Yellow boxfish

The yellow boxfish (Ostracion cubicum) is a species of boxfish found in reefs throughout the Pacific Ocean and Indian Ocean as well as the southeastern Atlantic Ocean. Recorded occasionally since 2011 in the Levantine waters of the Mediterranean Sea which it likely entered via the Suez Canal, it is a species appreciated in the aquarium trade.

O. cubicum reaches a maximum length of 45 cm. As the name suggests, it is box-shaped. Boxfish are also known for their armored and rigid body which in most cases would inhibit locomotion. This disadvantage is offset by the boxfish's carapace shape which is much more advantageous for its adapted style of swimming, known as ostraciiform locomotion. When juvenile, it is bright yellow in color. As it ages, the brightness fades and very old specimens have blue-grey to black coloration with faded yellow.

While they are mainly known to reside in Indian coasts, earlier records show that this species has earlier reports in the Lakshadweep Islands, Andaman & Nicobar Islands as well as the Chennai coast

The yellow boxfish's diet consists mainly of marine algae, but it may also feed on worms, sponges, crustaceans, molluscs, and small fish.

When stressed or injured it releases the neurotoxin tetrodotoxin (TTX) from its skin, which may prove lethal to fish in surrounding waters. The bright yellow color and black spots are a form of warning coloration (aposematism) to any potential predators.

Yellow boxfish are solitary animals. Breeding occurs during the spring, in small groups that consist of 1 male and 2–4 females.

In 2006, Mercedes-Benz unveiled its Bionic concept car, which was inspired by the shape of the yellow boxfish. It was assumed that due to the extreme agility with which boxfish maneuver, that their shape was aerodynamic and self-stabilizing. However, analysis by scientists suggests that boxfish agility is instead due to the combination of an aerodynamically unstable body and the manner in which the fish use their fins for movement.