ABSTRACT. The present study evaluated the effect of different energy levels (15.07, 15.91, 17.17, 18.00, and 19.68 kJ g−1 of diet) on isoproteic practical diets for Macrobrachium amazonicum during the nursery phase on the zootechnical performance and proximate composition of the whole body. Postlarvae with a mean weight of 0.043 ± 0.01 g were stored in 25 experimental units, at 150 animals per m2, in a completely randomized design with five treatments and five replicates. The post-larvae were evaluated at the end of the experimental period according to the pre-established performance parameters. The analysis of variance for regression (α = 0.05) allowed us to estimate that the maximum final weight was observed in the treatment with 16.74 kJ g−1. In contrast, the lowest apparent feed conversion was observed at the 16.43 kJ g−1 level. The best values were found in 17.29 and 17.50 kJ g−1, respectively, for the energy and protein retention rates. As the best fit of the equation was presented for the energy retention ratio (R2 = 0.63), which approached the treatment of 17.17 kJ g−1, this energy level is recommended in postlarvae diets.

ABSTRACT Four treatments were established to evaluate the effect of delayed first exogenous feeding and subsequent feeding periods on the development of goldfish larvae. The fasting and feeding periods were arranged as follows: T1 (0DFA:30DF), T2 (4DFA:26DF), T3 (8DFA:22DF), and T4 (12DFA:18DF), where DFA are the days of fasting and DF are the days of feeding. The larvae were kept in community tanks for each repetition, with 75 larvae per tank (3.75 larvae L−1). There was no significant difference in total length or final weight between larvae submitted to 0, 4, and 8 days of feed deprivation. However, larvae submitted to 12 DFA had higher values of the same variables than the other treatments. No significant difference in larval survival was observed between T1, T2, and T3, but T4 negatively influenced survival. Under the conditions evaluated, the point of no return was 4 DFA. Dead larvae were partly eaten in the fasting treatments. The delayed first feeding should be avoided in large-scale productions since it significantly reduces survival during cultivation. This article results from research funded by the Pescarte Environmental Education Project (PEA/IBAMA).

ABSTRACT The objective of this study was to identify morphological characteristics of different populations of Penaeus schmittiBurkenroad, 1936 to contribute to its biology and conservation. In order to compare geographically isolated populations, between 2014 and 2016, selected biological variables were analyzed in six populations dispersed along the Brazilian coast and one from the Cuban coast. Specimens with eight upper rostral teeth predominated. The ordination of shrimp measurements by non-metric multidimensional scaling showed the greatest dispersion on data from Cuba, Rio Grande do Norte, and Espirito Santo, which are also the localities that presented the highest coefficient of variation. On the other hand, the values corresponding to Sergipe, Rio de Janeiro, Paraná, and Santa Catarina showed a greater similarity or clustering of the data of each location. Tail weight was estimated using length and depth of the sixth abdominal segment. The populations of Santa Catarina, Brazil (28°S), had the longest and heavier abdomens proportionally among all the compared populations, while the organisms of Manzanillo, Cuba (20°N), had proportionally shorter abdomens and the narrowest cephalothorax. The regression equation indicated a positive allometric growth for P. schmitti, and the largest total length reported for genus Penaeus in the natural environment corresponded to a P. schmitti specimen. This information could be useful in future taxonomic studies to correctly identify the species and its morphological variability. Color differences were also observed, with white ventral spots in the sternite XIV of some females from Brazilian populations, which was not previously reported in the literature. Extending these studies is recommended to contribute to the conservation and culture of P. schmitti.

ABSTRACT Experiments were carried out to study the effects of ammonia and nitrite on food consumption of Macrobrachium amazonicum postlarvae. Postlarvae (average weight of 0.0625 g) were exposed during 21 days to four concentrations of total ammonia (0, 1.05, 2.1 and 4.2 mg. NH3+NH4+ L-1) and four concentrations of nitrite (0, 0.075, 0.15 and 0.30 mg N-NO2- L-1). After the exposure period, six prawns per treatment were maintained individually in 250 mL experimental units to analyze the food consumption as a function of the amount of food offered and the leftovers during a 24 h period. The food consumption presented significant alterations for prawns exposed to all nitrite concentrations and at concentrations of twice the recommended safety level for total ammonia. According to the results obtained, high concentrations of total ammonia and nitrite affect the food consumption of M. amazonicum adversely, influencing the species performance in culture systems.

