New evidences on the distribution of predatory pelagic sharks in the tuna grounds of the Indian Ocean

Since the commencement of the exploitation of oceanic tuna resources of the Indian Ocean seventeen years ago, the hooked rates for the tuna species have declined in many areas of the Ocean but there are no evidences of such a trend in the case of the sharks. As a result, the percentage composition of sharks in the longline catches and the percentage of the tuna catch damaged by sharks show an increase. Hence there is an urgent need for innovation of the existing longline gear in order to increase the fishing efficiency for hooking the tuna species with a corresponding reduction in its efficiency for hooking sharks. At the beginning of this fishery, hooked sharks were discarded at sea, at a later stage the liver and fins were taken and the carcass discarded and presently the sharks are also brought along with the tuna catch. Though the shark meat has a very low market value it is brought in order to cover up for the declining tuna catches. Thus it has become very necessary to increase the demand for shark meat by developing products or by-products utilizing shark meat and ensuring the successful continuity of the tuna longline fishery. The pattern of distribution of shark species in the time grounds of the Pacific, Indian and Atlantic Oceans and also the predation of hooked tunas by sharks were discussed earlier (Sivasubranianiam 1963, 1964 and 1966). Some contribution to these studies is made in this paper based on new data become available.

Studies on the phytoplankton of inshore and offshore waters off Colombo and some data on the hydrological conditions of these waters

The present paper gives a comparative account of the hydrological conditions and phytoplankton within the Continental Shelf and beyond the Continental Shelf. 54 water samples were taken for hydrological analysis and 18 surface tows for plankton.

Some preliminary observations on the biology of Strongylocentrotus lividus (Lamarck)

The present study of Strongylocentrotus lividus is an attempt to add to the knowledge in this field with particular reference to a tropical species of whose biology little is known. The aim of the study was to examine the growth of the animals in relation to the development of their gonads, to elucidate the food preferences of the sea urchins and to study their associations with other animals.

A taxonomic study of some red algae commonly growing on the coast of Karachi

Eighteen commonly occurring species of marine benthic red algae, i.e., Asparagopsis taxiformis (Delile) Trevisan, Bangia atropurpurea (Roth) C. Agardh, Centroceras clavulatum (C. Agardh) Montagne, Calliblepharis fimbriata (Greville) Kiitzing, Coelarthrum muelleri (Sonder) B¢rgesen, Cottoniella filamentosa (Howe) B¢rgesen, Gracilariafoliifera (Forsskai) B¢rgesen, Halymenia porphyraeformis (B¢rgesen) Parkinson, Hypnea muscifor:mis (Wulfen) Lamouroux, Hypnea valentiae (Turner) Montagne, Laurencia obtusa (Hudson) Lamouroux, Me!anothamnus somalensis Bomet et Falkenberg, Porphyra vietnamensis Tanaka et Pham-hoang H6, Sarconema filiforme (Sonder) Kylin, Sebdenia flabellata (J. Agardh) Parkinson, Scinaia fascicularis (B¢rgesen) Huisman, Scinaia hatei B¢rgesen, and Solieria robusta (Greville) Kylin were collected from coastal areas near Karachi (Pakistan) and taxonomically investigated. All the investigated seaweeds are taxonomically known species. During this study, Melanothamnus somalensis is reported for the first time from northern Arabian Sea and Asparagopsis taxiformis, Bangia atropurpurea, Cottoniella filamentosa, Gracilaria foliifera, Halymenia porphyraeformis, Melanothamnus somalensis, Sarconema filiforme, Sebdenia flabellata, Scinaia fascicularis, and Solieria robusta are taxonomically described for the first time from the coast of Pakistan.

Shelf life of dried products from small indigenous fish species under various packing and storage conditions

The overall quality of five SIS products was found in good condition up to 2 months storage on the basis of organoleptic, biochemical and bacteriological characteristics and all the products was excellent in sealed packed condition up to 45 days of storage. However, quality of the products stored in open air atmospheric temperature was found excellent for first 15 days. In an average the initial moisture content was in the range of 13.5 to 15.0% with highest moisture content in puti and lowest in chapila. At the end of the 60 days the moisture content reached to the range of 18.5 to 19.0% which was more or less near the recommended limit of 16% for dried fishery products. The moisture content beyond the recommended limit as the storage period increased further and at the end of 90 days the moisture content increased to the range of 22.9 to 24% when organoleptically the product quality became very poor. The changes in the value of total volatile base nitrogen (TVB-N), peroxide value (PO), moisture and aerobic plate count (APC) of solar tunnel dried products in sealed polythene packages were investigated during 60 days of storage. There was little or no differences in TVB-N, PO and bacterial load of each species packed under various polythene density. The initial TVB-N values were in the range of 10.30 to 12.40 mg/100g of the samples. TVB-N value increased slowly up to the end of the storage period and was to in the range of 46.20 to 57.00 mg/1 00 g of sample. Initially the peroxide values (P.O.) were in the range of 6.54 to 8.40 m.eq./kg oil of the samples. During 60 days of storage, P.O. values increased slowly and at the end of the storage period these values reached to the range of 22.00 to 25.30meq./kg of sample. The initial APC was in the range 5.3xl04-7.3x104 CFU/g. The bacterial load increased slowly and at the end of the 60 days storage period reached to the range 6.6x106 - 8.6x107 CFT/g.

