Wilson Wasielesky Junior

The anesthetic efficacy of eugenol and the essential oils of Lippia alba and Aloysia triphylla in post-larvae and sub-adults of Litopenaeus vannamei (Crustacea, Penaeidae)

The aim of this study was to evaluate the anesthesia induction and recovery times of sub-adult and post-larvae white shrimp (Litopenaeus vannamei) that were treated with eugenol and the essential oils (EOs) from Lippia alba and Aloysia triphylla. Oxidative stress parameters in the hemolymph of this species were also analyzed. The concentrations of eugenol, A. triphylla EO and L. alba EO recommended for anesthesia were 200, 300 and 750 μL L(-1) for sub-adults and 175, 300 and 500 μL L(-1) for post-larvae, respectively. The concentrations studied during the transport of sub-adults were between 20 and 50 μL L(-1) eugenol, 20-30 μL L(-1)A. triphylla EO and 50 μL L(-1)L. alba EO. For post-larvae, the optimal concentrations for transport were 20 μL L(-1) eugenol and between 20 and 50 μL L(-1)A. triphylla EO. The white shrimp sub-adults that were exposed to A. triphylla EO (20 μL L(-1)) showed increases in their total antioxidant capacities (150%), catalase (70%) and glutathione-S-transferase (615%) activity after 6 h. L. alba EO (50 μL L(-1)) and eugenol (20 μL L(-1)) also increased GST activity (1292 and 1315%) after 6 h, and eugenol (20 μL L(-1)) decreased the total antioxidant capacity (100%). Moreover, concentrations above 30 μL L(-1) for the EOs of A. triphylla and L. alba and 20 μL L(-1) eugenol were effective at inducing anesthesia and improving the antioxidant system against reactive oxygen species (ROS) after 6 h.

Perspectivas para o desenvolvimento dos cultivos de camarões marinhos no estuário da Lagoa dos Patos, RS

Shrimp production in Brazil has presented a significant increase in the last few years, especially in the northeastern region. Although climatic conditions in southern Brazil do not allow year-round production, considerable investments have been made in the region. In the estuarine area of Patos Lagoon, the culture of the native Farfantepenaeus paulensis in cages and pen enclosures, and of Litopenaeus vannamei in earthen ponds are being developed as new activities that will certainly produce social and economical development to the region. Nevertheless, the implantation of shrimp farming without proper ordination and control may generate serious environmental problems. The present paper presents an overview of the environmental characteristics of the area and describes the farming systems currently adopted. Furthermore, the main challenges faced by this new activity, such as the discussion of a legislation adapted to local conditions, and the definition of areas appropriate for farming are presented. Finally, the sustainable development of shrimp farming is discussed under social, economical and environmental perspectives.

Efeito da densidade de estocagem sobre o biofilme e o desempenho de pós-larvas do camarão-rosa FarfantePenaeus paulensis cultivadas em gaiolas

O objetivo deste estudo foi analisar a influencia da densidade de estocagem na sobrevivencia e no crescimento de pos-larvas de F. paulensis cultivadas em gaiolas durante a fase de bercario. Alem disso, foram identificados e quantificados os principais microrganismos presentes no biofilme formado nos substratos artificiais colocados dentro das gaiolas. Foram usadas gaiolas com 4 m2 de fundo e com substratos artificiais, nas densidades de 100, 200, 300, 400 e 500PL25 m-2. O experimento durou 35 dias. Observou-se uma relacao negativa entre o aumento da densidade de estocagem de camaroes e a sobrevivencia e o crescimento destes. Foi observada uma preferencia pelo consumo de diatomaceas centricas. A viabilidade tecnica do cultivo de F. paulensis em gaiolas foi confirmada. O cultivo de F. paulensis em gaiolas na fase de bercario pode ser feito em densidades de ate 400PL m-2, sem maiores perdas em sua sobrevivencia e seu crescimento.

Análise comparativa da criação dos camarões-rosa Farfantepenaeus brasiliensis e FarfantePenaeus paulensis criados em gaiolas em ambiente estuarino

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.