ABSTRACT To compare the zootechnical performance of the Brazilian native shrimp Penaeus schmitti and the exotic shrimp Penaeus vannamei, juveniles were grown under controlled conditions. Both species were simultaneously cultivated (monoculture) in separate 70 L plastic tanks at two different densities: 30 and 50 ind m-2. Also, in the other two treatments, both species were cultivated together (mixed), with and without feeding, at 30 ind m-2. During the experiment, P. vannamei generally showed a greater interest in food and voracity than P. schmitti. At harvest, for both stocking densities of monoculture treatments, the mean growth rate observed for P. vannamei was 1.0 g week-1, while P. schmitti achieved only 0.1 g week-1. The mean final weight was 10.4 ± 2.0 g; 10.7 ± 2.1 g for P. vannamei and 2.8 ± 0.3 g; 3.2 ± 0.3 g for P. schmitti, for respective densities of 50 and 30 ind m-2. In the mixed treatment with feeding, while P. vannamei reached 11.9 ± 1.4 g, P. schmitti reached only 2.6 ± 0.4 g in the same tank. The observed differences were 3.7 and 3.4 higher in favor of P. vannamei in the monoculture treatment, and up 4.5 times higher in the mixed treatment. Under strict fasting conditions, both species practiced predation/cannibalism among themselves. The results reflected the zootechnical advantages of P. vannamei, but also corroborated the negative effect that high densities and lack of natural food can exert over native species. The potential for P. schmitti cultivation and the possible impact of the escape of P. vannamei into the natural environment is discussed.

Resumo: Objetivo Este trabalho tem como objetivo registrar a ocorrência da espécie não nativa Macrobrachiun rosenbergii na bacia hidrográfica do rio Piquiri, Estado do Paraná, Brasil, um importante sistema hidrográfico Sul-Americano. Métodos As amostras foram coletadas de outubro de 2015 a junho de 2016 e de setembro de 2017 a setembro de 2018, utilizando armadilhas e equipamento elétrico de pesca (gerador de corrente alternada portátil, 2,5 kW, 400 V, 2A) no rio Piquiri e dois afluentes. Resultados 16 espécimes de M. rosenbergii foram capturados, 11 fêmeas e 5 machos. Conclusões Nossos resultados indicaram a introdução da espécie M. rosenbergii na bacia do rio Piquiri pela atividade de aquicultura. A constante inserção de novos espécimes pela aquicultura pode manter populações com elevado número de indivíduos, ocasionando potenciais danos à biodiversidade nativa.

Abstract: Aim The objective of this work is to record the occurrence of non-native species Macrobrachiun rosenbergii in water bodies of the Piquiri River basin, State of Paraná, Brazil, an important South American hydrographic system. Methods Samples were obtained from October 2015 to June 2016 and from September 2017 to September 2018, using traps and electric fishing equipment (portable alternating current generator, 2.5 kW, 400 V, 2A) in the Piquiri River and two tributaries. Results 16 M. rosenbergii specimens were caught, 11 females and 5 males. Conclusions Our results indicated the introduction of the species M. rosenbergii into the Piquiri River basin by aquaculture activity. The constant insertion of new specimens by the productive sector may, in the short term, maintain populations with large number of individuals, causing potential damage to the native biodiversity.

