Pelleted diet with thermal treatment of ingredients for Octopus americanus: Growth performance and enzymatic activity

The octopuses are an emergent group for marine aquaculture diversification. One of the main factors limiting their commercial production is the absence of pelleted or extruded diets that are capable of promoting adequate survival and growth. We tested a pelleted diet with ingredients dried at 40 degrees C and a semi-moist diet based on of raw ingredients (control diet) on the growth performance and activity of digestive enzymes in Octopus americanus subadults. Compared to the semi-moist diet, the pelleted diet was well accepted and presented greater stability in the water and lower leaching. Both diets provided similar growth, survival, feed efficiency and conversion rates, although the total ingestion rate and protein and energy intake rates were higher in octopuses that were fed the semi-moist diet. Furthermore, the pelleted diet stimulated higher activity of acidic proteolytic enzymes, and chymotrypsin activities in the caecum as a physiological response to improve nutrient absorption and assimilation. Therefore, such a diet could be utilized as a starting point to design formulated diets for octopus.

Automated summary

The study found that compared to the semi-moist diet, the pelleted diet was more stable in water and had lower leaching. Both diets had similar effects on the growth, survival, feed efficiency and conversion rates of octopuses, but the semi-moist diet had higher protein and energy intake rates. The pelleted diet also stimulated higher digestive enzyme activity, promoting nutrient absorption and utilization.