Helcio Luis de Almeida Marques

Integrated Freshwater Prawn Farming: State-of-the-Art and Future Potential

ABSTRACT Integrated aquaculture can be defined as aquaculture systems sharing resources with other activities, commonly agricultural, agroindustrial, and infrastructural. Freshwater prawns are excellent options for integration, since they are omnivores and can therefore take advantage of a wide range of feed residuals, either from aquatic or terrestrial species. Furthermore, due to their benthic habit, they have a well-defined spatial distribution in the environment, thus favoring interaction with various species of fish, other animals, and even with plants. The integrated farming of freshwater prawns includes different culture systems, such as polyculture and coculture with other aquatic species, rice-prawn culture, hydroponics, and integration with terrestrial animals and plants. Our review includes a worldwide perspective on the main commercial integrated systems involving freshwater prawns, the present status of research on integrated freshwater prawn production and the main opportunities for integrated freshwater prawn farming in a world that is moving toward sustainability. The review continues by providing a brief summary of the future prospects for this form of aquaculture. Finally, we conclude that integrating freshwater prawn farming with other aquaculture and farming activities has considerable potential as a means of increasing food production in a sustainable fashion.

Compensatory growth of Malaysian prawns reared at high densities during the nursery phase

Este trabalho foi realizado com o objetivo de verificar a ocorrencia de crescimento compensatorio em camaroes-da-malasia (Macrobrachium rosenbergii) cultivados em cercados, apos serem estocados em gaiolas sob altas densidades durante a fase de bercario. O experimento foi conduzido em gaiolas com 0,5 m2 e cercados com 2 m2 instalados em um viveiro de fundo natural com 2.400 m2. Pos-larvas (PL) de camaroes com peso medio de 0,026 ± 0,012 g (fase de bercario) foram inicialmente estocadas em 16 gaiolas, nas densidades de 50, 400, 800 e 1.200 camaroes m-2. Apos 60 dias, os camaroes foram transferidos para 16 cercados de engorda, na densidade de 12 camaroes m-2. O peso medio inicial dos camaroes nessa fase foi o peso medio final registrado na fase de bercario, como segue: 50 PL m-2 = 2,3 ± 0,3 g; 400 PL m-2 = 0,5 ± 0,03 g; 800 PL m-2 = 0,3 ± 0,05 g e 1.200 PL m-2 = 0,1 ± 0,01 g. Racao comercial para camaroes (35% de proteina) foi fornecida uma vez por dia, ao entardecer. Apos 244 dias, a sobrevivencia, o peso medio e a biomassa nao diferiram significativamente entre as densidades de cultivo. A taxa de crescimento relativo foi significativamente maior nos camaroes previamente estocados a 1.200 PL m-2 e a eficiencia da conversao alimentar, significativamente melhor para aqueles previamente estocados a 400 e 1.200 PL m-2. Esses resultados sugerem a existencia de crescimento compensatorio parcial em M. rosenbergii, o que pode viabilizar a estocagem de camaroes dessa especie em altas densidades na fase de bercario.

Prebiotic, probiotic, and synbiotic in the diet of Nile tilapia post-larvae during the sex reversal phase

This study evaluated the use of the prebiotic Active-MOS® (mannanoligosaccharides—Biorigin®) and two probiotics: PAS-TR® (Bacillus subtilis and Bacillus cereus var. toyoi—Imeve®) and Bioplus 2BC® (1.6xa0×xa01010xa0UFCxa0g−1 de Bacillus subtilis and 1.6xa0×xa01010xa0UFCxa0g−1Bacillus licheniformis—Christian Hansen®) tested separately and together, in the diet of Nile tilapia post-larvae during the sex reversal phase. The experiment was conducted in two stages: (i) a total of 2160 3-day-old post-larvae (PL) (10.39xa0±xa00.85xa0mm and 12.28xa0±xa03.15xa0mg) were used and distributed in 24 tanks of 40xa0L each (3.0xa0PLxa0L−1). Growth performance, chemical analysis of carcass, bacterial recovery, and histomorphometry of intestinal villi were evaluated; (ii) 240 tilapia (4.28xa0±xa00.19xa0cm and 1.19xa0±xa00.09xa0g) from the previous experiment were used and stocked at 10 PL per aquarium. The parameters evaluated were survival and relative protection level after bacterial challenge against Aeromonas hydrophila. Six treatments with four replications in a completely randomized design were used for both experimental stages. Additives in the diet of tilapia post-larvae did not determine significant differences in growth, survival, microbiological, or histomorphometric parameters in this study. Nevertheless, after the experimental infection, advantages on the use of the additives were observed in terms of higher relative protection levels (38.10%) and relative percent survival in fish receiving Active-MOS® + Bioplus 2BC®. Therefore, we recommend the use of synbiotic (Active-MOS® + Bioplus 2BC®) in the farming of Nile tilapia PL with recurrent outbreaks of bacterial diseases during the sex reversal phase.

Aspects of food management on amazon river prawn larviculture phase

The time supply of live food (Artemia nauplii) at the initial phases of development and the frequency of feeding with inert feed (egg custard) in Macrobrachium amazonicum larviculture were evaluated by two experiments: In Experiment I, newly hatched Artemia were offered to the larvae in three schedules (treatments): at 07:30 h (A07:30); at 12:00 h (A12:00) and 16:30 h (A16:30). In Experiment II, the inert food was offered in the following frequencies (treatments): twice a day at 08:00 and 17:00 h (IF2); three times a day at 08:00; 12:30 and 17:00 h (IF3) and four times a day at 08:00; 11:00, 14:00 and 17:00 h (IF4). Water quality variables (dissolved oxygen, pH, temperature, salinity, NH3 + NH4, NO2 and NO3) and production variables (weight, survival and duration of larviculture) were evaluated. The feeding managements studied did not influence significantly either the water quality and production variables. The results indicated that it can be recommended, for M. amazonicum larviculture feeding management, the supply of Artemia nauplii at early morning and inert feed two times per day (early morning and late afternoon), after stage V until the metamorphosis.

Influence of densities on the growth of brown mussel Perna perna L. cultivated in suspended socks at Caraguatatuba, southeastern Brazil

This study was carried out in a marine area at Cocanha Beach, Caraguatatuba, southeastern Brazil, aiming to determine the most appropriated density for brown mussel (Perna perna L.) cultured in suspended socks (French System), in order to reduce costs with acquisition of juvenile mussels (seed) and labor. In September 2007, 15 socks measuring 2xa0m each were reared at densities of 300, 400 and 500 seeds/m. After 250xa0days, mussels were harvested and separated in two length classes: non-commercial (<6xa0cm) and commercial (≥6xa0cm). Mussels were counted and weighed. In August 2008, the experiment was repeated with 1-m-long socks at lower densities (200, 250 and 300 seeds/m) in order to identify differences among commercial-sized mussels only. Data were analyzed by ANOVA or nonparametric Kruskal–Wallis test, followed by Tukey or SNK tests, respectively. The results suggest that it is feasible to use densities from 250 to 300 seeds/m, since biomass yields are similar to those registered at higher densities and the use of mussel seed is therefore optimized.