Review scope

This summary is based on the published abstract. We have not appraised the full methods, tables or supplementary material. Details absent from the abstract remain unverified.

Question and design

120 juvenile goldfish in 24 aquariums, studied for 56 days. Astaxanthin-supplemented food and biofloc rearing, tested factorially. Comparator: Unsupplemented food and clear-water rearing.

What was measured?

Growth, survival, feed conversion, colour and skin carotenoids.

Main findings

Both supplementation and biofloc increased redness, yellowness and skin carotenoids. No effects on weight gain, survival or feed conversion were reported; no system-by-diet interaction was detected.

Study strengths

Factorial comparison separates dietary and rearing-system effects.

Limitations

Juvenile aquarium production conditions. Colour is not a general-health endpoint; one amount and duration were tested.

Researchers’ conclusion

The authors supported biofloc for pigmentation, with additional dietary carotenoids intensifying colour.

Evidence.pet interpretation

The study supports a defined pigmentation result, not a claim that a brighter fish is healthier.

Funding and conflicts

Not verified from the abstract; full declarations have not been reviewed.

Source and review date

Biofloc technology (BFT) improves skin pigmentation of goldfish (Carassius auratus). Aquaculture. 2020;522:735132. DOI: 10.1016/j.aquaculture.2020.735132.

Read the primary source · DOI record

STU-045. Reviewed 25 September 2026. Next review 25 December 2026.