No abstract

RESUMOA primeira estapa deste trabalho testou a toxicidade de quatro crioprotetores em espermatozoides de Macrobrachium acanthurus durante 10 e 20 min nas concentrações de 10 e 20%. A segunda etapa foi realizar a criopreservação aplicando o crioprotetor com menor grau de toxicidade, testanto dois mecanismos de congelamento, um automatizado (protocolos A e B) e outro convencional (protocolos C e D), durante 24 horas. O protocolo A apresentou velocidade de resfriamento de 0,5°C min -1 até alcançar -32°C, partindo de uma temperatura de -6°C e idem o protocolo B, com a diferença de partir de uma temperatura ambiente; os protocolos C e D apresentaram uma velocidade de resfriamento de 2 e 10°C min -1 , respectivamente, sendo as palhetas transferidas ao nitrogênio líquido. A terceira etapa foi verificar o tempo de vida do espermatozoide quando refrigerado a 5°C. A viabilidade espermática foi avaliada por meio do esfregaço de sêmen com eosina-nigrosina. Os crioprotetores que se apresentaram menos tóxicos foram o glicerol 10 e 20% e metanol 10%, num tempo de equilíbrio de 10 minutos. A melhor velocidade de congelamento foi a de 2°C min -1 para glicerol 10%, com 21,8% de sobrevivência espermática, sendo a refrigeração até três dias recomendada, com uma sobrevivência de 35,3%.Palavras-chave: caridea; criopreservação; crioprotetores; glicerol; metanol; pitú ABSTRACTIn the first part of this study, toxicity tests were performed on the sperm of Macrobrachium acanthurus using four cryoprotectants for periods of 10 and 20 min at concentrations of 10 and 20%. In the second part, cryopreservation was performed by applying the least toxic cryoprotectant, and two freezing methods were tested over 24 hours: automated (protocols A and B) and conventional (protocols C and D). Protocol A exhibited a cooling rate of 0.5°C min -1 from -6°C to -32°C; protocol B was similar to A except for the starting temperature, which was room temperature; whereas protocols C and D exhibited a cooling rate of 2 and 10°C min -1 , respectively. The third part of the study was conducted to assess the lifespan of the sperm when stored at 5°C, in which sperm viability was evaluated by a semen smear with eosin-nigrosin. The least toxic cryoprotectants were 10 and 20% glycerol, and 10% methanol, and the equilibrium time was 10 minutes. The optimal cooling rate was 2°C min -1 for 10% glycerol, which had a sperm survival rate of 21.8%. Cold storage for up to 3 days is recommended, presenting a sperm survival rate of 35.3%.

Farfantepenaeus brasiliensis is a native species in Brazilian coast. It is one of the most exploited marine resources. In order to contribute to the development of techniques to promote the rearing their cultivation, the objective of this study was to evaluate the pink shrimp reproductive performance in captivity under different sex ratios. Breeders were captured in Sepetiba Bay/Brazil and maintained during 107 days in maturation tanks. One hundred and eight animals were randomly distributed into tanks 18 in the proportions 1:1 and 1:2 (M:F). Females have undergone unilateral ablation and identified by markings on their uropods. The evaluation of the reproductive performance was estimated by the number of spawning, fecundity and hatching rate. It was determined optimal size (32,00 mm CL) and minimum weight (24,00 g LW) for reproduction in females. The better fertility and nauplii hatching indicate that the sex ratio 1:2 is most suitable for this species.

The aim of this study was to evaluate the monoculture and polyculture of white shrimp Litopenaeus schmitti and mullet Mugil curema in bioflocs system and clear water. The experimental design was completely randomized in a factorial arrangement (4x2) with four cultures systems (shrimps and fish) and two culture medium (clear water and bioflocs), with four replications: (M50/0) - monoculture L. schmitti density 50 m- 2; (P50/5) – polyculture L. schmitti and M. curema density 50 m-2 and 5 m2, respectively; (P50/10) – polyculture L. schmitti and M. curema density 50 m-2 and 10 m-2 respectively; (M0/10) - monoculture M. curema density 10 m-2. The polyculture of L. schmitti with mullet affected zootechnical performance of shrimp, however, L. schmitti juveniles showed better performance, for all analyzed indexes, when cultured in the bioflocs. The mullet in monoculture and polyculture with lower stocking density (5m-2) showed better final weight , weight gain and specific growth rate than mullet in polyculture with higher density (10m-2) and better performance when cultured in clear water. The bioflocs contributed significantly to shrimp juvenile growth, however fish did not present the same performance in bioflocs system.