Authors: Thakur, Narsinh L; Mainkar, Sandhya P; Pandit, Reena A; Indap, Madhavi M <br/> <br/>Abstract: The larvicidal potential of two marine organisms was investigated by testing their non-polar to polar organic extracts against mosquito Culex pipens fatigans. In the present investigation the non-polar petroleum ether extract of prawn Nematopalaemon. tenuipes, Hendersen and polar methanol extract of sea cucumber Holothuria scabra, Jaeger body wall were found to be effective against mosquito larvae. The preliminary chemical analysis showed the presence of steroids in the active extract of prawns, whereas the presence of saponins in the active extract of sea cucumber body wall. In this context, the observed mosquito larvicidal activity could be attributed to the presence of steroids and saponins. In summary, this investigation explores the importance of marine organisms as a valuable resource for the discovery of novel insecticidal molecules. <br/> <br/>Page(s): 303-306 Sun, 29 Aug 2004 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/1683 Title: Depositional environment and silting in the Sharavati estuary, central west coast of India <br/> <br/>Authors: Hegde, V S; Kanchanagouri; Gosavi, D; Hanamgond, P T; Huchchannavar, G K; Shalini, G; Bhat, M S <br/> <br/>Abstract: Variation in textural characters (silt sand ratio, mean size, sorting and skeweness) of the Sharavati estuarine sediments has been studied to understand their depositional environment. Seventeen locations within the estuary and two locations just at the entrance of the sea were selected for the study. During September 2000, medium grained (1.36-1.86φ), well sorted to moderately well sorted sediments were observed in the estuary, whereas they were fine grained (2.67-3.φ) and poorly sorted in the entrance of the sea (0.84). The estuarine sediments were relatively fine-grained during December 2000 (postmonsoon) (1.3-2.18φ) and February 2001(premonsoon) (1.15-2.3φ) as compared to the monsoon season. The siltation in the estuary is mainly due to offshore source brought by tidal currents followed by mixing of saline and fresh water in the estuary. <br/> <br/>Page(s): 296-302 Sun, 29 Aug 2004 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/1682 Title: Distribution of certain ecological parameters and foraminiferal distribution in the depositional environment of Palk Strait, east coast of India <br/> <br/>Authors: Gandhi, M.Suresh; Rajamanickam, G.V <br/> <br/>Abstract: Out of 102 species, only 36 species are living ones. The total distribution of foraminifera is higher at Devipattinam and Attankarai followed by Mandapam, Thondi and Kodiyakkarai whereas at Kottaipattinam, Manalmelkudi and Sethubavachattiram it is noticed to be in the lower order. Organic matter and living species show positive relation. The lack of relationship between dead species and the organic matter has suggested that the dead species recorded in the sediments must have been primarily drifted/transported as empty calcareous shells. From the sand/silt/clay ratios, it is inferred that the sediments are normally sandy in nature but silty sand dominates at deeper depths. Carbonate content establishes a weak negative correlation with all parameters except organic matter and dead species. Fluctuation of salinity values in Attankarai indicates the influx of fresh water from Vaigai river. Based upon the ecological parameters the stations have been grouped into different environments. Among them, bar environment registers low species diversity than the other three. The following species are appreciably distributed in different stations namely Ammonia beccarii, Elphidium crispum, Rosalina globularis, Asterorotalia trispinosa, Osangularia venusta and Pararotalia nipponica. This strait is influenced by an unique environment of high order of siltation leading to the depletion of living forams. The present study highlights the abundance of living species in places of high organic matter. The ongoing process of active siltation is manifested in the bar environment and the same is reflected in the low organic matter and less species diversity. <br/> <br/>Page(s): 287-295 Sun, 29 Aug 2004 22:58:59 GMT