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This paper discusses the similarities between biofilms and periphyton mats in aquaculture systems. The structure of both biofilms and periphyton mats is briefly reviewed, the process of ammonia removal is explained and quantified, solid trapping and detachment from films and mats are described and the possible impact on the oxygen budget in culture systems is examined. In addition, the performance of a recirculating aquaculture system (RAS) using a sedimentation tank and trickling biofilter is compared to the functioning of a periphyton-based RAS.

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A feeding trial was carried out on a shrimp farm located in the Santa Rosa province of El Oro, Ecuador, with four isonitrogenous and isolipidic experimental diets, designed with increasing levels of substitution of fish meal by P. voluvilis, (D-0), 15% (D-15), 25% (D-25), and 50% (D-50). The obtained results indicated that the 50% replacement with P. volubilis in practical diets had no noticeable negative effects on the growth performance of L. vanameii juveniles. The total weight of shrimps fed with 25% and 50% diets (16.04 g and 16.72 g, respectively) and the abdomen weight (10.32 g) of shrimps fed with the D-50 diet were high, with significant differences regarding those fed with the D-0 diet. No adverse effects on muscle composition were found. Significant differences were observed only in groups D-25 (for chymotrypsin) and D-50 (chymotrypsin and alkaline protease). Trypsin and amylase activity was not affected by the inclusion of P. volubilis. The results of this experiment indicated that P. volubilis cake is a possible alternative to fish meal in shrimp feeding; however, it should be studied in more depth to establish the maximum replacement percentage and to identify the adequate treatments to eliminate antinutritional factors.