Intensification of white shrimp Litopenaeus vannamei (Boone) larviculture

The objective of the present work is to contribute to the development of new culture techniques for the intensification of Litopenaeus vannamei larviculture through the use of recirculating aquaculture systems (RAS). Ammonia tolerance of L. vannamei larvae at different developmental stages and sub-stages was determined. A first attempt of intensification of larval rearing techniques was made through the implementation of an experimental RAS. The experiments evaluated the effects of high stocking density, feeding strategy and recirculation rate on the survival and growth of L. vannamei larvae. Based on these results, pilot-scale experiments with a compact RAS of 1 m3, applying a stocking density of 1000 larvae L-1 and a water exchange rate of 500% day-1, were conducted. A lower survival was recorded for the intensive larval RAS compared to a traditional aquaculture system (TAS). When including umbrella-stage Artemia as new prey in the feeding regime of the RAS, dry weight and biomass increased. The survival and growth in the RAS were similar to those obtained in TAS. In conclusion, the findings of this thesis demonstrate that the intensification of L. vannamei larviculture is feasible through the implementation of RAS. RAS proved effective in producing high quantities of good quality larvae, maximizing biomass, controlling water quality, reducing operating costs, and increasing biosecurity

Aquaculture Asia, Vol.14, No.4, pp.1-52, October - December 2009

Sustainable aquaculture Peter Edwards writes on rural aquaculture Edwards, P. Mussel farming initiatives in North Kerala, India: A case of successful adoption of technology leading to rural livelihood transformation Laxmilatha, P., Thomas, S., Asokan, P.K., Surendranathan, V.G., Sivadasan, M.P., and Ramachandran, N.P. Selective study on the availability in indigenous fish species having ornamental value in some districts of West Bengal Panigrahi, A.K., Dutta, S. and Ghosh, I. Aquaculture livelihoods service centres in Aceh, Indonesia: A novel approach to improving the livelihoods of small scale fish farmers Ravikumar, B. and Yamamoto, K. Research and farming techniques e-Sagu Aqua - an innovative information and communication technology model for transfer of technology for aquaculture Vimala, D. D., Ravisankar, T., Mahalakshmi, P., and Kumaran, M. Freshwater pearl crop: an emerging enterprise in the Indian subcontinent Misra, G., Jena, J. and Kumar, K. Genetics and biodiversity Preliminary risk assessment of Pacific white leg shrimp (P. vannamei) introduced to Thailand for aquaculture Senanan, W., Panutrakul, S., Barnette, P., Chavanich, S., Mantachitr, V., Tangkrock-Olan, N., and Viyakarn, V. Farmer profile Aquatic animal health Asian fish health experts visit Australia Olsen, L. and Ingram, B. (Fisheries Victoria) Black gill disease of cage-cultured ornate rock lobster Panulirus ornatus in central Vietnam caused by Fusarium species Nha, V.V., Hoa, D.T. and Khoa, L.V. Marine Finfish Aquaculture Network Effects of the partial substitution fish oil by soybean oil in the diets on muscle fatty acid composition of juvenile cobia (Rachycentron canadum) Hung, P.D. and Mao, N.D. Growth response of cobia Rachycentron canadum (Pisces: Rachycentridae) under the hypersaline conditions of the Emirate of Abu Dhabi Yousif, O.M.*, Kumar, K.K. and Abdul-Rahman, A.F.A. NACA Newslette

Evaluation of nematodes and artificial artemia as feed for pacific white shrimp in a biofloc nursery system