ABSTRACT Macrobrachium amazonicum is the native freshwater prawn species with the greatest potential for captive production in Brazil. The stable isotope carbon and nitrogen technique (δ13C and δ15N) is efficient to determine the contribution of different food sources to a given organism. We used this technique to estimate the contribution of the food sources in the biomass gain of M. amazonicum. Fish fillets were used to determine the isotopic fractionation between juveniles of M. amazonicum and a standard food source. Juvenile M. amazonicum were submitted to four treatments with different food availability to determine their contributions; T1: without soil substrate and with feed supply; T2: without soil substrate and feed supply; T3: with soil substrate, feed supply and addition of an aquatic macrophyte (Elodea sp.); and, T4: with soil substrate, aquatic macrophytes and without feed supply. Periphyton, plankton and precipitated organic material were present in all treatments. The isotopic fractionation was 0.57 ± 0.07 (carbon) and 2.14 ± 0.18 (nitrogen). The prawn fed with ration presented growth 2.4 and 2.82 times higher in the treatments without substrate (T1) and with substrate and macrophytes (T3), respectively. The contribution of the food sources reinforces omnivore in prawn. The benthic organisms and feed supply were fundamental for the better growth performance of M. amazonicum. Estimating the effective contributions of food sources can help in developing diets more adequate for the species, increasing productivity, reducing costs and reducing the environmental impact of waste substances.

ABSTRACT Biofloc system is an alternative to conventional aquaculture systems as it minimizes effluents, improves water quality, ensures greater biosafety due to minimal water exchanges and also serves as an additional food source for prawn. The present study aimed to evaluate the effect of suppression of vitamin and mineral supplements on diets for Macrobrachium rosenbergii reared in the biofloc system. Four experimental diets were evaluated: complete diet (Diet 1 with vitamin and mineral supplementation); diet without vitamin supplement (Diet 2); diet without mineral supplement (Diet 3) and diet without vitamin and mineral supplement (Diet 4). The experimental design was completely randomized with four replicates per treatment. After 45 days of trial survival rates above 90% and feed conversion rate ~1.83 were observed for all treatments, indicating that the production of M. rosenbergii in the biofloc system does not require the inclusion of vitamin and mineral supplementation in the feed.

ABSTRACT The objective of this study was to evaluate the effect of stocking densities on productive performance of the freshwater prawn Macrobrachium rosenbergii in biofloc system. Experimental tanks (microcosms) with 0.20 m2 area were used as experimental units. The tanks were connected to two 300 L matrix tanks (macrocosm) with biofloc technology, used as recirculating units. M. rosenbergii juveniles, with an initial weight of 0.315 ± 0.06 g and initial length of 33.34 ± 2.26 mm, was randomly distributed in the experimental tanks at different stocking densities (50, 100, 150, 200 and 250 ind m-2) and reared during 60 days. The total biomass at the end of the experiment was significant higher (P < 0.05) with the use of higher stocking density (250 ind m-2). However, prawns stocked at the density of 50 m-2 showed significant higher (P < 0.05) survival (73%) and significantly lower values (P < 0.05) for feed conversion rate (1.28). The different stocking densities evaluated did not affect the weight and length of prawns. The recommended density for growing M. rosenbergii in the biofloc system is 50 ind m-2.

There has been a considerable amount of work on the effects of Artemia enrichment on shrimp larvae. However, the effects on the subsequent growth performance have not been thoroughly investigated. From mysis I to eight day-old postlarvae (PL8), shrimp (Farfantepenaeus paulensis) were fed either newly hatched Artemia nauplii or Artemia enriched with an emulsion containing high levels of n-3 highly unsaturated fatty acids (n-3 HUFA). Upon reaching PL8, shrimp were exposed to salinity and ammonia stress tests. Growth performance was assessed by further rearing shrimp for 40 days. Shrimp fed the enriched Artemia (named EG) had higher tolerance to both salinity and ammonia than those fed newly hatched Artemia (named CG). Weight of PL from EG was also significantly higher than in CG. Higher levels of n-3 HUFA, especially 20:5 n-3 and 22:6 n-3, were found in the enriched Artemia. In the postlarvae, higher levels of n-6 and n-3 HUFA were observed in EG, while PL from CG presented higher levels of 18:3 n-3 and 18:4 n-3. At the end of the nursery rearing, no differences in survival were observed, but weight was higher in EG (1.08 g) than in CG (0.90 g). The supplementation of n-3 HUFA during larviculture increases the tolerance of F. paulensis postlarvae to salinity and ammonia, and positively affects growth performance after a 40 days long rearing period.

