Lunar Fusilier

The lunar fusilier (Caesio lunaris), also referred to as the blue fusilier or moon fusilier, is a marine ray-finned fish species within the Caesionidae family. This species is prevalent across the tropical waters of the Indo-West Pacific region.

This species was first formally documented in 1830 by the French zoologist Georges Cuvier, with New Ireland specified as the type locality. The lunar fusilier is classified under the subgenus Odontonectes. The species name "lunaris" translates to "of the moon," attributed to Christian Gottfried Ehrenberg, the collector of the type. Cuvier presumed that Ehrenberg chose this name due to the crescent-shaped row of scales on the fish's neck.

The lunar fusilier exhibits a moderately deep, fusiform, and laterally compressed body. Its dentition includes small teeth located in the jaws, vomer, and palatines. The dorsal fin is equipped with 10 spines and 13–15, typically 14, soft rays, while the anal fin possesses 3 spines and 10, rarely 11, soft rays. Scales are present on both the dorsal and anal fins. The pectoral fins contain 18–21, commonly 19 or 20, rays. This species can reach a maximum total length of 40 cm (16 in). The body manifests a bluish coloration, shifting to a paler shade on the ventral side. In adults, the caudal fin lobes are blue with a black tip on each lobe. The pectoral fins display a black axil and upper base, whereas the remainder of the pectoral fins, pelvic fins, and anal fins appear white to pale blue, contrasted with the bluish dorsal fin. Notably, juveniles often exhibit a yellow caudal fin and yellow markings on parts of the caudal peduncle.

The lunar fusilier is widely distributed throughout the Indo-West Pacific. Its habitat extends along the eastern coast of Africa from the 🌊 Red Sea to Sodwana Bay, KwaZulu-Natal (🇿🇦 South Africa), 🇿🇦 South Africa, and eastward across the 🌊 Indian Ocean, including regions such as the 🌊 Persian Gulf. In the Pacific, its range spans to the 🇲🇭 Marshall Islands and 🇫🇯 Fiji, reaching north to southern 🇯🇵 Japan and south to northundefined and 🇳🇨 New Caledonia (🇫🇷 Overseas France). The species inhabits depths of up to 60 m (200 ft) in coastal waters, predominantly near coral reefs, favoring seaward slopes and lagoons.

Lunar fusiliers typically form large schools in midwater along the upper edges of steep slopes and around patch reefs. They are known to engage in mixed-species schooling with other fusiliers, primarily feeding on zooplankton. Adults forage in deep, clear waters away from reefs during daytime and retreat to reef shelters at night, while juveniles remain reef-associated. Juveniles frequently associate with other juvenile fusiliers, notably Caesio cuning. The lunar fusilier is an oviparous species, producing numerous small pelagic eggs.

Fishing activities target the lunar fusilier across its distribution range, utilizing methods such as drive-in nets, gillnets, seine nets, and fish traps. These catches are marketed as fresh fish. Despite being susceptible to overfishing and having shown declines in certain areas, the species remains abundant in many parts of its range.