996 resultados para Shrimp fisheries
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Packaging is important not only in extending the shellife of fish and fishery products but also improving their marketability. In the recent years, significant development have taken place in the packaging industry. During the past decade in India, there is almost a packaging revolution with the availability of variety packaging materials, thus generating better packaging consciousness in other producer/manufacturing industries. But unfortunately, such realisation is not forthcoming in the fisheries sector and packaging techniques for local and export trade continues to be on traditional lines with their inherent drawbacks and limitations. Better packaging ensures improved quality and presentation of the products and ensures higher returns to the producer. Among several packaging materials used in fishery industry, ISI specifications had been formulated only for corrugated fibre board boxes for export of seafoods and froglegs. This standard was formulated before containersiation came into existance in the export of marine products. Before containerisation, the standards were stringent in view of the rough handling, transportation and storage. Two of the common defects reported in the master cartons exported from India are low mechanical strength and tendency to get wet. They are weakened by the deposits of moisture caused by temperature fluctuations during loading, unloading and other handling stages. It is necessary to rectify the above defects in packaging aquatic products and hence in the present study extensive investigations are carried out to find out the reasons for the damage of master cartons, to evolve code of practice for the packaging oi frozen shrimp for exports, development of alternative style of packaging for the shipping container, development of suitable consumer packaging materials for fish soup powder, cured dried mackeral, fish pickles in oil and frozen shrimp. For the development of suitable packaging materials, it is absolutely essential to know the properties of packaging materials, effect of different packaging materials on theirshelf life and their suitability for food contact applications.
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A general introduction to the problems faced in the shrimp culture due to waste formation and its consequent environmental hazards and production problems of Giant tiger shrimp, Penaeus monodon is highlighted by the author in this thesis. The objective of the present work was to assess the potential of brackish water finfish to improve bottom soil conditions and thereby increase the growth and production of Penaeus monodon. The salient findings of the present study are summarized in chapter 7. This is followed by the references cited in the thesis and list ofpublications originated from the present study.
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Penaeid shrimps are, perhaps, the most important fishery resource of the coastal waters of our country. Their exceptionally tasty. protein-rich flesh tops any seafood in foreign exchange earnings. No wonder, the demand of shrimp, the "Pinkish Gold of the Sea" (MPEDA. 1992). is increasing in the world market. The study of the growth of an organism is important in understanding the conditions under which optimum growth occurs. It is also important in getting an insight into the various factors that influence growth. Studies on the growth pattern of commercially important species of shrimp and of the factors that influence their growth rate are essential for the successful cultivation of shrimps.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Population parameters of the shrimp Xiphopenaeus kroyeri (Heller, 1862) (sex ratio, length-frequency distributions (carapace length, CL), growth, lifespan, size of sexual maturity, spawning and recruitment) were analyzed in a long-term study from January 1998 through June 2003. The data on these parameters were collected and analyzed to test the hypothesis that the main period of juvenile recruitment in the bay coincides with the period of fishery closures currently designated by the Brazilian Institute of Environment and Renewable Natural Resources. Monthly collections were conducted along the southeastern Brazilian coast, using a shrimp fishing boat with “double-rig” nets sampling at stations up to 40 m depth. Sex ratios were female-biased only in zones with high reproductive activity such as in stations deeper than 15 m (χ2 test, p<0.05). The mean size of males and females was 15.3 ± 3.1 mm CL and 16.2 ± 4.7 mm CL, respectively, with size at sexual maturity estimates (CL50) of 14.8 mm for males and 15.5 mm for females. Mean growth curves provided estimates of CL∞ = 29.31 mm, k = 0.009/day, t0=−0.25 and CL∞ = 35.33 mm, k = 0.006/day, t0=−0.23 for males and females, respectively, and average lifespans of 1.35 for males and 2.12 years for females. Recruitment and abundances of reproductive females were highly correlated with the environmental factors such as higher water temperature and finer-grained bottom sediment (canonical correlation, r=0.63, p<0.001). The reproductive peaks in February-April 1998, March-May 1999 and February-May 2002 were followed by recruitment peaks in May-July 1998, July-September 1999 and April-June 2002, respectively. Thus, the proposed period of fisheries closure (March to May) does not coincide with the main recruitment periods observed for X. kroyeri.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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In southeastern Brazil, slipper lobsters (Scyllarides deceptor and S. brasiliensis) are caught by fleets trawling for pink shrimp (Farfantepenaeus brasiliensis and F. paulensis) and pots-and-traps fishing for octopuses (Octopus vulgaris). Eight hundred fifty-six landings of shrimp trawlers and 28 of the octopus fleet were monitored in the Santos region from May 2006 to April 2007. Additional analysis was performed using a database covering the period from 1999 onwards. This study seeks to identify the recent patterns of exploitation of these lobsters with the goal of improving the way towards fishery sustainability. Scyllarides deceptor was the dominant lobster species with 1032 specimens collected, while only three specimens of S. brasiliensis were identified. The area known as the `Farol do Boi` (23 degrees 01`S, 45 degrees 00`W to 25 degrees 00`S, 45 degrees 40`W at 60-135 m deep) showed the highest Catch Per Unit Effort (CPUE). A General Linearized Model (GLM) was used to investigate the factors influencing variations in CPUE in trawl fleets and led to the conclusion that year, month and depth were the most important factors. We detected a significant decrease in the relative abundance of lobsters in the fishing zone despite relatively low fishing effort. Recommendations to protect the lobster resources include taking special precautions in the natural refuge area of the `Farol do Boi`, as an exclusion zone for trawl fleets, and controlling the use of traps longlines to catch octopuses. Concerns about depensatory processes due to the over-exploitation of lobster populations around the world are raised. (C) 2009 Elsevier B.V. All rights reserved.
