Study the effect of low pH on Ruditapes decussatus (Mollusca: Bivalvia)

The grooved carpet shell clam (Ruditapes decussatus) is one of the most economically essential mollusks in Mediterranean lagoons and sandy beaches, with fisheries and aquaculture both contributing to its abundance. The goal of this research is to see how varying amounts of acidity affect this calcifying organism. 420 ppm (ambient control), 550 ppm, 750 ppm, and 1050 ppm were used to incubate juvenile clams in CO2 enriched saltwater. With increasing pCO2 , the biological parameters evaluated revealed a small decline. Differences, however, were not substantial. In terms of overall weight, the reduction was greatest at 550 and 1050 ppm. Furthermore, clams kept at 550 parts per million had the lowest condition index and the greatest mortality rate of 8%. Both the 550 ppm and the control 420 ppm groups demonstrated an increase in metabolic rate and ammonia excretion in the physiological response testing. With increasing acidification, the algal feed clearance rate declined, with the highest average value in the control (420 ppm) group and the lowest average value in the extremely high pCO2 (1050 ppm) group. Ocean acidification may put further strain on R. decussatus' health and economic value by the end of the century

USING OF BIOTESTING IN SAFTY ASSESMENT OF THE EXTRUDED FEED ADDITIVE WITH ALGAE

The article is devoted to the problems of determining quality and safety of extruded feed additive (EFA) with algae. It is used in the production of mixed feed and premixes. It is proved that the safety of finished food products depends on the safety of feed and feed raw materials. The list of conditions for obtaining safe finished products is given. Today traditional methods of analytical chemistry, express and toxicological methods (marking, biotesting) are used for the analysis of feed safety. The expediency of use of brown algae in the composition of feed products is substantiated. The brightest representative ofbrown algae is Laminaria. The technology of using Laminaria algae in the composition of feed products in the form of extruded feed additive is proposed. The method of determination of organicity by methods of biotesting is given: biocrystallization method, determination of the oxidation-reduction potential index (ORP), organicity using Colpoda steinii culture. Indicators of organicity are given. An analysis of experimental samples biocrystalograms suggests that EFA is environmentally safe and do not endanger the environment or the health and life of animals and humans. When determining the ORP of the EFA with algae it was established that the product is easily digestible, since it has a biological compatibility with the animal organism. The expediency of using the process of extrusion to reduce the toxicity of algae is established. The application of the extrusion allows to add up to 15% Laminaria algae to the feed. The results of biological studies of EFA in vivo are presented, which indicate a high biological efficiency of the use of algal feed supplement in the composition of feed for young farm birds in the amount of up to 25%, since the average daily weight gain of rats increases and the cost of feed decreases.