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The reproductive cycle of Xiphopenaeus kroyeri north-eastern Brazil was described to contribute to the sustainable management of this stock in the region. Specimens were collected monthly from August 2011 to July 2012 using a local vessel of the artisanal fleet. A total of 1201 individuals were analyzed (673 females and 528 males) with a mean carapace length (CL) of 1.88 ± 0.16 cm and total length (TL) of 9.00 ± 1.22 cm. The lowest CL and TL of mature females were 1.33 and 6.5 cm, respectively, and all females above 2.44 cm (CL) and 11.5 cm (TL) were mature. Ovarian maturation was classified into four stages: I (immature), II (maturing), III (mature) and IV (spawned). Individuals of all maturational stages were present throughout the year. Considering the macro and microscopic analysis, it was suggested that this species in north-eastern Brazil has a continuous reproductive cycle, with two seasonal peaks, November/December and February (austral spring and summer). A positive correlation between the percentage of mature females and temperature was observed, and a higher percentage was reported in the warmer months of the year. This suggests that the reproductive peaks can be triggered by water temperature variation throughout the year. [ABSTRACT FROM AUTHOR]

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The article focuses on a study which examined the technical feasibility of biofloc culture rearing system (BFT systems) in Brazil. A greenhouse with high density polyethylene (HDPE)-lined tanks was used in this study, while Aquatec™ was the source of the Litopenaeus vannamei post-larvae. Results of the study showed that there were significant differences among stocking density treatments. It also found lower weight and survival for the shrimp cultured at the higher stocking density.

Copyright of Brazilian Journal of Agricultural Sciences / Revista Brasileira de Ciências Agrárias is the property of Universidade Federal Rural de Pernambuco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Morphometric relationships of length–length (carapace and total body length) and length–weight (wet body weight) were analyzed during nursery, grow out, and broodstock production phases of Farfantepenaeus paulensis ranging in size from 0.06 to 60 g (n=2969). Morphometric data during the broodstock production phase were pooled for males and females, as no significant differences in regression lines between sexes were observed. Shrimp from the broodstock production phase tended to have longer and heavier bodies compared with grow out individuals with the same carapace length. Increments on body weight (BW) were proportional to total length (TL) rather than carapace length for nursery, grow out, and broodstock. Conversion equations relating the measures of length and weight are provided for each culture phase. The use of a general morphometric relationship between total length and body weight (BW=0.07×10−3 (TL)3.058) is recommended to simplify the management in different culture phases of F. paulensis in southern Brazil. [Copyright &y& Elsevier]

Culture potential of the native pink shrimp, Farfantepenaeus paulensis, and exotic Pacific white shrimp, Litopenaeus vannamei, was analyzed in extreme southern Brazil. The experiment was conducted at the Marine Aquaculture Station, University of Rio Grande, Rio Grande do Sul State. After nursery, pink shrimp (0.16 g) and Pacific white shrimp (0.17 g) juveniles were transferred to a 450 m2 earthen pond internally divided into six circular (21 m2 each) experimental pens. Pens were randomly assigned to a treatment (pink shrimp or Pacific white shrimp) and stocked at 15 shrimp/m2. Shrimp growth was monitored during 102 days in the summer. Feed was composed of a commercial diet and a fresh frozen mixture (fish and crustacean). After 30 days of culture, Pacific white shrimp showed significantly higher increases in mean weight, reaching at-harvest weight of 12.52 g compared to 11.17 g for pink shrimp. Water quality parameters presented optimal growing conditions for both species, except for lower temperatures (19°C) during the last two weeks of culture, which resulted in a drastic decrease in the growth rate of Pacific white shrimp. These results indicated a better tolerance for lower water temperatures on the part of shrimp. Although the lower temperatures resulted in a reduced number of cycles (1 or 2 per year), the estimated yield for pink shrimp (1,451 kg/ha) and Pacific white shrimp (1,790 kg/ha) suggested that the production per cycle in extreme southern Brazil is comparable to that in the other Brazilian States. Despite the more favorable results for Pacific white shrimp, the culture of pink shrimp is also recommended, but further studies are necessary to improve its growth performance under culture. [ABSTRACT FROM PUBLISHER]

Shrimp farming has a great ecological, economic, and social importance in northeastern Brazil. Although the conventional farming system is widely used, biofloc technology (BFT) system has been developed to reduce environmental impacts and optimizing the production. Thus,the present study evaluated the technical efficiency of production cycles of Litopenaeus vannamei in conventional and BFT systems.We analyzed 48 production cycles in the conventional system in 2013 and 2014 and 9 cycles in the BFT system in 2014 through data envelopment analysis (DEA). The inputs corresponded to the population density (post-larvae m-2), amount of feed (kg ha-1 cycle-1), labor (man ha-1) and power supply (HP ha-1), whereas the yield (kg ha-1 cycle-1) was considered the output. The results indicated four production cycles (7.0%) technically efficient, three in the conventional system and one in the BFT. By comparing the productive systems, there was significant difference in their mean scores of technical efficiency. There was a greater influence of the management inefficiency on the conventional system, while the production scale reduced the average scores of technical efficiency in the BFT system. These results may help to improve the development of sustainable L. vannamei farming in both systems by reducing waste and increasing profits.