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Aquafeed production faces global issues related to availability of feed ingredients. Feed manufacturers require greater flexibility in order to develop nutritional and cost-effective formulations that take into account nutrient content and availability of ingredients. The search for appropriate ingredients requires detailed screening of their potential nutritional value and variability at the industrial level. In vitro digestion of feedstuffs by enzymes extracted from the target species has been correlated with apparent protein digestibility (APD) in fish and shrimp species. The present study verified the relationship between APD and in vitro degree of protein hydrolysis (DH) with Litopenaeus vannamei hepatopancreas enzymes in several different ingredients (n = 26): blood meals, casein, corn gluten meal, crab meal, distiller`s dried grains with solubles, feather meal, fish meals, gelatin, krill meals, poultry by-product meal, soybean meals, squid meals and wheat gluten. The relationship between APD and DH was further verified in diets formulated with these ingredients at 30% inclusion into a reference diet. APD was determined in vivo (30.1 +/- 0.5 degrees C, 32.2 +/- 0.4%.) with juvenile L vannamei (9 to 12 g) after placement of test ingredients into a reference diet (35 g kg(-1) CP: 8.03 g kg(-1) lipid; 2.01 kcal g(-1)) with chromic oxide as the inert marker. In vitro DH was assessed in ingredients and diets with standardized hepatopancreas enzymes extracted from pond-reared shrimp. The DH of ingredients was determined under different assay conditions to check for the most suitable in vitro protocol for APD prediction: different batches of enzyme extracts (HPf5 or HPf6), temperatures (25 or 30 degrees C) and enzyme activity (azocasein): crude protein ratios (4 U: 80 mg CP or 4 U: 40 mg CP). DH was not affected by ingredient proximate composition. APD was significantly correlated to DH in regressions considering either ingredients or diets. The relationships between APD and DH of the ingredients could be suitably adjusted to a Rational Function (y = (a + bx)/(1 + cx + dx2), n = 26. Best in vitro APD predictions were obtained at 25 degrees C, 4 U: 80 mg CP both for ingredients (R(2) = 0.86: P = 0.001) and test diets (R(2) = 0.96; P = 0.007). The regression model including all 26 ingredients generated higher prediction residuals (i.e., predicted APD - determined APD) for corn gluten meal, feather meal. poultry by-product meal and krill flour. The remaining test ingredients presented mean prediction residuals of 3.5 points. A model including only ingredients with APD>80% showed higher prediction precision (R(2) = 0.98: P = 0.000004; n = 20) with average residual of 1.8 points. Predictive models including only ingredients from the same origin (e.g., marine-based, R(2) = 0.98; P = 0.033) also displayed low residuals. Since in vitro techniques have been usually validated through regressions against in vivo APD, the DH predictive capacity may depend on the consistency of the in vivo methodology. Regressions between APD and DH suggested a close relationship between peptide bond breakage by hepatopancreas digestive proteases and the apparent nitrogen assimilation in shrimp, and this may be a useful tool to provide rapid nutritional information. (C) 2009 Elsevier B.V. All rights reserved.
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Proteases from the midgut gland of the Farfantepenaeus paulensis juveniles were assessed. Enzyme activity was determined using protease substrates and inhibitors. The effect of pH, temperature and calcium on proteolytic activity was assayed. Caseinolytic activity was analysed in substrate-sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Trypsin, chymotrypsin and leucine aminopeptidase activity was detected. Proteolytic activity was strongly inhibited by the specific trypsin inhibitors. Tosyl-phenylalanine chloromethyl ketone inhibited 59.3% of chymotrypsin activity. The greatest trypsin-like activity occurred at pH 8.0 and 45 degrees C. Chymotrypsin-like activity reached maximal values at alkaline pH (7.2-9.0) and 55 degrees C. CaCl(2) did not increase trypsin-like activity, but rather inhibited it at concentrations of 30 (20%), 50 (30%) and 100 mM (50%). The substrate-SDS-PAGE zymogram revealed eight proteinase bands. Two possibly thermal-resistant (85 degrees C, 30 min) chymotrypsin isoforms were found, which were inhibited by phenyl-methyl-sulphonyl-fluoride. Aminopeptidase activity of enzyme extracts (Arg, Leu, Lys, Phe and Val) and the recommended concentrations of these essential amino acids in penaeid shrimp diets were positively correlated (P < 0.05). Beause protein digestion involves the combined action of different enzymes, adequate knowledge of shrimp digestion and enzyme characteristics is required for the assessment of the digestive potential of different feed sources and development of in vitro digestibility protocols.
