ABSTRACT
India being endowed with a vast coastline, has been a successful producer of Aqua culture products and is a competitive supplier of shrimps. Andhra Pradesh emerged as leading producer of this species. However, due to unsustainable farming practices many ponds have become unit for Shrimp culture. Poor farming practices has greatly affected the quality of the environment and this in turn has to led to large scale abandonment of shrimp farms. Further, the abandonment of existing farms has resulted in conversion of agricultural lands and mangroves to new shrimp ponds. The primary objective of this paper is to study the shrimp farming practices of the farmers, understand the challenges faced by the shrimp farmers and explore the underlying causes for abandonment of ponds. The study is based on a focus group discussion conducted among few farmers who have been practicing Shrimp culture near the Kandaleru Creek of Nellore district in Andhra Pradesh. Abandonment of shrimp ponds and conversion of mangroves into new shrimp ponds for culture affects the environmental sustainability and future prospects of the shrimp industry. Further the study also attempts to identify development strategies that could be implemented to revive the existing ponds for practice of sustainable shrimp culture.
ABSTRACT
Shrimp aquaculture industry is facing diseases problems, viral and bacterial pathogens that take advantage of theweak immunity of shrimp and an altered gut microbial community. Furthermore, probiotic practices in aquaculturestarted to be of importance for increased disease resistant, aquatic organisms growth, and feed efficiency. Later theyare used to improve the water quality of bacterial infections. Today, there is an evidence that probiotics can improvethe digestibility of nutrients, increase tolerance to stress, and encourage reproduction. They are substances containinglive microorganisms secreted by microorganisms that stimulate the growth of other organisms. At presently, manycommercial probiotic products made by bacterial species such as Lactobacillus sp., Bacillus sp., Carnobacterium sp.,Enterococcus sp., and also from yeast, i.e., Saccharomyces cerevisiae are available. This review article gives a briefexplanation on probiotics, their types, origin, mode of action, types of diseases they can control, ability to improvenutrients digestion, increase stress tolerance, and increase of reproduction.
ABSTRACT
It is generally believed that increasing feeding frequency has immediate benefits, including reduced nutrient leaching and increased shrimp growth. In this context, the aim this work was to evaluate the effect of feeding frequency in growth performance of Farfantepenaeus paulensis. Juveniles of Farfantepenaeus paulensis were grown for 30 days in pen enclosures, at a stocking density of 5 shrimp/m2. The shrimp were fed on feeding trays at a rate of 8% of their biomass per day, with treatments of one, two, three and four times per day, with four replicates each. The results showed no differences (5% probability) in biomass gain of F. paulensis when feed was offered two, three or four times per day. However, it was observed that the once a day frequency had a negative influence on weight gain for this species of shrimp. We conclude that the supply of food with 35% crude protein twice a day is sufficient for the growth of F paulensis. Feeding frequency of three or four times can provide increased spending in the cultivation of juveniles of this species.
Acredita-se que uma frequência maior de alimentação traz benefícios imediatos, incluindo a redução da lixiviação de nutrientes e o aumento do crescimento do camarão. Nesse contexto, o objetivo do presente trabalho foi avaliar o efeito de diferentes frequências de oferta de alimento sobre o crescimento de Farfantepenaeus paulensis. Juvenis de Farfantepenaeus paulensis foram criados por 30 dias em tanques-rede, na densidade de estocagem de cinco camarões/m 2. Os camarões foram alimentados em comedouros com 8% da sua biomassa/dia, ofertados em parcelamentos de uma, duas, três e quatro vezes ao dia, com quatro repetições para cada tratamento. Os resultados mostraram que não ocorreram diferenças (5% de probabilidade) no ganho de biomassa de F. paulensis quando a frequência alimentar foi de duas, três ou quatro vezes ao dia. No entanto, os dados indicam que a frequência alimentar de uma vez ao dia interferiu negativamente no ganho de peso dessa espécie. Conclui-se que o fornecimento de ração com 35% de proteína bruta duas vezes ao dia é suficiente para o crescimento de F paulensis. O fornecimento de alimento três ou quatro vezes ao dia poderia acarretar maiores gastos no manejo de juvenis dessa espécie.