The global aquaculture production is growing immensely in all aspects and has already surpassed the output from wild caught fish and shellfish industries. The farming of Penaeus vannamei is one of the biggest contributors to this market. But many early stages of aquaculture depend on the finite and volatile resource Artemia as a live feed. This dependency has been identified as a bottleneck for future growth and sustainability progress. In this experiment, one artificial Artemia product and one nematode species were tested and evaluated in a feeding trial as potential replacements for live Artemia in a zero-water exchange biofloc nursery system. P. vannamei post larvae (PL) were stocked at a density of 60 PL/L in 60-L tanks. They were reared from PL12 – PL33 and fed 8 times per day with a dry feed (DF). Different treatments with four replicates each received a diet supplement of either live nematodes (N), live Artemia (LA), artificial Artemia (AA), or DF (control, C). The PL that received the live diets had nearly twice the survival rate compared to the ones only fed inert diets (N: 94 ± 6%, LA: 91 ± 7%, AA: 53 ± 11%, C: 51 ± 10%). Growth parameters were slightly better in the two inert diet groups (wet weight: N: 22.5 ± 5 mg, LA: 22.5 ± 5 mg, AA: 35 ± 5.7, C: 35 ± 10; Total length: N: 15.8 ± 3.9 mm, LA: 15.8 ± 3.2, AA: 17.1 ± 5.1 mm, C: 17.3 ± 5.0). No significant differences were detected in survival to salinity stress. In addition, beneficial effects on the biofloc and on the water quality were observed in the live diet groups and their causation should be further investigated. The results show that the nematode species Panagrolaimus sp. (NFS 24-5) can completely replace live Artemia in a co-feeding regime.Nas últimas décadas a produção aquícola global experimentou um imenso crescimento em quantidade, variedade de espécies cultivadas e sistemas de produção. Desde 2014 que a aquicultura ultrapassa a produção mundial de peixes e mariscos capturados. O crescimento sem precedentes da população humana é o principal motor de uma procura crescente de proteína aquática de alta qualidade. O cultivo do crustáceo marinho Penaeus vannamei é um dos maiores contribuintes para este mercado. No entanto as fases iniciais das produções de muitos moluscos e peixes dependem de Artemia como alimento vivo, um recurso finito e volátil. Os cistos de Artemia só podem ser colhidos em algumas regiões do planeta e sua produção está sujeita a grandes flutuações naturais, o que limita sua exploração contínua. A dependência de Artemia por parte da indústria da aquicultura foi identificada como um estrangulamento ao crescimento e progresso do sector. A grande procura de proteína aquática levou a uma enorme pressão sobre muitos recursos naturais, em todos os tipos de ecossistemas aquáticos, desde os oceanos às águas interiores e passando pelos ambientes costeiros. A resposta da aquicultura tem de ser persuasiva no sentido de dar garantias de sustentabilidade, mantendo as suas atividades dentro de limites saudáveis. A obtenção de autonomia relativamente à Artemia poderá simplificar significativamente os processos de alimentação durante as fases larvares e, eventualmente, promover a sustentabilidade da aquicultura em geral. Os produtos artificiais de Artemia já estão comercialmente disponíveis mas sua capacidade de alimentar eficientemente larvas de camarão ainda carece de testes científicos. Mais recentemente, uma espécie de nematode foi identificada como tendo propriedades semelhantes às dos cistos de Artemia: armazenamento a longo prazo em estado desidratado, processo de reidratação simples, tamanho pequeno para fácil ingestão e valor nutricional adequado para larvas de camarão. Além disso, estão disponíveis métodos de produção em massa, sustentáveis e economicamente viáveis, que facilitam sua aplicação comercial. Nesta experiência, um produto artificial de Artemia e uma espécie de nematode foram testados e avaliados num ensaio de alimentação como substitutos potenciais de Artemia viva num sistema de viveiro biofloco sem troca de água. Os sistemas Biofloc dependem do controle de nitrogénio através de processos microbianos que ocorrem dentro do tanque de cultivo, o que reduz substancialmente a renovação de água com o benefício adicional de fornecer proteína bacteriana. As pós-larvas (PL) de P. vannamei foram estabuladas com uma densidade de 60 PL por L em tanques semi-cónicos de 60 L. As larvas foram criadas a partir de PL12 - PL30 e alimentadas 8 vezes por dia com ração seca. Diferentes tratamentos com quatro replicados receberam um suplemento alimentar de nemátodos vivos (N), Artemia viva (LA), Artemia artificial (AA) ou ração seca (controle, C). As PL que receberam as dietas vivas tiveram quase o dobro da taxa de sobrevivência quando comparadas às alimentadas apenas com dietas inertes (N: 94 ± 6%, LA: 91 ± 7%, AA: 53 ± 11%, C: 51 ± 10%). No entanto, os parâmetros de crescimento foram ligeiramente melhores nos dois grupos de dieta inerte (peso húmido: N: 22,5 ± 5 mg, LA: 22,5 ± 5 mg, AA: 35 ± 5,7, C: 35 ± 10; Comprimento total: N: 15,8 ± 3,9 mm, LA: 15,8 ± 3,2, AA: 17,1 ± 5,1 mm, C: 17,3 ± 5,0). O efeito do stress salino não foi significativo. Nos grupos de dieta viva foram observados efeitos benéficos na formulação de bioflocos com reduzida acumulação de sólidos suspensos, totais e voláteis. A dieta de nematode também teve níveis de nitrito significativamente menores, indicando melhor controlo do nitrogénio e parâmetros gerais de qualidade da água. O contexto e a causalidade dessas diferenças devem ser investigados, pois podem ser relevantes para operações de aquicultura usando sistemas de bioflocos. Em conclusão, a experiência verificou que a espécie nematode Panagrolaimus sp. (NFS 24-5) pode substituir completamente Artemia viva num regime de co-alimentação. Os resultados deste estudo de alimentação podem promover a sustentabilidade da criação de camarão por meio de alimentos alternativos, independentes dos recursos finitos de Artemia

