Avaliação nutricional de Artemia sp. alimentada com diferentes espécies de microalgas

Abstract

A very important characteristic of Artemia is that it is a non-selective filter feeder, in which it is capable of using and ingesting organisms that are smaller than its mouth. Consequently, the nutritional enrichment of Artemia meta-nauplius, essentially by microalgae, aims to offer specific nutrients, such as proteins, amino acids, polyunsaturated fatty acids, among others, to meet the nutritional requirements of post-larvae of aquatic organisms. The objective of the present work was to evaluate the protein and lipid content of the microcrustacean Artemia sp. fed with the microalgae species Arthrospira platensis, Chlorella vulgaris and Nannochloropsis oculata. An experimental design of five treatments with three replications each was used, in 60 L aquariums, with a useful volume of 25 L, adopting the following configuration: 1) Nauplius of Artemia sp., after hatching (control), 2) Meta- nauplius of Artemia sp., after 48 hours of hatching, 3) Artemia sp. fed on Arthrospira platensis, in the meta-nauplius stage, 4) Artemia sp. fed with Chlorella vulgaris, in the meta-nauplius phase and 5) Artemia sp. fed with Nannochloropsis oculata, in the meta-nauplius phase. The protein content of meta-nauplii and microalgae was determined using the Kjeldahl method. To analyze the total lipid content, the modified Soxhlet method was used. Of the three diets tested, the one that demonstrated the highest amount of protein absorbed by Artemia sp. it was the microalgae Chlorella vulgaris that presented 59.0% of extracted protein, followed by Nannochloropsis oculata with 58.8% and finally Arthrospira platensis with 52.8%. It is notable to note that the values were reduced when compared to meta-nauplii 48 hours after hatching without microalgae feeding, which presented extracted protein values of 60.2%. However, the percentages of lipids found were 5.8% for N.oculata, 4.9% for C. vulgaris and 3.1% for A. platensis. Given the values acquired, it was observed that the meta-nauplius without being enriched with microalgae contained a value of 17.4% lipid. Therefore, the present study demonstrated that non-enriched nauplii and meta-nauplii of Artemia sp. They have excellent protein and lipid values for feeding fish and shrimp larvae. However, bioencapsulation with microalgae demonstrated that Chlorella vulgaris had a higher level of protein absorbed by meta-nauplii, while Nannochloropsis oculata had a higher amount of lipids.