Biology of squids

This section is. based on the data collected in the squid jigging survey made by two vessels, M.F.V. Matsya Sugandhi and M.V. Blue Fin on the southwest coast of India during the 9-month period from June 19&& to February 19&9. The data were collected onboard by the scientists of CMFRI who partici;>ated in the survey. Three species of squids were jigged during the survey, and to understand some aspects of the biology of each of these species a general idea about their distribution and Telative abundance in space and time is necessary. For this' purpose, a one-degree square where jigging was done during the period is taken as a unit area

Structure of the lipoprotein lipase-GPIHBP1 complex that mediates plasma triglyceride hydrolysis

The intravascular processing of triglyceride-rich lipoproteins by the lipoprotein lipase (LPL)–GPIHBP1 complex is crucial for clearing triglycerides from the bloodstream and for the delivery of lipid nutrients to vital tissues. A deficiency of either LPL or GPIHBP1 impairs triglyceride processing, resulting in severe hypertriglyceridemia (chylomicronemia). Despite intensive investigation by biochemists worldwide, the structures for LPL and GPIHBP1 have remained elusive. Inspired by the recent discovery that GPIHBP1 stabilizes LPL structure and activity, we crystallized the LPL–GPIHBP1 complex and solved its structure. The structure provides insights into the ability of GPIHBP1 to preserve LPL structure and activity and also reveals how inherited defects in these proteins impair triglyceride hydrolysis and cause chylomicronemia

Lipoprotein lipase is active as a monomer

Lipoprotein lipase (LPL), the enzyme that hydrolyzes triglycerides in plasma lipoproteins, is assumed to be active only as a homodimer. In support of this idea, several groups have reported that the size of LPL, as measured by density gradient ultracentrifugation, is ∼110 kDa, twice the size of LPL monomers (∼55 kDa). Of note, however, in those studies the LPL had been incubated with heparin, a polyanionic substance that binds and stabilizes LPL. Here we revisited the assumption that LPL is active only as a homodimer. When freshly secreted human LPL (or purified preparations of LPL) was subjected to density gradient ultracentrifugation (in the absence of heparin), LPL mass and activity peaks exhibited the size expected of monomers (near the 66-kDa albumin standard). GPIHBP1-bound LPL also exhibited the size expected for a monomer. In the presence of heparin, LPL size increased, overlapping with a 97.2-kDa standard. We also used density gradient ultracentrifugation to characterize the LPL within the high-salt and low-salt peaks from a heparin-Sepharose column. The catalytically active LPL within the high-salt peak exhibited the size of monomers, whereas most of the inactive LPL in the low-salt peak was at the bottom of the tube (in aggregates). Consistent with those findings, the LPL in the low-salt peak, but not that in the high-salt peak, was easily detectable with single mAb sandwich ELISAs, in which LPL is captured and detected with the same antibody. We conclude that catalytically active LPL can exist in a monomeric state

Trophic level of fishes occurring along the Indian coast

Data on the trophic level (TrL) of 707 species of exploited finfishes, crustaceans and cephalopods along the Indian coast were collected from different sources. The TrL ranges from 2.0 to 4.7 and the mean TrL is 3.5. The mean TrL of pelagic finfishes is 3.68, and the TrL decreased towards demersal habitat (3.44). A strong positive correlation exists between maximum body length of finfishes and TrL. The mean TrL of exploitation was 3.25. The complexities of assigning TrL values are discussed

Cephalopod production in India and constituent maritime states

The fishing craft and gear in which cepbalopods are obtained in India and the all India, statewise and east and west coast cephalopod production are presented. The bulk of the cephalopod catches is obtained along the west coast and trawl net accounts for major portion of landings. Maharashtra, Kerala, Tamil Nadu and Gujarat are the leading states in production

Oceanic squids - their distribution, abundance and potential in the EEZ of India and contiguous seas

FORV Sagar Sampada collected a good number of oceanic squids belonging to several families from the Indian EEZ and contiguous seas. Of these, the most important species was the purpleback flying squid Symplectoteuthis oualaniensis which forms a potential oceanic squid resource. This species was caught in pelagic trawl at depths up to.200-250 m from surface in the oceanic areas. Though the squid is known to be distributed throughout India's oceanic waters, it frequently occurred in comparatively more abundance, up to 318 squids per haul, in the northneastem Arabian Sea. There was wide variation in the size of this squid (from 20 mm to 472 mm), the largest individual weighing 4.5 kg. The diamondback squid Thysanoteuthis rhombus, the largest specimen of which measured 585 mm in length and 5.3 kg in weight, was also caught from a few stations. Besides these large species, several others belonging to families such as Onychoteuthidae, Histioteuthidae, Enoploteuthidae and Cranchiidae are also distributed in the EEZ. A large number of oceanic squids were collected at night, which is indicative of their diel vertical migration towards surface layers during night hours

Review on cephalopod resources, biology and stock assessment in Indian seas

Cephalopods are fished from the seas around India from very early times and at present contribute one of the most important exploited marine fishery resources oj the country (between 4 and 5% of the all India production). The production, which remained at very low level up to the early seventies, has shown a remarkable increase crossing the 1,00,000 tonne mark in 1994. The taxonomy, biology and stock assessment of the various exploited species have been studied since the early seventies by the CMFRI. Studies indicate that uplo 1994 tlie exploitation has remained within rational limits in almost all maritime states. The recent rapid increase in production warrants close monitoring of this short-lived resource from the viewpoint of Judicious management

Atlas of Clam Resources of Karnataka

Among the renewable molluscan resources in India, the clams of the estuarine and backwater regions provide livelihood for the poor who exploit them for their meat and shells. The clam meat is rich in protein and is also cheap when compared to prawns and fishes. It is relished by the rich and the poor alike in Karnataka. The clam shells, made up of mostly calcium carbonate, are used for industrial purposes. The export of frozen clam meat started recently during the eighties enhanced the rate of exploitation considerably in states like Kerala causing concern. Therefore the study of this resource has gained Importance in recent years