This work compared the use of dextrose and molasses as carbon sources for biofloc development, water quality maintenance, microorganism composition and growth performance of Litopenaeus vannamei juveniles in biofloc technology (BFT). Two treatments, dextrose and molasses, were tested with four replicates each. Carbon was added to achieve a C:N-AT (N-(NH3+NH4+)) ratio of 6:1. Physical and chemical water quality variables were monitored daily, and shrimp growth was estimated through periodic biometry. After 30 days, survival, final biomass, and feeding conversion rate (FCR) were determined. Dissolved organic carbon, chlorophyll-a, floc volume, total ammonia, nitrite, nitrate and phosphate concentrations, and microorganisms (qualified by groups), were measured every three days. Water quality variables remained within acceptable levels throughout the experimental period, except for nitrite, which reached higher levels than recommended for this species. The use of dextrose resulted in higher water transparency, which influenced the remaining centric diatoms. A superior shrimp performance was observed at this treatment, presumably because of variations on the microbial community. Therefore, it is concluded that the addition of dextrose results in a superior growth performance of L. vannamei when cultured in BFT systems.

Se comparó el uso de dextrosa y melaza como fuentes de carbono en el desarrollo del biofloco, mantención de la calidad del agua, composición microbiana y crecimiento de juveniles de camarón blanco Litopenaeus vannamei en sistemas de cría con tecnología de biofloco (BFT). Se probaron dos tratamientos, dextrosa y melaza, con cuatro réplicas cada uno. Se agregó carbono para mantener la relación carbono: N-AT (N-(NH3+NH4+)) en 6:1. Las variables físicas y químicas de calidad del agua se controlaron diariamente y el crecimiento de los camarones se estimó mediante biometría en forma periódica. Después de 30 días se determinó la sobrevivencia, biomasa final y tasa de conversión de alimento. Cada tres días se determinaron las concentraciones de carbono orgánico disuelto, clorofila-a, amonio total, nitrito, nitrato y fosfato, y microorganismos (de los grupos clasificados), en el agua. Las variables de calidad de agua se mantuvieran dentro de niveles aceptables durante el periodo experimental, excepto la concentración de nitrito que alcanzó niveles superiores a los recomendados para esta especie. El uso de dextrosa mostró una mayor transparencia del agua, lo que influyó en la mayor permanencia de diatomeas céntricas. En este mismo tratamiento los camarones tuvieron un mejor crecimiento debido probablemente a variaciones en la comunidad microbiana. Por esta razón, se concluye que la adición de dextrosa proporciona un mejor crecimiento del camarón blanco L. vannamei cultivado en sistema de bioflocos.

O objetivo deste estudo foi avaliar o efeito de altas densidades de estocagem na sobrevivência, crescimento e na taxa de conversão alimentar de camarões Litopenaeus vannamei, na fase final de engorda em sistema de Biofloc Technology (BFT), mantendo os mesmos parâmetros de água para todos os tratamentos. Os camarões (11,96 ± 1,14g) foram estocados em microcosmos (tanques de 0,50 m²), conectados a um raceway de cultivo BFT. O experimento teve duração de 45 dias. Os camarões foram estocados nas densidades de 150, 300, 450 e 600 camarões/m². Bioflocos foram coletados para análise de composição proximal. Os resultados foram submetidos à ANOVA uma via e as diferenças foram comparadas pelo teste de Tukey (α = 0.05). No T300 e T450, o crescimento e sobrevivência dos camarões não foram afetados pelas altas densidades. A maior biomassa alcançada (T450) foi de 5,1 kg/m² e a melhor conversão alimentar foi de 1,54 no T150. Os resultados deste estudo indicam que as densidades de estocagem no sistema proposto podem ser elevadas, mas não superiores a 450 camarões/m². Observou-se ainda que mesmo se a qualidade de água for mantida igual para todos os tratamentos, há efeito negativo entre densidade e crescimento dos camarões, confirmando que esse efeito é comportamental.

The aim of this study was to evaluate the effect of high stocking densities on survival, growth and feed conversion rates of Litopenaeus vannamei shrimp, in final growout phase, in a Biofloc Technology (BFT) culture system, keeping the same water parameters for all treatments. Shrimps (11.96 ± 1.14 g) were stocked in microcosms (0.50/m² tanks), connected to a BFT system raceway. The study was carried out for 45 days. The shrimp were stocked at densities of 150, 300, 450 and 600 shrimp/m². Bioflocs were collected for analysis of proximate composition. The results were submitted to one-way ANOVA, and differences were compared by Tukey test (α = 0.05). In T300 and T450, growth and survival were not affected by high stocking densities. The highest biomass reached (T450) was 5.1kg/m² and the best feed conversion rate was 1.54 in T150. The results of this study indicate that stocking densities in the proposed system can be high, but not exceeding 450 shrimp/m². Furthermore, even maintaining the same water parameters for all treatments, there was a negative effect between density and shrimp growth, confirming that this effect is behavioral.

O objetivo deste trabalho foi avaliar o uso de probióticos na produção de pós-larvas do camarão-rosa (Farfantepenaeus brasiliensis). Utilizou-se o delineamento experimental inteiramente casualizado, com dois tratamentos - uso de probióticos (Bacillus spp.) e controle com uso de antibiótico (eritromicina) - e quatro repetições. Pós-larvas no estágio PL1 foram estocadas em cada parcela experimental (3,0 L) e cultivadas até o estágio PL10. As variáveis de qualidade de água e o desenvolvimento de bactérias do gênero Vibrio, na água de cultivo, foram monitorados ao longo do experimento. Ao final do período experimental, as pós-larvas foram avaliadas qualitativamente e quanto à sobrevivência, ao peso e ao comprimento. Nas variáveis de qualidade de água, apenas o nitrito apresentou valor significativamente maior no tratamento com antibiótico. Para as variáveis peso e comprimento final, não houve diferenças significativas entre os tratamentos. Não foram observadas diferenças significativas entre os tratamentos quanto à qualidade das pós-larvas e à concentração de Vibrio spp. na água. A utilização de antibiótico pode ser substituída pelo emprego de probióticos durante a produção de pós-larvas de F. brasiliensis.

The objective of this work was to evaluate the use of probiotics in the production of postlarvae of pink shrimp (Farfantepenaeus brasiliensis). A completely randomized experimental design was used, with two treatments - use of probiotics (Bacillus spp.), and a control using antibiotic (erythromycin) -, and four replicates. Postlarvae in the PL1 stage were stocked in each experimental unit (3.0 L) and cultured until stage PL10. Water quality variables and the development of the bacteria of the genus Vibrio, in the culture water, were monitored throughout the experiment. At the end of the experimental period, postlarvae were evaluated qualitatively and for survival, weight, and length. Regarding water quality variables, only nitrite was significantly higher in the antibiotic treatment. For the variables weight and length, there were no significant differences between treatments. No significant differences between treatments were observed in postlarvae quality and in the concentration of Vibrio spp. in the water. The use of antibiotics may be replaced by probiotics during production of F. brasiliensis postlarvae.

A análise da criação de Farfantepenaeus brasiliensis e Farfantepenaeus paulensis em gaiolas, na Lagoa dos Patos, Rio Grande do Sul (RS), foi realizada a partir de juvenis produzidos em cativeiro com peso médio inicial de aproximadamente 1,2g. O experimento foi realizado em seis gaiolas (três gaiolas/tratamento), com abertura de malha de 5mm, área de fundo de 4m² durante 65 dias. A distribuição dos indivíduos nos tratamentos (F. brasiliensis e F. paulensis) foi aleatória, mantendo-se a densidade de 20 camarões m-2 nas unidades experimentais. A cada 15 dias foram realizadas biometrias para ajuste da quantidade de ração fornecida e avaliação do crescimento dos camarões. Ao final do experimento, foi realizada a biometria total dos camarões para avaliação da sobrevivência. Não houve diferença significativa entre a sobrevivência de F. brasiliensis (94,17 ± 9,04) e F. paulensis (98,50±0,71). O peso médio final foi significativamente maior para o F. brasiliensis (7,98± 0,94g); porém, não foram observadas diferenças significativas na produção de biomassa (127,81±17,93 e 126,65±1,74g m-2) e conversão alimentar aparente (1,39±0,27 e 1,57±0,09) de F. brasiliensis e F. paulensis, respectivamente. Os resultados indicam que F. brasiliensis apresenta potencial para produção em estruturas alternativas e incentivam que novas pesquisas sejam realizadas para o desenvolvimento de um pacote tecnológico de produção dessas espécies.