Viabilidade do cultivo do camarão-rosa Farfantepenaeus paulensis (Crustácea, Decapoda) em gaiolas sob diferentes densidades durante o outono no sul do Brasil

Neste trabalho, foi estudada a possibilidade de cultivar o camarao-rosa Farfantepenaeus paulensis em gaiolas com diferentes densidades de estocagem durante o outono (abril a junho) no estuario da Lagoa dos Patos, RS. Juvenis com peso medio de 4,95g (± 1,69 dp foram estocados em gaiolas nas densidades de 20, 40, 80, 100 e 120 ind/m2. Os camaroes foram alimentados diariamente ad libitum com pedacos de Corvina (Micropogonias furnieri). As sobrevivencias e os pesos foram observados nos tempos 20, 40 e 60 dias de experimento. Durante o periodo de cultivo a temperatura da agua decresceu de 24 para 11°C (media = 17,1°C) e a salinidade oscilou entre 3 e 26 (media = 17,5). As taxas de sobrevivencia nas densidades de 20, 40, 80, 100 e 120 ind/m2 foram 65%, 68%, 46%, 52% e 43,3% respectivamente, sendo significativamente maiores nas densidades de 20 e 40 ind/m2. Apos 60 dias, os camaroes estocados em 20 e 40 ind/m2 atingiram peso superior a 8,0g, sendo significativamente maiores (P<0,05) que nos demais tratamentos. A maior biomassa (356g) foi obtida na densidade de 120 ind/m2. Foram produzidos de 250 a 350g de camaroes com peso medio de 6,5 a 8,0g por m2, mesmo em altas densidades de estocagem (40 a 120 ind/m2). As taxas de sobrevivencia dos camaroes mantidos em 20 e 40 ind/m2 podem ser consideradas satisfatorias, contudo, apos a temperatura ficar abaixo de 18°C, as taxas de crescimento foram reduzidas. Os resultados confirmam o efeito negativo da densidade de estocagem sobre o crescimento dos camaroes, sendo recomendada a estocagem de 40 a 120 juvenis/m2. Foi, contudo, comprovada a possibilidade de cultivar F. paulensis durante o outono no sul do Brasil.

The influence of water renewal rates on the reproductive and molting cycles of Penaeus paulensis in captivity

O presente estudo foi proposto para analisar a reproducao de um estoque selvagem de Penaeus paulensis em relacao ao seu ciclo de mudas. O desenho experimental foi composto por dois tratamentos em duplicata (fluxo continuo e com renovacao). A densidade de estocagem nos tanques experimentais (1,50 x 0,96m) foi de aproximadamente 7 camaroes/m2, resultando em 4 machos (23,9 ± 2,3 g) e 6 femeas (52,0 ± 5,5 g) por tanque. Os camaroes tiveram seus uropodos cortados para marcacao individual e a maturacao das femeas foi induzida por ablacao unilateral do pedunculo ocular. O periodo intermuda de femeas e machos (17,4 ± 3,2 e 17,8 ± 4,6 dias, respectivamente), numero de dias entre a muda e primeira desova (6,9 ± 2,8 dias) e numero de desovas no periodo intermuda (1,4 ± 0,5), nao apresentaram diferencas significativas (P>0,05) entre os tratamentos. Nenhuma influencia no ciclo de muda ou nos parâmetros de performance reprodutiva foram relacionadas a diferencas na qualidade de agua, principalmente no que se refere aos compostos nitrogenados, sugerindo uma reducao nas taxas de renovacao de agua em sistemas de maturacao. Contudo, uma diminuicao no numero de ovos por desova foi observado. Este fato parece estar associado as pequenas dimensoes dos tanques utilizados. Os resultados do ciclo de muda de P. paulensis podem ser uteis para o acompanhamento e melhor planejamento da reproducao desta especie em cativeiro.

Effect of salinity on performance and body composition of Pacific white shrimp juveniles reared in a super-intensive system

The objective of this study was to evaluate the effect of salinity on the culture water quality, performance and body composition of Litopenaeus vannamei juveniles (1.16±0.30 g) reared for 36 days in a super-intensive system without water exchange at salinities of 4, 16 and 32‰. Groups of 200 animals (140/m2) were stocked, with three replicates, in nine fiber-cement tanks (1.11 × 1.29 × 0.70 m) with a useful volume of 400 L. Physical and chemical parameters of water, such as temperature and dissolved oxygen before and after midday, pH, alkalinity, total suspended solids, total ammonium nitrogen, nitrite, nitrate, and phosphate, were monitored. Performance parameters like survival, weight gain, specific growth rate, feed conversion ratio and protein retention rate, were also evaluated. The proximate composition of the juveniles was analyzed through the moisture, protein, lipid and ash contents. The physical and chemical parameters of the water were influenced by the treatments. The increased salinity produced a significant increase in the alkalinity and the concentrations of total suspended solids, nitrite and phosphate. Of the parameters that were examined to evaluate the performance and proximate composition of the shrimp, only survival, protein retention rate and body lipid content were significantly influenced. The highest values were found at a salinity of 32‰. However, the analysis of the proximate composition of the bioflocs showed that the moisture, protein and lipid contents increased as the salinity decreased. Growth, use of feed and survival of L. vannameijuveniles reared in a super-intensive system without water exchange is positively influenced by an increase of salinity from 4 to 32‰.