Subject(s)
Animals , Animal Feed , Artemia , Feeding Behavior , Aquaculture , Weight GainABSTRACT
The sodium metabisulphite (SMB) is used in shrimp farming to prevent melanosis and the 5.0 ppm chlorine (CL) concentration used in the shrimp processing is efficient as a bactericide, but there is no evidence of the effectiveness of these chemical compounds as fungicides. Therefore, the aim of this study was to evaluate the in vitro effect of sodium metabisulphite (SMB) and chlorine (CL) on the growth of Aspergillus and Penicillium species isolated from marine shrimp in different stages of processing. The samples were collected from a frozen shrimp processing industry, located in Piauí State, Brazil. The total fungi and occurrence of Aspergillus and Penicillium species were evaluated. For in vitro sensibility test using the diffusion disk in agar method, five concentrations of SMB (0%, 1%, 3%, 5% and 10%) and six of CL (0, 1, 2, 3, 4 and 5 µg mL-1) were used. The fungal counts in the different processing stages ranged from 1.74 to 3.38 CFU g-1. Twenty-nine Aspergillus strains were isolated, prevailing A. versicolor (59.3%) and twenty-two of Penicillium, prevailing P. citrinum (74%). One strain of A. flavus was AFB1 producer. All the isolated strains of P. citrinum produced citrinin. All tested species were in vitro sensitive to 3% of SMB, except the A. flavus. The 10% concentration of SMB inhibited the in vitro growth of all strains. The CL concentrations tested did not inhibit the studied species growth and SMB concentrations above 3.0% inhibited in vitro the growth of the tested strains.
O metabissulfito de sódio (SMB) é usado na carcinicultura para evitar a melanose e a concentração de 5,0ppm de cloro (CL), utilizada no beneficiamento do camarão, é eficiente como bactericida, porém não há comprovação da eficácia destes compostos químicos como fungicida. Desse modo, o objetivo deste estudo foi avaliar o efeito in vitro do metabissulfito de sódio (SMB) e cloro (CL) sobre o crescimento de espécies de Aspergillus e Penicillium isolados de camarão marinho em diferentes estágios de processamento. As amostras foram coletadas de uma indústria de processamento de camarão congelado, localizada no Estado do Piauí, Brasil. Fungos totais e ocorrência das espécies de Aspergillus e Penicillium foram avaliados. Para o teste in vitro de sensibilidade pelo método disco-difusão em ágar, foram utilizadas cinco concentrações de SMB (0%, 1%, 3%, 5% e 10%) e seis de CL (0, 1, 2, 3, 4 e 5µg mL-1). As contagens fúngicas nos diferentes estágios de processamento variaram de 1,74 a 3,38UFC g-1. Foram isoladas 29 cepas de Aspergillus, prevalecendo o A. versicolor (59,3%) e 22 de Penicillium, prevalecendo o P. citrinum (74%). Uma cepa de A. flavus era produtora de AFB1. Todas as cepas de P. citrinum isoladas produziram citrinina. Todas as espécies testadas foram sensíveis in vitro a 3% do SMB, com exceção do A. flavus. A concentração de 10% do SMB inibiu in vitro o crescimento de todas as cepas. As concentrações de CL testadas não inibiram o crescimento das espécies isoladas e concentrações de SMB acima de 3,0% inibiram in vitro o crescimento das linhagens testadas.
