We provide a global overview of the intestinal bacteriome of Litopenaeus vannamei in two rearing systems and after an oral challenge by the White spot syndrome virus (WSSV). By using a high-throughput 16S rRNA gene sequencing technology, we identified and compared the composition and abundance of bacterial communities from the midgut of shrimp reared in the super-intensive biofloc technology (BFT) and clear seawater system (CWS). The predominant bacterial group belonged to the phylum Proteobacteria, followed by the phyla Bacteroidetes, Actinobacteria, and Firmicutes. Within Proteobacteria, the family Vibrionaceae, which includes opportunistic shrimp pathogens, was more abundant in CWS than in BFT-reared shrimp. Whereas the families Rhodobacteraceae and Enterobacteriaceae accounted for almost 20% of the bacterial communities of shrimp cultured in BFT, they corresponded to less than 3% in CWS-reared animals. Interestingly, the WSSV challenge dramatically changed the bacterial communities in terms of composition and abundance in comparison to its related unchallenged group. Proteobacteria remained the dominant phylum. Vibrionaceae was the most affected in BFT-reared shrimp (from 11.35 to 20.80%). By contrast, in CWS-reared animals the abundance of this family decreased from 68.23 to 23.38%. Our results provide new evidence on the influence of both abiotic and biotic factors on the gut bacteriome of aquatic species of commercial interest.

O objetivo deste trabalho foi avaliar o uso de suplemento prebiótico, probiótico e simbiótico, na dieta de camarões marinhos (Litopenaeus vannamei) e seus efeitos sobre o crescimento, a microbiota intestinal, a resposta imune e a resistência ao desafio experimental com Vibrio alginolyticus. Foram utilizados quatro tratamentos: prebiótico inulina; probiótico Lactobacillus plantarum; simbiótico Lactobacillus plantarum + inulina; e controle. Os camarões foram distribuídos em 16 tanques de dez mil litros de água, povoados com 200 camarões cada, cultivados por seis semanas. Avaliaram-se a microbiologia do trato intestinal dos camarões e a reposta imune, antes e após o desafio com V. alginolyticus. A concentração de Vibrio spp. no trato digestório foi menor em camarões alimentados com dieta suplementada com prebiótico, probiótico e simbiótico, enquanto a concentração de bactérias acidoláticas foi superior somente nos camarões alimentados com probiótico e simbiótico. O título aglutinante do soro contra V. alginolyticus aumentou no grupo probiótico e simbiótico, antes da infecção, e foi maior em todos os tratamentos após infecção com V. alginolyticus, em comparação ao controle. Não foi observada diferença entre os tratamentos quanto aos demais parâmetros avaliados. As dietas probióticas, prebióticas e simbióticas alteram a microbiota intestinal e aumentam o título aglutinante do soro contra V. alginolyticus; contudo, não alteram a resistência ao desafio nem o crescimento dos camarões.

A study was conducted to test the inclusion of Aurantiochytrium sp. meal in the rearing of Penaeus vannamei grown in a clear water system and at a suboptimal temperature of 22 °C. The doses tested were 0 (control), 1, 2, 3, and 4% at a stocking density of 100 shrimp/m³. Rearing was carried out with aeration and individual heaters, and seawater temperature was controlled with a chiller. After nine weeks, shrimp were weighed and hemolymph was collected for hemato-immunological tests, and growth performance were calculated. Shrimp raised at 22 °C and fed a 1% of dietary supplementation of Aurantiochytrium sp. meal were superior in immunological parameters. After the dietary assay, a total of 42 shrimps (10.9 ± 0.06 g) per treatment were infected with White Spot Syndrome Virus (WSSV). They were orally infected with 2.6 ± 10⁶ virus particles per g of the animal, maintained at a suboptimal temperature of 22 °C for 108 h, and acclimated to an optimal temperature of 28 °C for an additional 48 h. At 7 days post infection, surviving shrimp were collected for hemato-immunological analysis. Cumulative mortality results showed that shrimp fed diets containing 3% and 4% Aurantiochytrium sp. meal had higher survival than other treatments when challenged with WSSV.

This paper reports the evaluation of digestibility, immunological parameters, and resistance to thermal shock at low temperature in Litopenaeus vannamei fed diets with diferent Aurantiochytrium sp. meal additions (0; 0.5; 1 and 2%). First, the apparent digestibility coefficient of the ingredient was determined. The digestibility of the microalgae meal was high for protein (74.90%); around 60% for lipids, and for docosahexaenoic fatty acid (DHA) it was 55.61%. After, shrimp rearing with the feed additive was carried out in a clear water system, containing 25 shrimp (initial weight: 4.89 ± 0.27 g) per 400 L tank. Feeding occurred four times a day. After a three-week period, immunological parameters were evaluated and thermal shock was performed. Animals fed 0.5% and 2% of the microalgae Aurantiochytrium sp. showed higher survival to thermal shock. In immunological analyses, the serum agglutiniting titer was higher (p <0.05) in the 0.5 and 2% additions of the microalgae meal, and the phenoloxidase activity (PO) was higher in the 1% addition (p <0.05). It is concluded that there is good utilization of the nutrients of Aurantiochytrium sp. meal by L. vannamei and its addition to the diet (0.5 and 1%) increased shrimp resistance to thermal shock.

This study aimed to evaluate the effect of the continuous use of the settling chamber for solids removal in the cultivation of the marine shrimp Penaeus vannamei and the halophyte Salicornia neei in an aquaponic system with bioflocs. Two treatments were tested: with settling and without settling. Each experimental unit consisted of an 800 L tank for shrimp rearing (stocking density of 375 shrimp m⁻³) and a hydroponic bench of 0.33 m² for 28 seedlings (84 plants m⁻²). In the treatment without settling, water was continuously pumped to the hydroponic bench. In the treatment with settling, the water was first pumped to the chamber, and the overflow was then distributed across each irrigation channel, returning to the tank by gravity. To maintain the concentration of suspended solids in the shrimp culture, solids that accumulated in the settling chamber were pumped back into the tank every 30 min. During the 54-day trial, the reduction in suspended solids in the treatment with settling led to an increase in TAN and NO₂ levels, while the concentration of NO₃ remained stable. Although water quality parameters were more stable in the treatment without settling, no significant differences were observed between the treatments regarding plant and shrimp production indices. These results demonstrate the feasibility of cultivating P. vannamei and S. neei in a biofloc-based aquaponic system without the continuous use of a settling chamber during the pre-grow phase (until 10 g), offering a potential method for simplifying aquaponic system design.