Scribbled leatherjackets can be found in the lagoons and reefs of subtropical seas all over the world. Even though some individuals have been spotted at depths of over 120 meters, these fish usually dwell at shallower depths of around 20 meters.
Juveniles are pretty vulnerable to predators and have developed several hiding tactics. They often swim under floating objects, hiding among seaweed that is attached to the debris. Even when they grow bigger and leave the comfort and security of their hideout, they are masters of disguise. To avoid detection, they swim in a vertical position, trying as hard as they can to look and act like part of drifting vegetation.
Once they reach maturity, Scribbled leatherjackets develop additional defence mechanisms. One of their most exciting skills is their ability to camouflage. They can change the colour of their body to quickly match their background, similar to octopuses. If their disguise fails them, they can turn to a secret weapon. A spine on their head quickly turns into a dangerous underwater spear, and several other smaller spines on their body help them wedge securely into a crevice on the seabed. This technique not only keeps them safe from predators, but also helps them rest peacefully during the night.
Scrawled filefish, as they are also sometimes known, feed on algae, seagrass, hydrozoans, gorgonians, colonial anemones and tunicates.
Even though they prefer to swim solo, once they decide it is time to produce offspring, the scrawled filefish group into love triangles, or sometimes even pentagons consisting of one male and two to five females. Taking care of fertilized eggs and hatchlings is not usual in the fish world, but the scrawled filefish are dedicated parents and care for their young.
Written by Lena Ilic, B.Sc., Marine Biologist
Photos by Janez Kranjc