Shelf-life of horse mackerel fish balls stored at 0-2°C

The shelf-life of standardized horse mackerel fish balls was assessed by biochemical, microbiological, organoleptic and other spoilage changes at 0-2°C. There was decrease in pH value, moisture and the organoleptic scores. Expressible water percentage, TMA-N, TVB-N and peroxide value showed increasing trends. Total plate count also increased gradually during storage. Water separation in the treated sample was observed after 12 days and slimy consistency was noticed in the control sample on the 24th day. Based on these observations, it can be concluded that fish balls can be stored at 0-2°C for 20 days.

Utilization of trash fish for human consumption. 3: Studies on the development of fish pickle from Nemipterus japonicus

A method for the preparation of fish pickles from a lean variety of fish namely pink perch (Nemipterus japonicus) is described. Dipping the fish in 10% sodium chloride solution containing 6% acetic acid before pickling, was found desirable for retaining the meaty texture of the product. The product has no fish smell or flavour and has a shelf life of more than six months at ambient temperatures and scored very well in organoleptic tests.

Studies on radiation pasteurisation of medium fatty fish 3. Storage properties of white pomfret (Stromateus cinereus) fillets

White pomfret fillets packed under aerobic conditions had a limited shelf life of 8 days as against 10 days for samples packed under vacuum and stored at 0-2°C. Irradiation and subsequent storage of the fillets under vacuum at 0-2°C exhibited shelf lives of 30, 50 and 60 days for radiation doses of 0.1, 0.3 and 0.5 Mrad respectively in contrast to aerobically packed fillets which showed only 20, 35 and 50 days of storage life for the same levels of radiation doses and developed yellow discolouration and rancid odours.

Studies on the effect of leaching on the quality of ice-stored fish

A comparative ice storage study of milk fish (Chanos chanos) in direct contact and out of contact (in 200 gauge polyethylene bag) with ice was taken up to assess the effect of leaching on quality of ice-stored fish. It was observed that the leaching effect was more significant on TVN and NPN than that on cc amino nitrogen components while there was very little effect on bacterial load. It is concluded that under similar conditions of icing, fish out of contact with ice will have longer shelf life and more acceptability than the fish preserved in contact with ice.

The effect of washing on the quality of minced catfish during frozen storage

The effect of washing minced catfish in water, sodium chloride solution (1%) and ascorbic acid solution (0.1%) in improving the quality and frozen shelf-life has been studied. Washing improved the colour and reduced the non-protein nitrogen contents and extractable nitrogen. Denaturation was more in samples washed in salt and ascorbic acid solutions. Rancidity as measured by PV and organoleptic studies showed significant reduction in washed samples. The frozen storage life was significantly enhanced by washing.

On the occurrence of mature penaeid prawn Penaeus merguensis in a shallow solar salt works reservoir along the Okhamandal Coast of Gulf of Kutch and its spawning in laboratory

Penaeus merguensis is so far reported to attain complete maturity and spawn in the sea or deep culture ponds only. Mature specimens of stage III to V collected from a shallow reservoir of solar saltworks were studied and spawned in laboratory. A comparison of spawning of spawner from sea and reservoir is also reported.

Studies on frozen characteristics of individually quick frozen and block frozen mackerel

Studies on mackerel (Rastrelliger kanagurta) of medium (4%) and high (11%) lipid contents quick frozen individually (IQF) and as blocks (BF) and stored at -23°C showed that block frozen mackerel had higher frozen storage shelf-life than individually quick frozen samples. IQF samples of medium and high lipid contents had shelf-lives of 17 and 20 weeks whereas BF samples of both series had 23 and 24 weeks respectively based on sensory evaluation.

