The Cardinalfish (Apogon imberbis) is a marine (saltwater) fish in the Apogonidae family. It is also known as the Mediterranean Cardinalfish or the King of the Mullets.

The Cardinalfish has a compressed body with a large head and a large mouth. Its lower jaw protrudes over its upper jaw. It is reddish-pink with a round black eye. It has two or three dark spots on the base of its caudal fin. 

It grows to 10-12 centimetres (4-5 inches) long.

The Cardinalfish is common in the Mediterranean Sea. It prefers warm temperate and tropical eastern Atlantic coastal waters. It is not found in the Black Sea. 

It likes rocky coral reefs. 

It is nocturnal, active mostly at night. During the day, it rests in cavities or caves individually or in small groups. 

It feeds on small fish, plankton, and invertebrates, such as worms. 

It is a mouthbrooding fish. After the female lays eggs, the male puts them in his mouth to prevent other fish from eating them. As the eggs hatch into small fish, called fry, the male continues to protect them in his mouth. 

Photographer: Martina Nicolls

Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM