Vibrio peaked in yellow tang larvae as brine shrimp joined their diet

Hatcheries raising sought-after reef fish such as the yellow tang struggle to get enough larvae through to the juvenile stage. A study published in PeerJ on September 21, 2026, looked at one part of that early stage: the microbes in the gut. Researchers at Hawaiʻi Pacific University and its Oceanic Institute followed a single cohort in a recirculating system from hatching to 76 days, sampling the larvae, their food and the rearing water at eight points.¹²

The gut community changed with each stage of development, and its biggest swings lined up with changes in food. Bacteria of the genus Vibrio made up 97.2% of the gut sequences at 36 days and 94.2% at 55 days. Both peaks came when enriched Artemia brine shrimp were added to the diet.¹

These are proportions from one cohort in one system. They show a timing pattern and do not establish a cause or any effect on the fish’s health. The authors say live foods may shape a young fish’s microbes and that the Vibrio species carried in feed need closer study.¹