Shelf-life of rotary and solar tunnel dried SIS products under different packaging and storage conditions

A study was conducted on the shelf-life of rotary and solar tunnel dried SIS products under different packaging and storage conditions. Organoleptically dried products were found in good condition after a storage period of 60 days in ambient and chilled conditions. The moisture content, TVB-N value and bacterial load slightly increased during 60 days of storage in ambient and chilled conditions. The changes in moisture content and bacterial load were faster in ambient temperature than in chilled storage condition whereas changes in TVB-N value was higher in chilled condition than in ambient temperature. The initial moisture content was in the range of 13.71% to 22.84%. After 60 days of storage in ambient and chilled condition the moisture content of dried products was in the range of 15.09% to 25.11% and 14.49% to 25.01%, respectively. The initial TVB-N value was in the range of 10.64 to 17.52 mg/100g and after 60 days of storage in ambient and chilled condition, TVB-N value was in the range of 29.00 to 34.82 mg/100g and 31.41 to 39.11 mg/100g, respectively. The initial bacterial load was in the range of 1.91x10 super(8) to 2.84x10 super(8) and after 60 days of storage in ambient and chilled condition, the bacterial load was in the range of 6.2x10 super(8) to 1.8x10 super(9) and 5.75x10 super(7) to 5.05x10 super(8) CFU/g, respectively. The results of the present study indicated that it is necessary to store high quality dried products in sealed packed in chilled condition to ensure good quality up to a certain period of time.

Effect of delayed icing on the quality of tiger shrimp (Penaeus monodon Fab.)

Effect of delayed icing on the quality of Penaeus monodon iced after three hours of harvest was studied in plastic and bamboo baskets. After harvest of three hours at ambient temperature (28°-32°C), ice was added to the shrimp at a ratio of 1:1 (shrimp:ice) and stored for 21 hours in both the baskets. Quality evaluation was carried out through visual assessment, biochemical analysis and microbial analysis for 24 hours. The organoleptic evaluation and scoring was done from the time of harvest treated as 0 hour and the average score was 10. At 9th hour after iced condition quality of shrimp was found reduced to the next stage (acceptable) with a score ranged from 8.4-6.5 in both baskets. This acceptable stage was observed throughout the experiment for bamboo basket whereas in the plastic basket the quality was reduced to a small extent with a score of 6.4 (moderately acceptable). Till the end point of the experiment the quality of shrimp was acceptable in respect to biochemical analysis. The microbial load was found log sub(10) 3.99±0.12 cfu/g to log sub(10) 4.33±0.21 cfu/g and log sub(10) 4.01 ±0.12 cfu/g to log sub(10) 4.83±0.19 cfu/g in the bamboo and plastic basket respectively. The importers or buyers suggests for immediate icing to maintain good quality but results of the present experiment suggest that the quality does not vary drastically for first three hours.

The effect of Rosmarinus officinalis and Zataria multiflora extracts on the stability of poly unsaturated fatty acids in frozen silver carp minced

The purpose of this study, Evaluation the effect of Rosmarinus officinalis and Thymus vulgaris extracts on the stability of poly unsaturated fatty acids in frozen Silver carp minced. Treatments include: Treatment 1 - Control: frozen meat packaged in conventional Treatment 2: Frozen Silver carp minced+Thyme 300 mg/kg in normal packaging Treatment 3: Frozen Silver carp minced+Rosemary 200 mg/kg in normal packaging Treatment 4: Frozen Silver carp minced+Rosemary compound (100 mg/kg) and Thyme (100 mg/kg) in normal packaging After rapid freezing of samples in the spiral freezer by individual quick freezing method, to maintain the cold temperature (-18) °C were transferred. Sampling and measurements to determine the fatty acid profile of the zero phase beginning in the first month and then every ten days, and 15 days in the second month of the third month after the monthly test. Identifying, defining and measuring the fatty acid profile by gas chromatography was performed. In this study, levels of both saturated and unsaturated fatty acids in three experimental and one control were identified as follows: A: saturated fatty acids: Meristic C14: 0/Palmitic C16: 0/Hepta decaenoic C17: 0/Stearic C18: 0/Arashidic C20: 0/B:Mono unsaturated fatty acids: palmitoleic C16: 1-W7/Oleic C18: 1-W9/Gadoleic C20: 1-W9 C:Poly unsaturated fatty acids: Linoleic C18: 2-W6/α-Linolenic C18: 3-W3 D:High unsaturated fatty acids: Arachidonic C20: 4-W6 Eicosapentaenoic acid C20: 5-EPA/W3 Docosahexaenoic C22: 6-DHA/W3 Results of this study was to determine, Thyme and rosemary extracts containing silver carp minced stored in freezing conditions, Stability of different types of fatty acids, monounsaturated fatty acids, poly-unsaturated fatty acids, omega-3 and omega-6 fatty acids are. So that none of the fatty acids measured were not significant 100% increase or decrease, While changes in the fatty acid oxidation during storage time is minimized. The results obtained from the fatty acid profiles and indicators of their and statistical tests show that treatment with rosemary extract More stable during storage (-18) ° C In comparison with the control and other treatments are shown; And at relatively low compared to other treatments and control samples oleic acid and linoleic acid, palmitic more. According to studies,in Silver carp minced that containing rosemary extract, end of the storage period of six months. Were usable, so even rosemary extract the shelf-life examples to increase more than six months.