Evaluación de la influencia de los ácidos húmicos y fúlvicos en la pigmentación de litopenaeus vannamei.

Abstract

This study aimed to evaluate the effect of humic acids (HA) and fulvic acids (FA) applied to the culture water on the pigmentation of white shrimp (Litopenaeus vannamei), a key trait for its commercial value. The experiment was conducted at the “Romero” shrimp farm in Arenillas, Ecuador, using a completely randomized design with three treatments (3 mg/L of HA combined with 2.5, 5, and 10 mg/L of FA) and a control, each with three replicates over seven days. Microalgae density (cells/ml), water quality parameters (ammonium, nitrites, salinity, temperature, dissolved oxygen, and pH), and shrimp pigmentation (both live and cooked) were monitored. Pigmentation was assessed through standardized photography, visual classification using the A1–A4 scale, and hexadecimal color codes. The results showed that treatment T2 (3 mg/L HA + 5 mg/L FA) led to the highest microalgae growth (50.39% increase) and significantly improved water quality. However, no visible changes in pigmentation were detected, as all shrimp remained within the A2 range at the beginning and end of the experiment, both live and cooked. It is concluded that under the evaluated conditions, humic and fulvic acids did not induce a perceptible pigmentation response. Future research should consider additional environmental variables such as background color, lighting, exposure time, or supplementation with pigmented microalgae to naturally and sustainably enhance shrimp coloration.