ABSTRACT
Este estudo avaliou o desempenho zootécnico do camarão marinho Litopenaeus vannamei em diferentes tipos de substratos não consolidados. Juvenis (0,97 ± 0,27 g) foram aclimatados na densidade de 52 m-2, em 21 caixas de polietileno com biofiltros individuais, em um sistema fechado de filtração contínua, sendo submetidos aos tratamentos: 1) A = 25% silte + 25% argila + 25% areia muito fina + 25% areia fina; 2) B = 50% areia fina + 50% areia muito fina e 3) Controle = sem substrato, em um delineamento experimental completamente casualizado, com três tratamentos e sete repetições cada. Os animais foram alimentados com 12% da biomassa/dia com ração peletizada (35% de proteína bruta), ofertada em bandejas e parcelada em duas ofertas diárias (8 e 16h). O estudo teve duração de 48 dias, sendo avaliados: consumo aparente de ração, eficiência alimentar, taxa de crescimento específico, sobrevivência e ganho de peso. Foram acompanhados diariamente salinidade, pH, amônia e temperatura da água. A análise estatística dos dados se deu por meio dos testes Anova ou Kuskal-Wallis, em função da sua parametricidade. Não foram observadas diferenças significativas com relação aos fatores avaliados nas diferentes granulometrias de sedimento testadas, indicando que estas não exerceram influência sobre o desempenho zootécnico de L. vannamei juvenil.
This study aimed to evaluate the zootechnical performance of Litopenaeus vannamei shrimp at different types of unconsolidated substrate. Juvenile shrimp (0.97 ± 0.27 g) were acclimatized, in a stocking density of 52 m-2, to 21 polyethylene boxes (50 L) connected individually to biofilters in a closed water exchange system. The animals were submitted to the treatments: 1) A = 25% silt + 25% clay + 25% very fine sand + 25% fine sand; 2) B = 50% fine sand + 50% very fine sand and 3) Control = no sediment, with seven replications each. Photoperiod was set on 12L: 12D. Shrimps were fed twice a day (at 08:00 and 16:00h) with 12% total biomass day-1. Food was offered in feeding trays 2 cm from the substrate. The experiment had a duration of 48 days, evaluating: apparent ration intake, food efficiency, specific growth rate, survival and weight gain. During this period, water quality was monitored daily. Data was analyzed by Anova or Kuskal-Wallis test, depending on normality (SigmaStat 3.1, 2004 and STATISTICA 6.0, 2001). There were no differences among groups regarding weight gain, food intake, SGR and survival, indicating that these did not exert influence on the zootechnical performance of L. vannamei juvenil.
Subject(s)
Animals , Substrates for Biological Treatment , Aquaculture , EthologyABSTRACT
This study aimed to evaluate the zootechnical performance of Litopenaeus vannamei shrimp at different types of unconsolidated substrate. Juvenile shrimp (0.97 ± 0.27 g) were acclimatized, in a stocking density of 52 m-2, to 21 polyethylene boxes (50 L) connected individually to biofilters in a closed water exchange system. The animals were submitted to the treatments: 1) A = 25% silt + 25% clay + 25% very fine sand + 25% fine sand; 2) B = 50% fine sand + 50% very fine sand and 3) Control = no sediment, with seven replications each. Photoperiod was set on 12L: 12D. Shrimps were fed twice a day (at 08:00 and 16:00h) with 12% total biomass day-1. Food was offered in feeding trays 2 cm from the substrate. The experiment had a duration of 48 days, evaluating: apparent ration intake, food efficiency, specific growth rate, survival and weight gain. During this period, water quality was monitored daily. Data was analyzed by Anova or Kuskal-Wallis test, depending on normality (SigmaStat 3.1, 2004 and STATISTICA 6.0, 2001). There were no differences among groups regarding weight gain, food intake, SGR and survival, indicating that these did not exert influence on the zootechnical performance of L. vannamei juvenil.
