Resumo Um experimento foi realizado durante 95 dias para avaliar as densidades planctônicas do policultivo do camarão branco Litopenaeus vannamei e da tilápia do Nilo Oreochromis niloticus. O delineamento experimental foi inteiramente casualizado com seis tratamentos e quatro repetições cada. Os tratamentos foram: monocultivo com 10 camarões m2 (10S:0T); policultivo com 10 camarões e 0,5 tilápia m2 (10S:0.5T); policultivo com 10 camarões e 1 tilapia m2 (10S:1T); monocultivo com 2 tilápias m2 (2T:0S); policultivo com 2 tilápias e 2,5 camarões m2 (2T:2,5S); e policultivo com 2 tilápias e 5 camarões m2 (2T:5S). Não foi realizada troca de água e nem fornecimento de aeração artificial durante o período experimental, apenas utilizou-se água para completar o volume perdido pela evaporação. O fitoplâncton variou de 78.981 a 303.260 cél.mL-1 e o zooplâncton variou de 470 a 1.421 org.L-1. Os grupos mais frequentes foram Bacillariophyta (fitoplâncton) e Rotífera (zooplâncton). Pode-se concluir que em sistema de policultivo do camarão branco (Litopenaeus vannamei) e a tilápia do Nilo (Oreochromis niloticus) não ocorrem modificações significativas nas densidades do fitoplâncton e zooplâncton em decorrência da alteração das densidades de estocagem do cultivo.

Abstract An experiment was conducted during 95 days to evaluate plankton densities in polyculture of Pacific white shrimp Litopenaeus vannamei and Nile tilapia Oreochromis niloticus. The experiment design was randomized with three treatments and four replicates each. The treatments were as follows: monoculture with 10 shrimps m2 (10S:0F); polyculture with 10 shrimps and 0.5 fish m2 (10S:0.5F); polyculture with 10 shrimps and 1 fish m2 (10S:1F); monoculture with 2 fishes m2 (2F:0S); polyculture with 2 fishes and 2.5 shrimps m2 (2F:2.5S); and polyculture with 2 fishes and 5 shrimps m2 (2F:5S). Neither water exchange nor aeration was provided during the experimental period, only water was used to complete the volume lost by evaporation. The phytoplankton ranged from 78,981 to 303,260 cells.mL-1 and the zooplankton ranged from 470 to 1,421 org.L-1. The most frequent groups were Bacillariophyta (phytoplankton) and Rotifera (zooplankton). In conclusion, in the polyculture system of Pacific white shrimp Litopenaeus vannamei and Nile tilapia Oreochromis niloticus there are no significant changes in the densities of phytoplankton and zooplankton due to the alteration in the culture stocking density.

A 16-week trial was carried out to evaluate an intensive culture system of Litopenaeus vannamei in commercial ponds with zero water exchange. Two management strategies were used: one with the addition of molasses (ML) and the second with commercial probiotic and molasses (PML), each with four replicates. Shrimp L. vannamei (2.09 ± 0.3 g) were stocked in 2.6 ha ponds without liners at a density of 98 shrimp m-2. The commercial probiotics used with molasses was a mixture of Bacillus spp. and Lactobacillus sp. After 16 weeks, no significant differences were found in mean dissolved oxygen, temperature, salinity, pH, total heterotrophic bacteria and zootechnical parameters (yield, FCR, survival and final weight) between the two management strategies. Total ammonia nitrogen concentration (53 to 69%) was the highest inorganic nitrogen compound. There were no significant differences between its concentrations in the two management strategies. The addition of molasses and probiotics are important management strategies for increased shrimp growth in an intensive system in ponds with zero water exchange, however, molasses is cheaper than the probiotics. Molasses inputs were based on a percentage of the daily feed allotments (by weight) and application rates of 30% of total daily feed in combination with commercial probiotics in intensive ponds without liners with zero water exchange was not sufficient to recycle all nitrogen waste with 10 HP ha-1.

Se realizó un estudio de 16 semanas para evaluar el sistema de cultivo de Litopenaeus vannamei en viveros comerciales sin recambio de agua con la adición de melaza y probiótico. Se utilizaron 2 estrategias de manejo: ML (melaza) y PML (probiótico comercial y melaza) con 4 repeticiones en cada caso. Camarones L. vannamei (2,09 ± 0,3 g) fueron sembrados en viveros (2,6 ha sin liner) a una densidad de 98 camarones m-2. La melaza y el probiótico comercial estuvo compuesto por Bacillus spp. y Lactobacillus sp. El oxígeno, temperatura, salinidad, pH, total de bacterias heterótrofas y parámetros zootécnicos (rendimiento, FCR, supervivencia y peso final) no mostraron diferencias significativas entre las estrategias de manejo. La concentración de nitrógeno amoniacal total (53-69%) fue el principal compuesto de nitrógeno inorgánico que se acumuló. La melaza y los probióticos son estrategias de manejo importantes para incrementar el crecimiento del camarón en sistema intensivo sin recambio, sin embargo, la melaza es más económica que los probióticos. La adición de melaza basada en un porcentaje de alimentación diaria (en peso) con tasas de aplicación de 30% del peso del alimento por día y probiótico comercial, en viveros intensivos, sin liners y sin recambio de agua, no fue suficiente para el reciclado de todos los residuos de nitrógeno con 10 HP ha-1..