Antioxidant and oxidative damage responses in different organs of Pacific white shrimp Litopenaeus vannamei (Boone, 1931) reared in a biofloc technology system

Shrimp (Litopenaeus vannamei) reared in a conventional seawater (SW) aquarium system SW were compared with those raised in a biofloc technology (BFT) system. After 30 days, the L. vannamei shrimp were euthanized and samples of gills, hepatopancreas and muscle were dissected. Statistical analysis was performed using bi-factorial ANOVA, with the factors of the treatment (shrimp reared in SW or in a BFT system) and organs (gills, hepatopancreas and muscles). No differences (p > 0.05) in glutathione-S-transferase activity were observed between shrimp reared in SW and shrimp reared in BFT (p < 0.05). Glutathione levels were lower (p < 0.05) in the gills and hepatopancreas of shrimp reared in the BFT system, suggesting changes in the antioxidant composition of these organs. Lipid peroxidation levels were higher in the hepatopancreas than in muscle in shrimp reared in SW (p < 0.05) and this difference was not observed in organisms reared in the BFT system (p > 0.05). Overall, the results showed that rearing shrimp in the BFT system altered both their antioxidant and oxidative damage responses. This indicates that some microbial communities in BFT systems can influence the redox state of L. vannamei.

Avanços da maricultura na primeira década do século XXI: piscicultura e carcinocultura marinha

Marine fish culture is still in its infancy in Brazil. For several years the snook Centropomus parallelus and the flounder Paralicithys orbignyanus were considered for aquaculture, but their commercial application has not yet been achieved. However, once technology for culture of cobia Rachycentron canadum became available, several private companies showed interest for marine fish culture. Besides traditional rearing technologes, cobia is suitable for open ocean culture in cages. This species shows fast growth rates, fish can achieve 4 or 8 kg within one year of age and its flesh is highly appreciated. Shrimp farming has been questioned for environmental issues, use of fish oil and fish meal, and spreading diseases. Rearing shrimp in systems without water exchange, know as ZEAH (Zero Exchange Aerobic Heterotrophic Culture systems) or bioflocs applies methods that minimize these problems, contributing for the development of sustainable shrimp farming.

Polyculture of Litopenaeus vannamei shrimp and Mugil platanus mullet in earthen ponds

The objective of the present study was to evaluate the growth performance of the shrimp Litopenaeus vannamei and the mullet Mugil platanus in earthen ponds (200 m²) located in the Laboratory of Continental Aquaculture of Universidade Federal do Rio Grande (FURG), in both polyculture and monoculture systems. The study consisted of three replicates, as follows: shrimp monoculture (SM), shrimp and mullet polyculture (PO) and mullet monoculture (MM). The stocking density was 10 post-larvae shrimp (PL) m−2 and 0.67 mullet m−2. Fish and shrimp were fed commercial shrimp meal (38% crude protein) once a day. Initially, the amount of feed to shrimp was 20% of their total biomass which was later reduced to 5%. Mullets were fed at 5% of their stocked biomass. The experiment lasted 79 days during the summer of 2007/2008. At harvest, shrimp in monoculture had weight gain (15.59 g), specific growth rate (8.40% day−1), apparent feed conversion (0.88), survival (91%) and production (1.454 kg ha−1) significantly higher than in polyculture (1.039 kg ha−1). Mullets in polyculture had significantly better weight gain (42.72 g) and specific growth rate (3.99 % day−1) than those in monoculture (31.04 g and 3.69% day−1, respectively), while the mullet condition factor was significantly smaller in polyculture (1.06) than in monoculture (1.13). The apparent feed conversion of the mullets did not present significant differences between monoculture (2.50) and polyculture (2.40). The physical and chemical water parameters were not significantly different in any of the experiments, except for the transparency, which was higher in earthen ponds with mullet monoculture. Polyculture of shrimp and mullet reared together in earthen ponds negatively affects the shrimp production and favors the production of mullets.