Length-weight relationship and certain biological aspects of the Indian white shrimp Fenneropenaeus indicus (H. Milne Edwards, 1837) exploited by trawls in the Arabian Sea off Kerala coast, India

Length-weight relationship (LWR), sex ratio and maturity of Fenneropenaeus indicus (H. Milne Edwards, 1837), was analysed based on samplings from coastal trawl fishing grounds in the Arabian Sea off Kerala coast, India. The male to female ratio (1:1.27) did not vary significantly from the hypothetical 1:1 ratio. Length at maturity (Lm50) was estimated at 122 mm total length for females. The LWR did not differ significantly between male and female shrimps. The information generated from this study will enhance knowledge on the biology of the species and assist in assessment and management of its stock

Modification of crystallinity and structure in powder processing of polytetra fluoroethylene

The modification of structure, crystallinity and orientation have been studied in powder processed polytetrafluoroethylene by various techniques. It was found that crystallinity (as determined from regression curve analysis) in unsintered samples decreased with increase of compaction pressure while in sintered specimen it increased with increase of pressure. The crystallinity was also found to vary inversely with logarithm of cooling rate. Microfocus X-ray diffraction revealed the orientation of c-axis lying preferentially in the plane perpendicular to applied pressure. There was slight variation in the lattice dimension especially the c-axis in completely sintered specimen. The infrared studies showed the presence of some of the bands depended upon the molding/sintering conditions. These various findings have been explained on the basis of compaction and recrystallization behaviour under constrained conditions

Self-consistency of relativistic observables with general relativity in the white dwarf-neutron star binary pulsar PSR J1141-6545

Here we report timing measurements of the relativistic binary pulsar PSR J1141-6545 that constrain the component masses and demonstrate that the orbital period derivative \dot Pb = (-4+/-1)x10^-13 is consistent with gravitational wave emission as described by the general theory of relativity. The mass of the neutron star and its companion are 1.30+/-0.02 Mo and 0.986+/-0.020 Mo respectively, suggesting a white dwarf companion, and extending the range of systems for which general relativity provides a correct description. On evolutionary grounds, the progenitor mass of PSR J1141-6545 should be near the minimum for neutron star production. Its mass is two standard deviations below the mean of the other neutron stars, suggesting a relationship between progenitor and remnant masses.Comment: 10 pages, 2 figures, revised version to Ap J Letter

INTERGENUS PROTOPLAST FUSION STUDIES BETWEEN MARINE STREPTOMYCES SP. ANS4 AND ESCHERICHIA COLI

Objective: To study the intergenus protoplast fusion bioactive marine Streptomyces sp ANS4 with the Escherichia coli for the strain improvement. Methods: Protoplast of both the organisms was prepared by lysozyme treatment and fused using polyethylene glycol (PEG). Fusant colonies were regenerated using regeneration medium where all the regenerated colonies are powdery in consistency. Microscopic, cultural, physiological, enzymatic and antibiotic susceptibility characteristics of one fusant culture and both the parent cultures are studied. Growth curve and bioactive metabolite production by both the parent and fusant cultures was also studied. Results: oval shaped protoplasts of both the parent cultures are clearly seen under the phase contrast microscope. All the colonies developed after protoplast fusion on regeneration medium looked like one of the parent culture Streptomyces sp ANS4. One among the 10 antagonistic colonies selected from the regeneration medium was expressed the characteristics of either or both of the parental cultures and certain new characteristics. The results of growth curve study showed that the fusant culture possess 10 hours reduction in attaining stationary phase compared to parent Streptomyces sp ANS4. The antibiotic activity of fusant culture was also higher than the parent cultures. Conclusion: The intergenus protoplast fusion between the Streptomyces sp ANS4 and the E.coli strain results in the reduction in time for secondary metabolite production and also increase in antimicrobial activity. This suggested that the potential bioactive compounds may be obtained in increased quantity from the fusant culture with lesser fermentation period

First record of the reef lobster Enoplometopus macrodontus Chan and Ng, 2008 from Indian waters

The reef lobster Enoplometopus macrodontus was caught during the deep sea trawl operations off Chavakkad from a depth of 320 m. About ten specimens were landed at the Kalamukku Fishing Harbour, Kochi. The carapace length was 66-75 mm and weight was 79.3-94.2 g. This is the first report of the species in the Indian waters. The species has a smooth carapace with hair on the abdomen, chelipeds and telson. The morphological characters along with colour pattern are describe

Trichodesmium bloom and the failure of oil sardine fishery

The occurrence of Trichodesmium blooms off Mangalore from the lalter half of February to early March in 1968 and its adverse effect on the oil sardine fishery have been reported in this account. Some of the environmental factors such as temperature, salinity, oxygen content and wind velocity and direction associated with the blooming have also been discusse

Squilloides leptosquilla, a deepsea stomatopod landed at Kalamukku Fishing Harbour, Kochi

The mantis shrimp, Squilloides leptosquilla (Brooks, 1886) was obtained from deepsea trawl operations along with the deepsea shrimps, Plesionika spinipes, Heterocarpus gibbosus and Metapenaeopsis andamanensis from the Kalamukku Fishing Harbour during September, 2008

Mixed farming or polyculture

In Kerala, nearly 75-80% of the population consume fish and their annual per capita consumption rate is about 13 kg. The rate of fish consumption is likely to go up due to increased awareness about fish as a source of cheap and highly nutritious but harmless food item. Hence there is every need to augment fish production not only to meet our food requirements but also to increase foreign exchange earnings. The current level of fish production is inadequate to fulfil all these needs. An analysis of the trend of fish production during the past few years indicates that there may not be any significant improvement in it in the coming years. In this context, measures to increase fish production are to be thought of Aquaculture is the only way to achieve this. In Kerala at present aquaculture is restricted to backwaters and inland waterbodies. In order to enhance fish production, farming of fish and other species of aquatic organisms is to be extended to inshore coastal waters for which suitable farming methods are to be adopted

സമ്മിശ്ര മത്സ്യകൃഷി (Mixed farming or Polyculture)

The rate of fish consumption is likely to go up due to increased awareness about fish as a source of cheap and highly nutritious but harmless food item. Hence there is every need to augment fish production not only to meet our food requirements but also to increase foreign exchange earnings. The current level of fish production is inadequate to fulfil all these needs. An analysis of the trend of fish production during the past few years indicates that there may not be any significant improvement in it in the coming years. In this context, measures to increase fish production are to be thought of Aquaculture is the only way to achieve this. In Kerala at present aquaculture is restricted to backwaters and inland waterbodies. In order to enhance fish production, farming of fish and other species of aquatic organisms is to be extended to inshore coastal waters for which suitable farming methods are to be adopted