Este estudo avaliou o desempenho zootécnico do camarão marinho Litopenaeus vannamei em diferentes tipos de substratos não consolidados. Juvenis (0,97 ± 0,27 g) foram aclimatados na densidade de 52 m-2, em 21 caixas de polietileno com biofiltros individuais, em um sistema fechado de filtração contínua, sendo submetidos aos tratamentos: 1) A = 25% silte + 25% argila + 25% areia muito fina + 25% areia fina; 2) B = 50% areia fina + 50% areia muito fina e 3) Controle = sem substrato, em um delineamento experimental completamente casualizado, com três tratamentos e sete repetições cada. Os animais foram alimentados com 12% da biomassa/dia com ração peletizada (35% de proteína bruta), ofertada em bandejas e parcelada em duas ofertas diárias (8 e 16h). O estudo teve duração de 48 dias, sendo avaliados: consumo aparente de ração, eficiência alimentar, taxa de crescimento específico, sobrevivência e ganho de peso. Foram acompanhados diariamente salinidade, pH, amônia e temperatura da água. A análise estatística dos dados se deu por meio dos testes Anova ou Kuskal-Wallis, em função da sua parametricidade. Não foram observadas diferenças significativas com relação aos fatores avaliados nas diferentes granulometrias de sedimento testadas, indicando que estas não exerceram influência sobre o desempenho zootécnico de L. vannamei juvenil.
ABSTRACT
This paper estimates annual P emission to the Jaguaribe River estuary, NE Brazil, responsible for approximately 30 percent of the country's farmed shrimp production. Emissions increased three times between 2001 and 2006 and reached 43.9 t.year-1. These emissions make aquaculture the third main source of P for this estuary and are much smaller than emissions from agricultural sources and slightly lower than emissions from wastewater. Their relative contribution also increased from 10.5 percent to 20.5 percent. Temporal variability of P concentrations in estuarine bottom sediments also suggest an increase, but not as evident as the emissions. The spatial distribution and speciation of P (total P and inorganic P) in sampling stations located upstream and downstream from the main aquaculture area confirmed the importance of this source. Inorganic P was the dominant form present in sediments downstream and showed an increase from 67 percent to 75 percent of the total P present in the sediment.
É apresentada uma estimativa da emissão anual de P para o estuário do rio Jaguaribe, Ceará, Nordeste do Brasil, área responsável por cerca de 30 por cento da produção total de camarão cultivado no país. As emissões aumentaram por um fator de três entre 2001 e 2006, atingindo 43,9 t.year-1. Essa emissão coloca a aquacultura como a terceira fonte principal de P para esse estuário, sendo bem menor que a emissão de fontes agrícolas e um pouco menor que as emissões por águas servidas. A contribuição relativa da aquacultura também aumentou de 10,5 por cento a 20,5 por cento, no mesmo período. A variação temporal das concentrações de P em sedimentos estuarinos sugere um aumento no período, porém não tão evidente quanto das emissões. A distribuição espacial e a especiação do P (P total e P inorgânico) em estações de coleta localizadas à montante e à jusante da principal área de aquacultura confirmaram a importância desta fonte. O P inorgânico foi a forma dominante presente em sedimentos à jusante e mostrou um aumento de 67 por cento a 75 por cento do total de P presente no sedimento.
Subject(s)
Animals , Environmental Monitoring/methods , Geologic Sediments/chemistry , Phosphorus/analysis , Rivers/chemistry , Water Pollutants, Chemical/analysis , Aquaculture , BrazilABSTRACT
This study compares water quality parameters, shrimp growth and mortality rates, and biomass at harvest in two ponds of equal size, seeded with the same density (7 m-2) of White Spot Syndrome Virus (WSSV) and Monodon Baculo Virus (MBV) negative post-larvae (PL)-20 of shrimp, Penaeus monodon in the Vellar estuary of South India. The primary difference between the ponds was the water source; one was filled from the estuary and the second with water from bore wells with high alkalinity. Temperature in both ponds was similar and reached 32oC after 185 days of culture. Dissolved oxygen (DO) levels were within the acceptable range although levels in the alkaline pond were near the lower limit for the last 90 days before harvest. Salinity levels were similar in both ponds, above optimal levels, and increased over the 185 days. Alkalinity in the estuarine water was typically < 50 ppm and again 200-320 ppm in the alkaline pond. In the alkaline pond, beginning on the 75th day mineral deposits was observed covering all parts of the shrimp including the eye and the inner gill chambers, and by harvest, 42% of the shrimp showed this coating. Elemental analysis identified the major constituents as calcium, phosphorus and manganese. Survival rates in the estuarine-water-fed pond was 92% with a total pond biomass at harvest of 1.65 tons ha-1 compared to survival of 79% in the alkaline pond and a biomass at harvest of 1.020 tons ha-1. When well water must be used, its alkalinity should be monitored and diluted with water from other sources.
