Lined Bristletooth

The striated surgeonfish, scientifically known as Ctenochaetus striatus, is a species of marine fish within the family Acanthuridae, which includes well-known groups like tangs and unicornfishes. This species, first described in 1825 by French naturalists in 🇬🇺 Guam, is widely distributed across the Indo-Pacific region.

Ctenochaetus striatus has a distinctive appearance characterized by a greenish-brown body adorned with slender blue lines along its sides and numerous orange spots on its head. These blue lines extend onto its dorsal and anal fins. The fish features a dorsal fin with 8 spines and 27-31 soft rays, and an anal fin with 3 spines and 24-28 soft rays. It can reach up to 26 cm (10 inches) in length.

This species is typically found in environments such as reef flats, lagoons, and seaward reefs, thriving over coral, rocky surfaces, and rubble at depths from 0 to 60 meters (0 to 197 feet). It is commonly seen alone or in groups, sometimes forming large schools with other species.

Striated surgeonfish have a diet that mainly consists of algae, diatoms, and small marine creatures, playing an essential role in their ecosystem. Notably, their presence is linked to the phenomenon of Ciguatera fish poisoning. When Pacific cyclones decrease, the population of herbivorous fish like the striated surgeonfish often increases, affecting ciguatera's occurrence in humans.

Reproduction in Ctenochaetus striatus is intriguing, generally occurring during the full moon. At this time, these fish form large groups, briefly changing color before certain individuals ascend to the surface to spawn. What's particularly interesting about their larvae is their attraction to noisy environments—a behavior that sets them apart from other coral fish larvae.

Overall, the striated surgeonfish is an integral part of the marine biodiversity across its range, contributing to both the health of coral reefs and the challenges of ciguatera in affected regions.