Abstract: The goal of this study was to demonstrate the feasibility of culturing the seahorse Hippocampus reidi in an organic integrated multi-trophic aquaculture farm that produces the oyster Crassostrea brasiliana and the shrimp Litopenaeus vannamei. Experiments were conducted to evaluate the effects stocking density and food (natural zooplankton, Artemia nauplii, or both) for the juvenile I, which are fish from 1 to 15 days after birth. Stocking density effect was studied on growth and survival of juveniles II from 30 days to commercial size in net cages. Survival of the juvenile I was not affected by stocking densities from 2 to 5 ind L-1 and was greater than 70% in all treatments. Seahorse length, however, was inversely related to stocking density. Both treatments with wild zooplankton promoted higher seahorse survival and growth than diet composed exclusively by Artemia sp. during the first 15 days of life. Juvenile II growth decreased with stocking density from 5 to 40 ind m-3 but survival was not affected by it. The total benefit and proportion of colored animals increased significantly with stocking density. The present study confirms the technical feasibility of organic multi-trophic seahorse production in net cages. Even at the highest density tested the seahorses grew well and could generate high profits.

Resumen: El objetivo del estudio fue demostrar la viabilidad del cultivo del caballito de mar Hippocampus reidi, en un sistema orgánico de acuicultura multitrófica integrada, compuesta por cultivos de ostra Crassostrea brasiliana y camarón Litopenaeus vannamei. Se realizaron experimentos para evaluar los efectos de la densidad poblacional y la dieta (zooplancton natural, nauplii de Artemia sp., o ambos), en juveniles I, que corresponde de 1 a 15 días después del nacimiento. Se estudió el efecto de la densidad poblacional en el crecimiento y la supervivencia de juveniles II a partir de 30 días hasta el tamaño comercial en jaulas de malla. La supervivencia de la etapa juvenil I no fue afectada por densidades poblacional de 2 a 5 peces L-1 y fue mayor al 70% en todos los tratamientos. El tamaño de los caballitos de mar, sin embargo, estuvo inversamente relacionado con la densidad poblacional. Ambos tratamientos, con zooplancton silvestre, promovieron una mayor supervivencia y crecimiento del caballito de mar que la dieta solo compuesta de Artemia, esto durante los primeros 15 días de vida. El crecimiento de juvenil II disminuyó con la densidad poblacional de 5 a 40 peces m-3 y la supervivencia no fue afectada. El beneficio total y la proporción de animales coloridos aumentaron significativamente con la densidad poblacional. Se confirma la viabilidad técnica de la producción de caballitos de mar multitróficos orgánicos en jaulas de malla, incluso en la densidad más alta probada en este estudio los caballitos de mar crecieron normalmente, lo que podría generar buenos rendimientos económicos.

Visando o uso futuro do copépodo marinho bentônico Tisbe biminiensis em bioensaios toxicológicos de sedimentos na fase sólida, o presente estudo investigou o efeito do sedimento lamoso do estuário de Maracaípe (Nordeste do Brasil). Foram considerados a granolometria e o tóxico de referência dicromato de potássio sobre a espécie. O sedimento lamoso de Maracaípe pode ser usado como controle, uma vez que não interfere no ciclo de vida do copépodo e possui níveis de contaminação de metais que não causariam efeitos biológicos em invertebrados bentônicos. Nem a sobrevivência ou fecundidade foi afetada pelo tamanho do grão, sugerindo que esta espécie pode ser usada com qualquer tipo de sedimento, de lama a areia. A sensibilidade de T. biminiensis ao K2Cr2O7 em testes agudos foi similar a de outros organismos. Os valores de CL50 (concentração letal a 50% dos organismos) para T. biminiensis foram em média 7,51, 4,68 e 3,19 mg L-1 para o Cr em 48, 72 e 96h, respectivamente. Estes resultados sugerem que T. biminiensis é um organismo promissor para uso em avaliações de toxicidade com a fase sólida do sedimento.

For the future use of the marine benthic copepod Tisbe biminiensis in solid-phase sediment toxicological bioassays, the present study investigated the effect of muddy sediment from the Maracaípe estuary (northeastern Brazil), sediment particle size and the reference toxicant potassium dichromate on the species. Muddy sediment from Maracaípe can be used as control sediment, since it does not interfere in the copepod life-cycle and has metal contamination levels that are unlikely to produce any detrimental biological effects on benthic invertebrates. Neither survival nor fecundity was affected by grain size, suggesting that this species can be used with any kind of sediment from muddy to sandy. The sensitivity of T. biminiensis to K2Cr2O7 in acute tests was similar to that of other organisms. The LC50 (lethal concentration to 50% of the test organisms) medium values for T. biminiensis were 7.51, 4.68 and 3.19 mg L-1 for Cr in 48, 72 and 96 h, respectively. These results suggest that T. biminiensis is a promising organism for use in solid-phase sediment toxicity assessments.