blacktail butterflyfish

The body, laterally compressed and oval in shape, reaches a standard length of 110 mm (up to 12 cm total length). The coloration is characterized by an orange-yellow base with dark longitudinal lines, denser on the upper half, while the ventral region turns to pure orange.

The head features a black chin and two diagonal bands: a wide band crossing the eye and a finer one along the edge of the preoperculum. The dorsal fin, white, displays a black triangle bordered in yellow on its posterior margin.

The anal and caudal fins are black, the latter being rounded and adorned with a thin proximal yellow band followed by a distal transparent band. The pectoral and pelvic fins are yellow.

The blacktail butterflyfish is territorial and is usually observed solitarily or in pairs. Juveniles exhibit specific behavior by exclusively inhabiting coral heads until reaching sexual maturity.

This species closely depends on the structural complexity of the reef and the abundance of corals to maintain its feeding territories. Faced with massive bleaching or food loss, the animal may alter its strict territorial behavior to undertake food search excursions, demonstrating plasticity in response to environmental stress.

This fish is an obligate corallivore, feeding mainly on coral polyps, with a marked preference for the Acropora, Pocillopora, and Porites genera. Additionally, it consumes gastropod eggs and anemones. Its feeding rate and spatial distribution directly correlate with the available living coral cover.

The species is oviparous and forms distinct pairs for reproduction. Fertilization is external, and the pelagic eggs are released into the water column. Sexual maturity coincides with the moment when juveniles leave their coral heads to enter larger reef areas.