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The penaeidean Litopenaeus schmitti, popularly known as white shrimp, is a species of great economic importance, being a target of fishing fleets in the southeast region of Brazil. It is distributed through the western Atlantic, from Cuba to Brazil, until Rio Grande do Sul. Adults are found from shallow depths up to 30 m and have been found to depths of 47 m in the state of Rio de Janeiro, while juveniles are located in bays and estuaries. The studied species is seasonally distributed in the region of Ubatuba. The objectives of this study are to analyze the abundance and ecological distribution of L. schmitti and to assess if and when juveniles use the Indaia estuary during their life cycle. Furthermore, the hypothesis was tested that the main period of recruitment in the bay coincides with the period of closure of fisheries defined by the Instruction of IBAMA. To that end, samples were taken monthly from July 2005 through June 2007, both in Ubatuba Bay and in the estuary formed by the Rio Indaia. At each sampling station, salinity, temperature (bottom), depth, organic matter content (%), and grain size of sediments were measured. We found that the largest catches in the estuary were in late spring and early summer. In Ubatuba Bay, peak catches occurred during winter and early spring, whereas in the second year, already in May, there was a high peak capture. The variation in the number of individuals was correlated with some environmental factors both in the estuary and in the inlet (p < 0.05). In the estuary, abundance was positively correlated with temperature (p = 0.008) and organic matter (p = 0.025) and negatively with depth (p = 0.009). Regarding the Ubatuba Bay, only temperature (p = 0.034) and depth (p = 0.013) were significantly associated with the distribution of the shrimp, both being negative relations. The shrimp L. schmitti uses both the estuarine as well the shore environment, particularly the Ubatuba estuary and its adjacent bay, to complete its life cycle. The proposed period of fisheries closure (between March to May in the state of Sao Paulo) for this and other shrimps coincides with individuals capable of reproduction entering the inlet and thus are being protected.
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The combined effects of salinity, temperature and cadmium stress on survival and adaptation through cadmium-binding protein (CdBP) accumulation were studied in the grass shrimp, Palaemonetes pugio. In 96-hour bioassays, shrimp were exposed to zero or one of three levels of cadmium, under one of six different salinity (15, 25, or 35$\perthous$) and temperature (20 or 30$\sp\circ$C) regimes. CdBP concentrations were quantified in survivors from the 24 exposure groups. Salinity and temperature did not affect survivorship unless the shrimp were also exposed to cadmium. Grass shrimp were most sensitive to cadmium at low salinity-high temperature, and least sensitive at high salinity-low temperature. The incidence of cadmium-associated black lesions in gill tissue was influenced by salinity and temperature stress. P. pugio produced a 10,000 dalton metallothionein-like CdBP when exposed to at least 0.1 mg Cd$\sp{2+}$/L for 96 hours. Accumulation of CdBP was increased with increases in the exposure cadmium level, increases in temperature and decreases in salinity, independently and in conjunction with one another. Maximum CdBP concentrations occurred in grass shrimp that survived the salinity-temperature-cadmium conditions creating maximum stress as measured by highest mortality, not necessarily in shrimp exposed to the highest cadmium levels. The potential utility of this method as a monitor of physiological stress in estuarine biota inhabiting metal-polluted environments is discussed. ^
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A preliminary field survey was conducted to determine the distribution of ectosymbiotic shrimp Periclimenes holthuisi on the sea anemone Stichodactyla haddoni in Moreton Bay (Queensland, Australia). Laboratory experiments were also carried out to verify whether the shrimp show a preference for one anemone host. In the field, 45 individuals of P. holthuisi were found to be associated with 70% of the specimens of S. haddoni (n=20). We inferred this shrimp population was not space-limited because not all anemones were colonized. After having been isolated from their natural host for 2 weeks, when placed between individuals of S. haddoni and Macrodactyla doreensis (an anemone that is sympatric with S. haddoni), shrimp overwhelmingly selected S. haddoni (92%). To establish whether M. doreensis may serve as an alternative host for P. holthuisi, unacclimated shrimp were forced to associate with this anemone. Macrodactyla doreensis showed little tentacle reaction during this association; shrimp were found on the anemone's tentacles and the column. The finding that M. doreensis can serve as an alternative host for P. holthuisi demonstrates that this anemoneshrimp is adaptable to another anemone host and thus may not be highly host specific.