Microbiome in shrimp Litopenaeus vannamei aquaculture : dynamic changes and bacterial lifestyles

The Pacific white leg shrimp Litopenaeus vannamei is the most frequently cultured shrimp species, comprising more than 70% of the world shrimp commodities since 2010. Shrimp indoor and outdoor aquacultures are affected by water quality deteriorations and bacterial diseases. These cultivation problems lead to a substantial annual loss of shrimp harvest. Traditionally, water quality is quantified by plankton density, total suspended solids/particulate matter, pH, salinity and inorganic nutrients, particularly ammonium, nitrite and phosphate. Especially, the quantitative assessment of the carbon cycle in shrimp aquaculture is required to determine oxygen demand and depletion. However, optimal and acceptable but potentially stressful conditions have not systematically been determined in pond aquaculture. Excess biomass formed by photosynthesis of phytoplankton and by heterotrophic bacteria in the microbial loop poses a particular problem in shrimp aquaculture. While particulate matter in pond water may serve as additional feed source for shrimps, it also provides niches for particle-associated bacteria, such as pathogenic Vibrio species. In this study, water quality parameters as well as bacterial community compositions were observed in Indonesian shrimp aquacultures over the complete rearing process. Semi-intensive and intensive aquacultures differed in suspended particulate matter content, chlorophyll a, pH, and dissolved oxygen, while inorganic nutrient concentrations and the population size of cultivable heterotrophic bacteria were comparable. Halomonas, Salegentibacter, and Sulfitobacter were the most abundant free-living bacteria, whereas particle-associated bacteria were dominated by Halomonas and Psychrobacter. Vibrio were more frequently found in the intensive aquaculture system, particularly in the particle-associated fraction and at low pH conditions. White feces disease (WFD) event, which is a disease repeatedly occurring in shrimp aquaculture, was further documented in this thesis. To better understand pond water conditions as well as bacterial community dynamics during the disease event, the quantification of physico-chemical water parameters was combined with molecular analyses of the microbiome of shrimps, feces, and aquaculture water including the particles. The WFD event coincided with a low water pH and a high proportion of Alteromonas in the feces. Virulence genes of Vibrio, i.e toxin regulator (toxR) and termolabile hemolysin (tlh) were detected in the particle fraction ( 3 AAmicrometre), in the intestine of healthy shrimps and feces of WFD-infected shrimps. An increase of pH above 8 via limestone addition enabled a recovery from WFD. In addition, the bacterial community composition also changed with the rise in pH. This observation led to a recommendation, that aquacultures of L. vannamei should maintain a pH above 8. Lastly, bacterial dynamic on aggregates, which form in large numbers in shrimp aquaculture, was investigated to monitor the growth of potential pathogenic Vibrio species. In the rolling tank experiments, the addition of carbon-rich molasses was shown to rapidly reduce toxic ammonium and nitrite pools. Furthermore, it enabled the fast growth of halophilic heterotrophic bacteria, such as Halomonas, Psychrobacter, and Salegentibacter. Conversely, in the presence of Chlorella vulgaris aggregates V. parahaemolyticus population remained constant without decay. The algal biomass seemed to maintain the Vibrio population and density. I conclude that water parameters such as salinity and pH shape bacterial communities in shrimp pond aquaculture, and that a deterioration of water quality may cause detrimental shifts in bacterial community composition. However, bacterial communities will recover to the initial composition if water parameters are adjusted to former condition. To improve shrimp farming practices, I propose to perform regular pond water assessment, not only for the physicochemical parameters, but also for bacterial community composition. For this purpose, I recommend to analyze the bacterial communities in the particle fraction, including virulence genes of pathogenic bacteria. In addition, sludge discharge and regular addition of lime stones are necessary to improve and maintain shrimp production. As consequence, sustainable shrimp pond farming systems should include sludge as well as clean water reservoirs

