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Email the author (Login required) Total digestibility coefficients and protein content in experimental food for juvenile of San Pedro, Oplegnathus insignis (Kner, 1867) (Perciformes, Oplegnathidae)
DOI: https://doi.org/10.3856/vol43-issue2-fulltext-5
Abstract
Fish feeds are formulated with different ingredients, where fishmeal is the main source of protein. However, this input has a high cost, which leads to the need to evaluate new sources of protein and test them on marine species. Oplegnathus insignis (San Pedro, Pacific beakfish) is an omnivorous fish during its intertidal life stage switching to carnivore when it lives in subtidal habitats. This species has been reared experimentally, being necessary to incorporate formulated diets. To this end, this study reports the experiments in food and nutrition in juvenile O. insignis fed with formulated diets with different protein sources. The experiments were performed with hatchery-produced juvenile fish. Four foods, one based on fishmeal (reference) and three modified, replacing 30% of fish meal by other protein sources derived from soybean meal, mollusc meal and quinoa meal. We experimented with 180 ind. of 295.6 g and 450 days post-hatching, distributed in 12 rectangular tanks of 1.6 m3. The feed was offered to satiety. Proximal analysis of experimental foods was performed in the feeds and faeces collected. Digestibility coefficients and total proteins were determined. The food with higher protein content was the flour containing molluscs meal. The higher total digestibility coefficient was determined in those foods made with fishmeal (68.0%) and molluscs meal (67.1%), while in those foods containing vegetable meals, total digestibility values were 62.7% for soybean meal and 64.1% for quinoa meal respectively. These results indicate that it is feasible to replace up to 30% fishmeal by vegetable flours.
