Orange-Stripe Triggerfish

Balistapus undulatus

The orange-stripe triggerfish (Balistapus undulatus), also known as the undulate triggerfish, is a medium-sized triggerfish reaching up to 30 cm in length. It has a deep, compressed body with a striking coloration: dark green to olive-brown background covered with diagonal orange lines on the body and face, and orange or yellow markings around the mouth. The caudal peduncle features forward-pointing orange spines used in territorial disputes. Like all triggerfish, it possesses a locking dorsal spine that it erects when sheltering in crevices, making it nearly impossible to extract. This species is found throughout the Indo-Pacific on coral reefs, particularly in areas with mixed coral and rubble. It feeds on coral tips, sponges, tunicates, algae, and a variety of invertebrates, using its powerful jaws and teeth to crush hard-shelled prey. The orange-stripe triggerfish is notoriously territorial and aggressive, particularly during the breeding season when females guard egg nests and will charge at divers who venture too close.