Đánh giá hiệu quả của astaxanthin từ copepoda trong việc tăng cường màu sắc ở cá khoang cổ nemo (<i>Amphiprion ocellaris</i>)

Abstract

In ornamental fish farming, colouration plays a crucial role in determining the value and market acceptance of the fish. However, captive fish often have inferior colouration compared to their wild counterparts, posing a significant challenge. To address this issue, we conducted a study using astaxanthin extracted from Copepoda, Pseudodiaptomus annandalei, as a dietary supplement to enhance the colouration of captive clownfish, Amphiprion ocellaris. We tested five levels of astaxanthin supplementation, ranging from 50 - 450 mg/kg of feed, along with a control group. The fish were raised in glass tanks with 60 litres per tank, housing 15 individuals each. Each treatment was replicated three times over 75 days. The results demonstrated that the evaluated color improvement indices, such as a^* (green-red), b^* (blue-yellow), H^o_ab (hue angle), C^o_ab (color saturation), ΔE (overall color difference), and the accumulation of carotenoids (in the skin and muscle), showed better outcomes with higher levels of supplemented astaxanthin (P < 0.05). The treatment with 450 mg/kg of astaxanthin exhibited the highest levels of redness and carotenoid accumulation on the fish skin, representing a respective increase of 111% and 270% compared to the control group. This study provides an effective solution for enhancing the coloration of clownfish species, thereby contributing to the improvement of breeding stock quality that meets market demands.

Keywords: Astaxanthin, accumulated carotenoid content, colouration, Copepoda, false clownfish.