The cage culture of Farfantepenaeus brasiliensis and Farfantepenaeus paulensis was analyzed in the Patos Lagoon estuary using juveniles produced in captivity. Mean initial weight of the juveniles was approximately 1.2g. The experiment was conducted in 6 cages (3 per treatment), with mesh size of 5mm and bottom area of 4m², during 65 days. The individuals were randomly distributed into two treatments (F. brasiliensis e F. paulensis), keeping the stocking density of 20 shrimps m-2 in the experimental units (cages). Each 15 days shrimps were weighted to adjust the amount of feed and to evaluate growth. In the end of the experiment, all the shrimp were weighed and counted to determine the survival. Survival did not differ significantly between F. brasiliensis (94.17±9.04) and F. paulensis (98.50±0.71). Although the mean final weight was significantly higher for F. brasiliensis (7.98±0.94g), there were no significant differences in terms of total biomass production (127.81±17.93 e 126.65±1.74g m-2) and apparent feed conversion ratio (1.39±0.27 e 1.57±0.09) between F. brasiliensis and F. paulensis, respectively. The results indicate that F. brasiliensis show potential to be cultured in alternative systems and motivate the development of the technological package for culture of this species in the Patos Lagoon estuary.

Um pacote tecnológico para o cultivo do camarão-rosa em estruturas alternativas de baixo custo, gaiolas e cercados, vem sendo aplicado em conjunto com pescadores artesanais do estuário da Lagoa dos Patos, no extremo sul do Brasil. Embora a tecnologia para o cultivo intensivo de pós-larvas (PL) em laboratório já esteja bem documentada, informações referentes à sobrevivência e crescimento desses organismos na fase de berçário ainda são escassas para cercados e gaiolas no ambiente natural. Em virtude destes fatos, o objetivo do trabalho foi comparar o crescimento e a sobrevivência de pós-larvas de F. paulensis durante a fase de berçário em gaiolas e cercados no ambiente. Para o desenvolvimento do trabalho, foram utilizadas seis gaiolas (2,0 ´ 2,0 ´ 1,4 m) com malha de poliéster revestida de PVC com abertura de malha de 1,5 mm. Em cada unidade foram estocadas 800 PL26. Para verificar a influência do substrato, foram espalhados uniformemente 10 cm de sedimentos da própria enseada dentro de três gaiolas, simulando um cercado. A taxa de sobrevivência dos camarões obtida nas gaiolas foi de 92,2% e nos cercados de 88,7%, não sendo detectadas diferenças (P > 0,05). Porém, o peso médio final dos camarões nos cercados (1,05 ± 0,05 g), foi superior (P < 0,05) ao peso dos camarões nas gaiolas (0,88 ± 0,12 g). A espécie pode ser cultivada na fase de berçário em gaiolas ou cercados sem prejuízo à sobrevivência final. Entretanto, recomenda-se que a fase de berçário seja realizada preferencialmente em cercados.

Technology for the culture of the pink shrimp Farfantepenaeus paulensis in low-cost cages and pen enclosures was developed together with artisanal fishermen of the Patos Lagoon estuary, southern Brazil. Although the production of postlarvae (PL) under laboratory conditions is well documented, survival and growth during the nursery phase cages and pen enclosures in the nature has not yet been analyzed. Therefore, the present study compared survival and growth of F. paulensis postlarvae reared either in cages or pens. Six cages (2.0 ´ 2.0 ´ 1.4 m) of PVC-coated polyester with a mesh size of 1.5 mm were stocked with 800 PL26 each. To assess the effect of the substrate, a 10 cm layer of sand was added to three of these cages to simulate a pen enclosure. No difference in the mean survival rate between cages (92.2%) and pens (88.7%) was found (P > 0.05). However, final weight of shrimp reared in pens (1.05 ± 0.05 g) was higher than those kept in cages (0.88 ± 0.12 g). The nursery phase of F. paulensis in cages and pens did not affect survival. Nevertheless, because of the higher growth rate of shrimp grown in pen enclosures, this kind of structure should be preferentially used in nursery rearing of this species.