The Ruby Cardinalfish (Apogon coccineus) is a tropical marine species known for its association with reef environments, typically inhabiting depths ranging from 8 to 35 meters. The species reaches a maximum length of 6 cm. Notably, Apogon is derived from Greek, where 'a' signifies 'without' and 'pogon' means 'chin' or 'beard.'
Morphologically, the Ruby Cardinalfish is characterized by seven dorsal spines and nine dorsal soft rays, alongside two anal spines and eight anal soft rays. It exhibits a semi-transparent, reddish appearance with blackish scale edges dorsally.
Ecologically, it resides in sheltered reef flats, lagoons, and external reef regions, reaching depths of up to 17 meters or beyond. The fish is nocturnal, feeding on small benthic crustaceans, while remaining cryptic during daylight hours by hiding under rocks or within deep crevices.
Reproductive behavior includes mouthbrooding and distinct pairing observed during courtship and spawning. Geographically, the Ruby Cardinalfish is distributed across the Indo-Pacific, extending from the 🌊 Red Sea and East Africa to the Marquesan and Easter Islands, and as far north as southern 🇯🇵 Japan, and south to Lord Howe Island.
Why it's threatened
Threat classification from the IUCN Red List.
