Influence of stocking density on water quality and growth performance in production of juvenile pirarucu, Arapaima gigas, in irrigation canals / Influência da densidade de estocagem na qualidade da água e na performance de crescimento na produção de juvenis de pirarucu, Arapaima gigas, em canais de irrigação

The pirarucu is reared in cages under intensive systems or ponds under semi-intensive systems. This research evaluates the effect of stocking density on water quality, survival and growth of juvenile pirarucu reared in net pens located in irrigation canals. Pirarucu (193.3±37.3 g; 31.5±2.1 cm) were stocked at densities of 3.6, 6 or 10 fish m-3 in 4.2 m3 net pens installed at the Irrigation District of the Coastal Tablelands (DITALPI), Parnaíba (Piauí, Brazil), with three replicate for each density. Fish were fed a formulated diet containing 40% crude protein and 14.2 MJ kg-1 of feed and cultured for 180 days. The physicochemical parameters of the water were at satisfactory levels for fish culture. Survival was 100.0% in all density tested. The final weight, weight gain and and absolute growth rate (AGR) were higher for the medium stocking density (6 fish m-3) than for fish at low stocking density (3.6 fish m-3) and high stocking density (10 fish m-3). Final weight gain, survival, and productivity have demonstrated that the production of pirarucu in net pens using water from irrigation canals can become a viable strategy and a cheaper alternative to increase fish production. In addition, it improves the efficient use of water by integrating two productive activities, agriculture and aquaculture

Marine shrimp farming in the state of Ceará: an analysis of the productive and economic parameters, in the period 2003-2012 / A carcinicultura marinha no estado do Ceará: uma análise dos parâmetros produtivos e econômicos, no período 2003-2012

Brazil was the third largest producer of white shrimp in Latin America, with 75,000 tons and R$600 million, in 2012. The present work focused on the impacts of the IMNV pathogen, the anti-dumping action imposed by USA and the exchange rate appreciation of Brazilian currency in marine shrimp culture in a semi-intensive system in Northeastern region and also on the identification of options for sustainable production. Data were collected on shrimp farms (Compescal and Aquafort) at Ceará state. During the period from 2003 to 2007, these factors affected directly the competitiveness of Brazilian farmed shrimp exportation. However, in 2007 the shrimp producers started to sell on domestic market, which made possible to increase their production, revenue, income and profit levels. In 2007, Compescal had a loss of R$ 2,582,000.00. Although in 2008 it had a profit of R$2,353,000.00, while in 2012 the profit has increased to R$ 11,940,000.00. Aquafort was able to successively increase its profit margin, from R$865,000.00, in 2007 to R$ 2,583,000.00 in 2012, representing an annual growth rate of 40%. The economic feasibility analysis showed that under simulated conditions, the IRR maintained a direct and more than proportional link to changes in shrimp feed and sales prices, as well to productivity

Effects of sodium chloride supplementation for Pacific white shrimp Penaeus vannamei diets, cultured in low salinity waters / Efeitos da suplementação do cloreto de sódio em rações para o camarão branco do Pacífico, Penaeus vannamei, cultivado em águas oligohalinas

The culture of Penaeus vannamei in low-salinity waters is a recent development in Brazilian Northeast. The purpose of this study was to investigate the effects of NaCl dietary supplementation on shrimp growth, survival, haemolymph osmolality and total hemocyte counts. In trial 1, earthen pond-reared shrimp ranging from 5 to 20 g were sampled at intervals for determination of haemolymph osmolality. Haemolymph osmolality was not influenced by the increased weight of shrimp. Juveniles shrimp (5-20 g) haemolymph osmolality were then evaluated 24 h after they had been transferred from pond water (0.5 ppt) to the seawater (35 ppt). Shrimp haemolymph osmolality increased with external salinity and ranged from 661.0 ± 25.2 mOsm/kg (D1) and 916.9 ± 40.1 mOsm/kg (D4). In trial 2, shrimp reared in low-salinity water (0.3-0.5 ppt) were distributed into five groups (control, D1, and treatments, D2, D3, D4 e D5) with four replicates. Diets consisted of the basal diet supplemented with 0 g/kg, 5 g/kg, 10 g/kg, 20 g/kg, and 40 g/kg of NaCl, respectively. After 22 days, differences in survival, final weight, specific growth rates (SGR) and absolute growth rate (AGR) among treatments were significant. However, there were no significant trends in haemolymph osmolality and shrimp total hemocyte counts within the five tested groups

