White-Banded Triplefin

Enneapterygius etheostoma

The White-banded triplefin is a small reef fish found in the northwestern Pacific Ocean, specifically around Japan, China, Korea, Hong Kong, Taiwan, and Vietnam. It inhabits rocky shores and is typically observed at depths ranging from 0 to 21 meters. Male White-banded triplefins can grow up to 5.9 centimeters in length, while females are characterized by their white bodies with 4-5 brownish-red H-bars. Males, on the other hand, are black with two distinctive white bars located below the junction of the second and third dorsal fins. The caudal fin features alternating white and reddish-brown marks, making it distinguishable from other species. These fish primarily feed on benthic algae, which they graze from the rocky substrates they inhabit. The species reproduces by laying eggs that are hemispherical and equipped with sticky threads, allowing them to anchor securely in algae at nesting sites. The larvae are planktonic and are mostly found in shallow, nearshore waters. Divers encountering the White-banded triplefin may find them perching on rocks or moving slowly along the substrate. They are harmless to humans and are not of interest to fisheries. The species is currently listed as Least Concern on the IUCN Red List.