Size at Maturity for Yellow Tang ( Zebrasoma Flavescens ) from the Oahu, HI, Aquarium Fishery

While prior research has examined age, growth, and reproduction of yellow tang (Zebrasoma flavescens), size at maturity was only preliminarily assessed and is a very important biological metric to fully understand yellow tang biology and population status. We had a unique opportunity to sample from the Oahu, Hawaiʻi, aquarium fishery and across a size range from 55- to 110-mm total length (TL). We found a smaller than expected size at maturity for females (L50 = 63.4-mm TL (CI: 62.7 – 65.5-mm TL)) and males (L50 = 67.4-mm TL (CI: 66.4 – 70.3-mm TL)). Females as small as 65-mm TL had ovaries that contained hydrated oocytes, suggesting that spawning can occur at a size that was previously considered within the juvenile size range. However, very low gonad weights (< 0.26 g) limit any significant egg production from these small, young individuals. These results provide additional insight into the biology of Z. flavescens, but further research is needed to determine if size at maturity varies spatially and under different levels of fishing pressure.