Yellowtail Fusilier

Overview

The yellowtail fusilier (Caesio cuning) is a schooling marine fish widely distributed across the Indo-West Pacific. Often found in coastal areas, this species is frequently observed swimming in midwater columns near rocky and coral reefs, where it relies on currents to bring in its primary food sources.

Distribution & habitat

This species is native to the Indian and Western Pacific Oceans, ranging from Sri Lanka and the Maldives in the west to Vanuatu in the east, and from southern Japan to northern Australia. It typically inhabits coastal environments, including lagoons and areas with rocky or coral substrates. While it is often found in clear reef waters, it is also known to frequent silty areas with lower visibility.

Appearance

This fusilier has a deep, laterally compressed, and fusiform body. Its coloration is distinctive, featuring a greyish-blue upper body that transitions to a white or pinkish abdomen. A prominent yellow patch covers the rear of the back, the caudal peduncle, and the entire tail fin. The pectoral, pelvic, and anal fins are generally white to pink, with a characteristic black spot located at the base of the pectoral fin.

Biology & behavior

Yellowtail fusiliers are diurnal, highly mobile, and social, typically forming large schools in midwater. They are non-territorial but can occasionally display aggression toward other species. As an oviparous species, they release numerous small, pelagic eggs into the open water to be dispersed by currents.

Feeding

Equipped with a small, protrusible mouth, this fish is a specialized planktivore. Its diet consists primarily of zooplankton, including copepods, cladocerans, salps, doliolids, pteropods, and the larvae of various reef organisms.