Scrawled Filefish

Overview

The Scrawled Filefish (Aluterus scriptus) is a distinctive, circumtropical marine fish known for its remarkable ability to change color and pattern to blend into its surroundings. Often found in tropical and subtropical waters, this species is recognized by its elongated, highly compressed body and unique, script-like blue markings.

Distribution & habitat

This species has a worldwide distribution across tropical and subtropical seas, including the Atlantic, Indian, and Pacific Oceans. While adults are typically associated with lagoons, coral reefs, and rocky areas, juveniles are often pelagic, frequently drifting in the open ocean among floating seaweed or debris.

Appearance

Aluterus scriptus features an elongated, oval-shaped body that is strongly compressed laterally. Its base color ranges from olive-brown to grey, adorned with irregular blue lines and scattered black spots. The fish has a small, upturned mouth at the end of a concave snout and a long, rounded caudal fin. Its skin has a rough, sandpaper-like texture due to tiny scales. A notable defensive feature is its long, erectile first dorsal spine, which can be locked in place by a smaller second spine to wedge the fish into reef crevices.

Biology & behavior

These fish are generally solitary and diurnal, remaining active during the day and resting on the reef at night. They are masters of camouflage, capable of rapidly shifting their colors to match substrates like sand or coral. When threatened, they may swim with their heads facing downward to mimic floating debris or wedge themselves into tight spaces using their dorsal spines.

Feeding

As an omnivore, the Scrawled Filefish has a varied diet that includes algae, seagrass, hydrozoans, gorgonians, colonial anemones, and tunicates.