Feasibility of Using Biofuel By-Products as a Sustainable Nutritional Resource for Aquaculture Production of Litopenaeus vannamei

Many different algal species can provide an acceptable protein ingredient, with good digestibility, for shrimp feeds. Compared to fish meal, similar protein, carbohydrate, and lipid levels can be found in select algal species. Traditional shrimp diets in aquaculture rely on fish meal and fish oil from pelagic fish fisheries. A reduction or elimination of these ingredients would reduce the dependency of shrimp aquaculture on offshore fisheries and increase economic competiveness. Biofuel production produces algal by-products of potential use to aquaculturists that might reduce or eliminate the need for fisheries products in shrimp feed. Established uses for by-products from biofuel production include fertilizer for crops, fodder for swine and poultry, and production of methane and alcohol fuels. However, using biofuel production by-products as a protein and carbohydrate source for the Pacific white shrimp, Litopenaeus vannamei, has not been investigated. Therefore, a series of feeding experiments were conducted to evaluate if the algae used to produce biofuel could be a suitable main protein source in formulated diets for L. vannamei. The feasibility of substituting biofuel algae by-product for fish meal in the juvenile L. vannamei (0.0306 ± 0.0011 g) diet was evaluated, and an adequate substitution ratio was determined. Eighteen experimental diets were evaluated using 60, 80, and 100% fish meal substitution levels. Chaetoceros calcitrans, Nannochloropsis salina, and Pavlova sp. were chosen as the algae sources as they have potentially high use in biodiesel production due to their high lipid content and each has been included in established larval shrimp aquaculture operations. Each diet varied the level of fish meal substitution (60, 80, or 100%) and either contained dried algal biomass or, alternatively, dried algal biomass with reduced lipid content to simulate algal biomass post-biodiesel production. The diets were compared, relative to their effect on weight gain in juvenile L. vannamei, to each other and to a commercially available diet (CONTROL) and a diet formulated using the ingredients used in all of the experimental diet formulations but without algal biomass (BASAL). The shrimp were held individually in 355-ml Styrofoam cups filled with 200-ml seawater with a salinity of 32 parts per thousand (ppt) salinity under a 12:12 light:dark photoperiod. Water exchange was 90% per day for six days and 100% on the seventh day when weights were taken. Each of the twenty diets was presented daily to seven replicate cups, each cup containing a single shrimp, for six weeks. Food was presented once per day to satiation, which was determined by the shrimp refusing additional feed. Each animal was weighed weekly. After six weeks, the shrimp were harvested and final weights were taken. The analysis of differences between strains, levels, and lipids indicated there was a significant difference between all of the algal-based diets and the control. Overall, significantly better growth rates were observed in the diets with less fish protein replacement. The 60% fish meal replaced diets outperformed the diets that had 80 or 100% fish meal replacement. There were no significant differences in nutritional value among the algal species. Survival rates, from an aquaculture perspective, were acceptable for all treatments (\u3e71%). Results from these studies demonstrated that formulated diets using algal biomass from biodiesel production can be the primary protein source for L. vannamei postlarvae

Biofloc technology as an integral approach to enhance production and ecological performance of aquaculture

