Flower Cardinalfish

Ostorhinchus fleurieu, commonly referred to as the flower cardinalfish, gold cardinalfish, bullseye cardinalfish, or ringtail cardinalfish, is a species of cardinalfish endemic to a range of marine environments. These include the 🌊 Red Sea, 🌊 Persian Gulf, 🌊 Gulf of Oman, coastal regions surrounding East Africa, 🇸🇨 Seychelles, 🇮🇳 India, 🇱🇰 Sri Lanka, the Indo-Malayan region, and 🇭🇰 Hong Kong, extending southward to Ashmore Reef in Western Australia. It is notable as the type species for the genus Ostorhinchus. The specific epithet commemorates Charles Pierre Claret, comte de Fleurieu (1738-1810), a distinguished French explorer and hydrographer, and an acquaintance of Lacepède.

Characterized by its coppery hue, Ostorhinchus fleurieu features a distinctive broad blackish band at the base of its tail and can reach a length of up to 12.5 cm. Juvenile specimens display a spot rather than a bar at the tail base. Additionally, the species is marked by a narrow blue streak on the upper jaw and a broad blackish stripe extending from the snout to the eye. It is important to note the potential for confusion with Ostorhinchus aureus, which is differentiated by a narrower tail bar in its central region compared to the ends.

Adult Ostorhinchus fleurieu typically inhabit coral reef environments, forming small schools that consist of paired individuals. They are found at depths ranging from 7 to at least 73 meters. These fish predominantly occupy shallow coral reef areas where moderate currents are present and are often seen congregating in crevices within small to large schools.