This study was designed to evaluate the survival of shrimp postlarvae under osmotic stress and its relation with the molt stage. Postlarvae used were in stages PL7 to PL17. Osmotic stress was tested during intermolt stage (IM), initial premuda (PrMI) and final premuda (PrMF), determining its effect on survival. For this analysis the development of PLs gill, individuals weight and water quality parameters were taken into acount. Thirty three treatments in triplicate consisting of 2 factors, moult stages (IM, PrMF and PrMI) and age of postlarvae (PL17 to PL7). The results show significant differences for the interaction molt stage and age. The highest survival was found at the intermolt stage (74.12%) from PL12.

Este estudio fue diseñado para evaluar la supervivencia de poslarvas de camarón sometidas a la prueba de estrés osmótico y su relación con el estado de muda. Se utilizaron poslarvas en los estadios de PL7 a PL17 y sometidas a prueba de estrés osmótico durante la etapa de intermuda (IM), premuda inicial (PrMI) y premuda final (PrMF), determinando su efecto por medio de la supervivencia. Para dicho análisis se tuvo en cuenta el desarrollo branquial de las poslarvas, el peso de los individuos y los parámetros de calidad de agua del cultivo. Se evaluaron 33 tratamientos en triplicado conformados por 2 factores: estadios de muda (IM, PrMI y PrMF) y edad (PL7 hasta PL17). Los resultados indican diferencias significativas para la interacción estadios de muda y edad. La supervivencia más alta se presentó en la etapa de intermuda (74,12%) a partir de PL12.

O objetivo deste trabalho foi avaliar o desempenho de camarão marinho (Litopenaeus vannamei) e tilápia (Oreochromis niloticus) em policultivo, em tanques de cimento, submetido a diferentes densidades de estocagem e estratégias de alimentação, em comparação ao monocultivo. Dois experimentos foram conduzidos, ao mesmo tempo, em delineamento inteiramente casualizado, com três tratamentos e quatro repetições cada um. Os tratamentos do experimento I foram: monocultivo com 10 camarões por m² (10S:0T); policultivo com 10 camarões e 0,5 tilápia por m² (10S:0.5T); e policultivo com 10 camarões e 1 tilápia por m² (10S:1T). O camarão foi a principal cultura, e a alimentação fornecida foi baseada na biomassa de camarão. Os tratamentos do experimento II foram: monocultivo com 2 tilápias por m² (2T:0S); policultivo com 2 tilápias e 2,5 camarões por m² (2T:2.5S); e policultivo com 2 tilápias e 5 camarões por m² (2T:5S). A tilápia foi a principal cultura, e a alimentação fornecida foi baseada na necessidade dos peixes. No experimento I, a introdução da tilápia no cultivo de camarão resultou em baixo crescimento do camarão e baixa taxa de conversão alimentar. No experimento II, a introdução de camarão no cultivo de tilápia não interferiu no desempenho dos peixes. O policultivo é mais eficiente com a combinação de 2 tilápias e 2,5 ou 5 camarões por m² e alimentação baseada na necessidade dos peixes.

The objective of this work was to evaluate the performance of Pacific marine shrimp (Litopenaeus vannamei) and tilapia (Oreochromis niloticus), in a polyculture in tanks subjected to different stocking densities and feeding strategies, in comparison with monoculture. Two experiments were performed, at the same time, in a completely randomized design with three treatments and four replicates each. Treatments for experiment I were: monoculture with 10 shrimp per m² (10S:0T); polyculture with 10 shrimp and 0.5 tilapia per m² (10S:0.5T); and polyculture with 10 shrimp and 1 tilapia per m² (10S:1T). Shrimp was the main crop, and feed was provided based on shrimp biomass. Treatments for experiment II were: monoculture with 2 tilapia per m² (2T:0S); polyculture with 2 tilapia and 2.5 shrimp per m² (2T:2.5S); and polyculture with 2 tilapia and 5 shrimp per m² (2T:5S). Tilapia was the main crop, and feed was provided based on fish requirements. In the experiment I, tilapia introduction to shrimp culture resulted in lower shrimp growth and poor feed conversion rate. In experiment II, shrimp introduction to tilapia culture did not interfere with fish performance. Polyculture is more efficient with the combination of 2 tilapia and 2.5 or 5 shrimp per m² and feed based on fish requirements.