The general objective of this study was to explore the contribution of biofloc technology (BFT) application to aquaculture productivity enhancement, while maintaining sustainable practices. To increase biofloc utilization and overall nutrient utilization, the potential of biofloc utilization by some aquaculture species has been elucidated. This study shows that particle size plays an important role in the nutritional quality and in situ utilization of bioflocs by some aquaculture species. This information was used the basic knowledge to construct a BFT-based integrated culture with the aims to control suspended solids production and to increase nutrient utilization efficiency in an aquaculture system. It is demonstrated that combining BFT with an integrated culture system resulted in lower suspended solids, higher biomass production, total feed efficiency, as well as higher N and P recovery. Furthermore, it is shown in the present study that BFT application also brought about other beneficial effects for the cultured species i.e. enhancing the immunity and the reproductive performance. We demonstrated that the consumption of bioflocs by shrimp resulted in an increase of immune response leading to a higher resistance against infectious myo necrosis virus (IMNV) challenge. Similarly, higher resistance against Streptococcus agalactiae was also observed in tilapia larvae cultured in a biofloc system. Moreover, a notable beneficial effect of biofloc system on tilapia reproduction was also confirmed. It is important to note that the magnitude of the expected beneficial effects of biofloc system could be determined by the operational parameters applied in the aquaculture system. We confirmed that carbon source could affect the dissolved inorganic nitrogen profile in the cultured water, and that alkalinity should be closely monitored during the culture period. It is also observed that the addition of secondary species in a biofloc-based integrated system might influence the water quality dynamic in the culture system and did not necessarily reduce the dissolved nutrient waste. Finally, the present study demonstrated possible modifications to improve the ecological performance of a biofloc-based aquaculture system and new possible roles of this system in aquaculture production

A study of semi-intensive shrimp culture in Ecuador in relation to physical, chemical and biological conditions in the production ponds during El Nino and La Nina events (1996 to 1999)

Once every three, four or even seven years, the Southeast trade winds which blow west-ward across the tropical zone of the Pacific Ocean, from the shores of South America towards the Asian land mass, weaken and sometimes even reverse their direction. This phenomenon is known as El Nino. Conversely, the climatic condition known as La Nina is characterised by unusually cold ocean temperatures in the equatorial Pacific, as compared to El Nino. Global climate anomalies associated with La Nina tend to be opposite to those of El Nino. A study of shrimp culture in Ecuador was carried out to analyse the temporal changes in pond water quality, phytoplankton composition and diversity, and bacterial composition and diversity in the intestines of cultured Litopenaeus vannamei in Ecuador. These parameters were studied in relation to their impact on the growth, survival and production in a semi-intensive shrimp culture farm situated in the Chone River Estuary, Ecuador. Five culture periods were studied during the climatic events of El Nino, La Nina and transition periods (1996 to 1999 ). Shrimp were stocked in ponds at 10 PL/m2. Pond management included pond drying, inorganic fertilisation, and feeding with a commercial pellet twice a day. The physicochemical characteristics of the pond water and the phytoplankton and bacterial counts were estimated at intervals of 7-15 days of culture during each period of study. The concentrations of nitrite, nitrate, sulphide, ammonia, pH and suspended solids in the pond water in all ponds during the five culture periods fluctuated within ranges considered compatible with shrimp farming. Phosphorus, silica, temperature and salinity, however, showed significant differences during the five periods of shrimp culture, reaching sub-optimal levels during some culture periods. The species composition and diversity of phytoplankton was different during El Nino, La Nina events and transition periods, with a decrease in the diatom community and an increase in the cyanophytes algae community associated with changes in nutrients and nutrient ratios, and temperature, salinity is discussed. A low diversity of bacterial genera with a predominance of Vibrio spp., particularly V. harveyi and V. parahaemolyticus, was observed in shrimp intestines during disease outbreaks in the transition and La Nina periods associated with significant environmental changes in temperature and salinity. Shrimp performance was significantly different between El Nino, La Nina and transition climatic periods. Survival, feed conversion ratio and yield were better during El Nino periods because of the positive effects of higher pond water temperature and salinity (29°C and 28 psu) on the shrimp stocks