Marco A. Porchas-Cornejo

Evaluation of three feeding strategies on the culture of white shrimp penaeus vannamei Boone 1931 in low water exchange ponds

Abstract Three feeding strategies (feeding tables (FTA), feeding trays (FT) and complementation of natural food (CNF)) for white shrimp farmed in earthen ponds were evaluated in an experimental study conducted during 15 weeks at Bahia Kino, Sonora, northwestern Mexico. Significant differences ( p p > 0.05). The lowest feed conversion ratio (FCR) was 1.59:1, obtained in treatment CNF. It was not significantly different ( p > 0.05) from that obtained in treatment FT (1.69:1). Both were better than the FCR observed in treatment FTA: 2.39:1. Morning dissolved oxygen was significantly lower in treatment FTA ( p p Penaeus vannamei .

Effect of aeration rate on growth, survival and yield of white shrimp Penaeus vannamei in low water exchange ponds

A study was conducted in Bahia Kino, Sonora, northwest Mexico, to evaluate the effect of aeration rate on the growth, survival and yield of the white shrimp Penaeus vannamei farmed in ponds with reduced water exchange. Aeration rates of 0, 6, 12 and 24 h per day were tested. No significant differences in growth rate were detected among treatments. Survival and yield were significantly higher in ponds with 12 and 24 h of aeration.

Production response and digestive enzymatic activity of the Pacific white shrimp Litopenaeus vannamei (Boone, 1931) intensively pregrown in microbial heterotrophic and autotrophic-based systems.

Shrimp postlarvae were reared into different microcosm systems without water exchange; a traditional system based on simple fertilization to improve microalgae concentration (control), an autotrophic system (AS) based on the promotion of biofloc and biofilm by the addition of fertilizer and artificial substrates and a heterotrophic system (HS) based on the promotion of heterotrophic bacteria by the addition of nitrogenous and carbonaceous sources and artificial substrates. Better growth performance and survival were registered in shrimp from the AS and HS compared to the control. Feed conversion ratios were below 0.7 for all treatments, but AS and HS were significantly lower than the control. Regarding digestive performance, no significant differences were observed for trypsin, amylase and lipase activities among AS and control shrimp; however, shrimp from HS showed a higher trypsin and amylase activities, suggesting a higher digestive activity caused by the presence of microbial bioflocs. The presence of biofilm and bioflocs composed by either autotrophic or heterotrophic organisms in combination with formulated feed improved the growth performance and survival of shrimp. Apparently, such combination fits the nutritional requirements of shrimp.

Bacterial biota of shrimp intestine is significantly modified by the use of a probiotic mixture: a high throughput sequencing approach

The use of probiotics is a common practice of current shrimp aquaculture. Despite the immunophysiological responses that have been measured in shrimp exposed to probiotics, no information is currently available on the effect of this practice on the intestinal microbiota. The objective of this work was to evaluate the effect of a probiotic mixture on the intestinal microbiota of shrimp cultured under farm conditions. A culture-independent method based on high-throughput-sequencing (16S rRNA) was used to examine intestinal bacterial communities. A traditional system (without probiotics) was used as the reference. Targeted metagenomics analysis revealed that the probiotic mixture was based on bacteria in the phyla Proteobacteria and Firmicutes. A total of 23 species of bacteria were detected in the probiotic mixture; of these, 11 were detected in the intestine of shrimp reared in both systems, and 12 were novel for the system. Eight of the novel species were detected in shrimp cultured with the probiotic mixture; however, none of these novel species were related to marine or inclusively aquacultural environments, and only one (Bacillus subtilis) was recognized as probiotic for shrimp. The use of the probiotic mixture modified the bacterial profile of the shrimp intestine; however, most of the bacteria incorporated into the intestine were nonindigenous to the marine environment with no previous evidence of probiotic effects on any marine organism. The use of this probiotic mixture may represent a risk of causing environmental imbalances, particularly because farms using these types of probiotic mixtures discharge their effluents directly into the ocean without prior treatment.

Bioremediation of Aquaculture Effluents

Aquaculture has been accused of being a pollution promoter of aquatic environments. Bioremediation systems have been proposed to mitigate the environmental impact caused by aquaculture wastes. Autotrophic and heterotrophic microbes have been extensively used for bioremediation of metals, petroleum spills, and their derivatives. However, the use of microbes to bioremediate aquaculture wastes has not been as extensive. The particular wastes generated by aquaculture, such as nitrogenous and phosphorous inorganic compounds, organic matter, and etcetera, require the use of specific microbes. This chapter aims to present and discuss the role of different microbes on the bioremediation of aquaculture wastes.

Immunophysiological Response of Pacific White Shrimp Exposed to a Probiotic Mixture of Proteobacteria and Firmicutes in Farm Conditions

AbstractThe effect of a probiotic mixture (Proteobacteria–Firmicutes) on the immune and physiological responses of Pacific white shrimp Litopenaeus vannamei reared at commercial scale was evaluated. Shrimp were cultured into two different systems: a traditional system and a probiotic-based system using the probiotic mixture every day of culture. Hemolymph parameters and the expression of immune-related genes were monitored during the culture cycle. Shrimp reared in the probiotic-based system registered an upregulation of clotting protein (CP), prophenoloxidase (proPO), alpha-2-macrogolbulin (A2M), superoxide dismutase (SOD), and heat shock protein (hsp) 60 genes in hemocytes compared with those reared in the traditional system. Also, high transcription levels of CP, proPO, transglutaminase, beta glucan binding protein, SOD, hsp60, and hsp90 genes were detected in the hepatopancreatic tissue of shrimp reared with probiotics. While no significant differences were detected for hemolymphatic concentrations of...