ABSTRACT
The objective of this study was to determine the LC50 (96h) of two pesticides: Sirius® 250 SC herbicide of the pyrazosulfuron-ethyl group, and Talcord® insecticide of the permethrin group, on juvenile Litopenaeus vannamei. Shrimp total hemocyte count (THC) was also determined as an indication of physiological alterations caused by the pesticides. Juvenile shrimp (5.0 ± 0.5 g) were exposed to the following concentrations: 0, 0.1, 1.0, 10, 100 and 1000 µg L-1 Sirius® 250 SC; and 0, 0.001, 0.01, 0.1, 1.0 and 10 µg L-1 Talcord®. The Talcord® LC50 (96h) was of 0.00933 µg L-1 or 9.33 ng L-1. There were no significant changes in the THC between control and test groups. No Sirius® 250 SC concentrations tested killed more than 50% of the shrimp; therefore, the herbicide was considered not toxic to the juveniles. However, the THC showed significant differences between the control and test groups, suggesting sublethal effects to L. vannamei juveniles. According to the results, the insecticide Talcord® is highly lethal for L. vannamei and the herbicide Sirius® 250 SC was not lethal in the concentrations tested but showed sublethal effects as lower THC. The results demonstrate the risks involved in farming L. vannamei shrimp near rice cultures where these pesticides are routinely used.
O objetivo deste trabalho foi determinar a CL50 (96h) dos agroquímicos Sirius® 250 SC, herbicida à base de pirazossulfurom-etílico, e Talcord®, inseticida à base de permethrin, em juvenis de Litopenaeus vannamei, bem como avaliar possíveis alterações fisiológicas por meio da contagem total de hemócitos (CTH) dos camarões. Juvenis de L. vannamei (5,0 ± 0,5 g) foram expostos às seguintes concentrações dos agroquímicos: Sirius® 250 SC, 0; 0,1; 1; 10; 100 e 1.000 µg L-1, e Talcord®, 0; 0,001; 0,01; 0,1; 1 e 10 µg L-1. A CL50 (96h) do inseticida Talcord® foi de 0,00933 µg L-1 ou 9,33 ng L-1. Não houve alterações significativas da CTH entre as médias dos grupos-controle e dos submetidos ao inseticida. Com base nas concentrações testadas do herbicida Sirius® 250 SC, não foi possível determinar a CL50 (96h), assim, este produto não foi considerado tóxico para os juvenis de L. vannamei. Porém, a CTH dos camarões expostos ao herbicida demonstrou diferenças significativas entre as médias do controle e dos tratamentos, o que evidenciou efeito subletal. Os resultados permitem concluir que o inseticida Talcord® é altamente letal para os juvenis de L. vannamei e o herbicida Sirius® 250 SC, apesar de não ter a mesma toxicidade, apresenta efeito subletal relacionado com a diminuição na CTH. Os resultados sugerem a existência de riscos em se cultivar L. vannamei nas proximidades de fazendas de arroz, em que defensivos agrícolas são usados rotineiramente.
Subject(s)
Pesticides , ToxicologyABSTRACT
El cultivo del camarón marino Litopenaeus vannamei (Boone, 1931) es el rubro más importante de la acuicultura venezolana. Hasta el año 2005, su producción por hectárea en Venezuela era una de las más altas en Latinoamérica. El éxito residía en parte, en la domesticación de la especie y el haber cerrado el ciclo biológico, lo cual le permitió al país mantenerse por más de dos décadas, libre de las enfermedades virales de impacto severo como Taura y Mancha Blanca. Sin embargo, en el año 2005 se confirmó la presencia del virus del Taura, que afectó un 67% del total de granjas en los estados Zulia, Falcón y Nueva Esparta. Las enfermedades han motivado a los camaronicultores a buscar alternativas, dentro de las cuales se encuentra el cultivo de camarón marino en agua dulce. Por esta razón, este trabajo tuvo como objetivo el cultivo de camarón (L. vannamei) en agua dulce en Paraguaná, estado Falcón, Venezuela. Las postlarvas (Pls), fueron sembradas en un estanque de 969 m²de superficie. Antes de iniciar el ciclo de cultivo, se analizaron muestras de agua y de los suelos para garantizar que los parámetros recomendados para el cultivo de L. vannamei en agua dulce se cumplieran. Las Pls provenientes de un programa de mejoramiento genético fueron sometidas a un período de aclimatación y adaptación al agua dulce durante 58,5 horas. Obtenida la aclimatación se procedió a la siembra de las mismas a una densidad de 42 Pls/m². Durante el cultivo se registraron los parámetros físico-químicos (oxígeno disuelto, salinidad y temperatura). La dieta de los camarones consistió en un alimento balanceado peletizado K-maron 35®. El porcentaje de supervivencia, peso promedio, crecimiento semanal promedio, talla promedio, factor de conversión alimenticia y productividad se registraron mediante muestreos mensuales. Para el análisis de datos se empleó estadística descriptiva. El cultivo tuvo una duración de 94 días y se registraron los siguientes valores de producción: 65,19% de supervivencia, 10,66 g. de peso promedio, 1,01:1 de factor de conversión alimenticia y un rendimiento de 2.579,98 kg/ha/ciclo. Los resultados demuestran la factibilidad de este tipo de cultivo como una nueva alternativa de producción acuícola para los pequeños-medianos productores en la Península de Paraguaná-Falcón, Venezuela.
Culture of L. vannamei marine shrimp is very important to Venezuelan aquaculture. Until 2005, Venezuelan production by hectare was one of the highest in Latin America. Part of the industry success was built upon domestication of the species and selection of favorable traits and to work under closed cycle conditions, which have led to the possibility to stay free -for more than two decades- of severe viral diseases such as Taura and White Spot virus. However, by 2005 Taura virus was confirmed affecting a total of 67% farms in Zulia, Falcón and Nueva Esparta States. Epidemic diseases have lead to farmers to look for new alternatives, one of which is the culture of marine shrimp in inland low-salinity water. The aim of this present study was to culture L. vannamei marine shrimp in inland low-salinity water in Paraguana, Falcon State, Venezuela. Postlarvae at PL12 stage, were cultured in a 969 m2 pond. Before culturing, samples of water and soils were analyzed to accomplish recommended culture parameters for L. vannamei in low-salinity conditions. Postlarvae studied came from a genetic program and were acclimated by reducing salinity to 4 ppm through 58.5 hours. Once acclimation was reached, postlarvae were stocked at a density of 42 PLs/m2. Physical and chemical parameters were registered during culture (dissolved oxygen, salinity and temperature). A pellet dry-diet K-maron 35® was given as diet. Survival percentage, average weight, growth rate (g/week), total average length, feed conversion rate and productivity were evaluated through monthly sampling. Data were analyzed through descriptive statistics. L. vannamei marine shrimp was cultured during 94 days and the following production data was registered: 65.19% survival, 10.66 gr. average weight, feed conversion factor of 1.01:1 and a productivity level of 2,579.98 kg/ha/cycle. Results show this type of culture is highly feasible and it might become a new alternative for the small-medium local agriculture producers of Paraguaná-Falcón, Venezuela.
ABSTRACT
Microbiological studies in a modified extensive shrimp culture system at Nambuthalai, southeast coast of India were carried out for a period of 120 days. Population dynamics and distribution profile of luminous bacteria and total heterotrophic bacteria in the water, sediment and animal samples were monitored. Luminous bacteria associated with exoskeleton, gills and gut were isolated and quantified. The total heterotrophic bacterial counts ranged from 1.3 x 104 to 25.3 x 104 CFU ml-1 in water and 1.5 x 106 to 26.2 x 106 CFU g-1 in sediment. The V. harveyi population density varied between 0.6 x 104 and 8.8 x 104 LCFU ml-1 in water and from 1.2 x 106 to10.4 x 106 LCFU g-1 sediment respectively. The gut of the animal was found to harbor high density of V. harveyi than gills and exoskeleton. The total heterotrophic bacteria and V. harveyi population density showed increasing trend during the culture period. The high V. harveyi density observed in this study at the end of the culture period correlated with the outbreak of white spot disease.
ABSTRACT
This study was elaborated to identify and describe the main links of the sea shrimp productive chain in the municipal district of Laguna, historically known as the main sea shrimp (Litopenaeus vannamei) production area in the State of Santa Catarina, Brazil. The study, held from April to July 2005, previously identified the local productive process through observation, interviews and bibliographical research. Afterwards, specific questionnaires were elaborated for each of the several segments connected to the local activity. A total of 90 interviews were conducted, intending to map out the procedures and functionality of the productive chain, from the necessary inputs for production to the moment of shrimp acquisition by final consumers. Results indicated that the entire productive chain requires actions that range from improvement of sanitary and genetic conditions of larvae to product commercialization. Reduction of bureaucracy in public organs, better investment credit conditions, improvement in productive practices, training of technical and productive labor, and reduction of production costs will not occur until industrialization politics and commercialization of local production are standardized.
O presente estudo foi elaborado para identificar e descrever os principais elos da cadeia produtiva no município de Laguna, região que historicamente constitui-se em principal área de produção de camarão marinho (Litopenaeus vannamei) em Santa Catarina, Brasil. O estudo foi desenvolvido de abril a julho de 2005, a partir de uma prévia identificação do processo produtivo local, através de observação, entrevistas e busca bibliográfica. Foram elaborados questionários específicos para os vários segmentos atrelados à atividade local. Foi realizado um total de 90 entrevistas, pretendendo-se fazer um acompanhamento do desempenho e funcionalidade da cadeia produtiva desde os insumos necessários à produção até o momento da aquisição do camarão pelo consumidor final. Os resultados indicam que todos os elos descritos necessitam ações que visem desde o melhoramento sanitário e genético das pós-larvas até a comercialização do produto. Desburocratização dos órgãos públicos, maior acesso ao crédito para investimentos, melhorias nas práticas produtivas, capacitação da mão-de-obra técnica e produtiva e redução de custos produtivos não ocorrerão até haver uma normalização das políticas industriais e de comercialização da produção local.
Subject(s)
Animals , Humans , Aquaculture/methods , Penaeidae , Aquaculture/organization & administration , Brazil , Consumer Behavior , Interviews as TopicABSTRACT
Osmoregulation in Litopenaeus vannamei was studied in a factorial experiment at four temperatures (20, 24, 28 and 32 degrees C) and six salinities (10, 16, 22, 28, 34 and 40 per thousand). The isosmotic related points for 20, 24, 28, and 32 degrees C were 754, 711, 822, and 763 mmol/kg, respectively. This species hyperregulates between at salinities of 10 and 20 per thousand and hyporegulates between 20 and 40 per thousand. The isosmotic point in L. vannamei exposed to constant salinities changed in relation to temperature from 717 to 823 mmol/kg. For these experimental conditions, the T-S combination of 32 degrees C and 28 per thousand produced the best growth.
La respuesta osmorreguladora de Litopenaeus vannamei se estudió en un experimento factorial con cuatro temperaturas (20, 24, 28 y 32 ºC) y seis salinidades (10, 16, 22, 28, 34 y 40 ). Los puntos isosmóticos relacionados para 20, 24, 28, y 32 ºC fueron 754, 711, 822, y 763 mmol/kg, respectivamente. Esta especie hiperregula dentro del intervalo de 10 y 20 e hiporegula entre 20 y 40 . El punto isosmótico de L. vannamei expuesto a salinidades constantes cambia en relación a la temperatura desde 717 a 823 mmol/kg. Para estas condiciones experimentales, la combinación T-S de 32 ºC y 28 produjo el mejor crecimiento.