Doubleband Surgeonfish

Acanthurus tennenti

Habitat & Distribution :  Indian-Pacific Ocean

Diet : Algae

Size: 25 -  50 cm

Lifespan: 10 - 20 years

Description

Doubleband Surgeonfish exhibits a variable body color—ranging from brownish-orange (beige) and yellowish-brown (olive-tan) to steel-gray. A dark line runs along the base of the dorsal fin, with a similar line at the base of the anal fin. Two dark streaks appear behind the eye, accompanied by a black, scalpel-like spine protruding from the base of the tail, which is surrounded by a large black patch with a bluish border.

Behavior

Doubleband Surgeonfish is highly territorial toward other surgeonfish that share similar body shapes or coloration. They view fellow algae-eaters as direct competitors that might usurp their food sources. These fish spend the majority of their daylight hours constantly swimming from one coral outcrop to another, grazing on algae.

Reproduction

The Doubleband Surgeonfish reproduces via external fertilization. The female approaches the surface of the coral reef and begins releasing eggs, while the male follows and releases sperm in response. Once the gametes meet and the eggs are fertilized, the resulting larvae drift in the water column for a period, passing through the planktonic stage. After approximately seven weeks, the larvae return to the coral reef habitat to settle.

Communication & Perception

During the mating season or instances of territorial rivalry (intraspecific competition), the Doubleband Surgeonfish can rapidly alter the intensity of its body coloration—shifting to lighter or darker shades—to signal dominance or attraction.

Predator

Snapper, grouper, and reef shark.