Apogon quadrilineatus, commonly known as the four-lined cardinalfish, is a small, vibrant species belonging to the Apogonidae family, thriving in the warm, tropical waters of the Indo-Pacific region. Renowned for its striking pattern and nocturnal habits, this fish is characterized by a sleek, elongated body with a deep red to orange hue, adorned with four distinct horizontal black lines that run the length of its flanks, creating a bold contrast against its vivid coloration.