Efeitos da suplementação do cloreto de sódio em rações para o camarão branco do Pacífico, Penaeus vannamei, cultivado em águas oligohalinas / Effects of sodium chloride supplementation in diets for the Pacific white shrimp, Penaeus vannamei, reared in low salinity waters

O cultivo de Penaeus vannamei em águas oligohalinas tem sido um desenvolvimento recente na região Nordeste. O objetivo deste estudo foi investigar os efeitos da suplementação de NaCl em dietas no crescimento, sobrevivência, osmolalidade da hemolinfa e contagem total de hemócitos dos camarões. No experimento 1, camarões cultivados em águas oligohalinas, com peso variando entre 5 a 20 g, foram utilizados para a determinação da osmolalidade da hemolinfa, não tendo diso influenciada pelo aumento do peso do camarão. Após aclimatação em água do mar (35 ppt), a osmolalidade da hemolinfa foi avaliada em camarões com peso entre 5-20 g, tendo sido incrementada para a salinidade da água do mar (35 ppt), variando de 661,0 ± 25,2 mOsm/kg (D1) a 916,9 ± 40,1 mOsm/kg (D4). No experimento 2, camarões cultivados em águas oligohalinas (0,3-0,5 ppt) foram distribuídos em cinco tratamentos (D1, D2, D3, D4 e D5), com quatro repetições. As dietas consistiram de uma dieta basal suplementada com 0 g/kg, 5 g/kg, 10 g/kg, 20 g/kg e 40 g/kg de NaCl, respectivamente. Após 22 dias, os parâmetros de sobrevivência, peso final, as taxas específicas de crescimento (SGR) e taxa de crescimento absoluto (TCA) apresentaram diferenças significativas entre os tratamentos. No entanto, não houve diferenças significativas na osmolalidade da hemolinfa e contagem total de hemócitos dos camarões distribuídos nos cinco grupos

Mapping, technical and environmental aspects of shrimp farms in the Acaraú River Estuary, Ceará State, Brazil / Mapeamento, aspectos técnicos e ambientais de fazendas de camarão no Estuário do Rio Acaraú, Ceará, Brasil

Despite the economic importance of shrimp farming, a number of technical problems have been widely reported in the literature. This article focuses on the environmental and socioeconomic impacts of semi-intensive/intensive shrimp farming in the Acaraú river estuary. This estuary has the second largest number of farms in the Ceará state. Currently, the industry has 31 participating farms with a total area devoted to shrimp farming of 1,571.58 ha. In 2013, total production was 7,853.92 tons of shrimp with an average yield of 5.88 t ha-1 year-1 in an earth pond area of 1,335.49 ha. This industry employs 1,382 people, representing 17.3% of the jobs generated in the two municipalities where the Acaraú river estuary is located. The main environmental impacts of this industry are water pollution and loss of mangroves. However, no changes in water quality parameters were observed during the period 2011-2013, indicating that this estuary has some nutrient processing capacity derived from nurseries, while 159.4 ha of mangrove forests were occupied by In the same period of the establishment of the farms, this estuary presented an increase of 987.41 ha of this landscape unit. The results of this research demonstrate that the Brazilian shrimp industry requires an improvement in management practices to achieve sustainable growth

Use of Lithothamnium sp. (Algen® Oceana) in Penaeus vannamei culture / Uso do Lithothamnium sp. (Algen® Oceana) no cultivo de Penaeus vannamei

The process of preparing the soil for ponds is a very important phase of production. The selection of the type of limestone used in the pH correction process will directly influence the quality of the soil, water, natural food production and the development of Penaeus vannamei. The objective of this study was to evaluate a substitute for one of the types of limestone used in pond liming, originated from the limestone algae Lithothamnium sp., commercially named Algen® (Oceana, Tutóia, Maranhão, Brazil), verifying its efficiency in relation to dolomitic limestone. The study was conducted at the shrimp farm Monólitos Aquacultura Ltda (Banabuiú, Ceará, Brazil). The monitoring and evaluation of the used products, soil physical-chemical properties, physical-chemical and biological analyses of the water, and the zootechnical performance of the shrimp were performed during two production cycles between November 2017 and July 2018 in three ponds with an area of 1.0 ha. The results showed that the use of Algen® showed similar action to the parameters obtained with the use of dolomitic limestone, both in terms of soil and water quality aspects and for the zootechnical performance of P. vannamei. However, a better zootechnical performance of P. vannamei was observed when Algen® was used in the 500 kg/ha concentration