Sponge Cardinalfish

Phaeoptyx xenus

The Sponge Cardinalfish is a small reef-associated fish commonly found in the Western Central Atlantic, from southern Florida and the Bahamas to the northeastern Gulf of Mexico and Venezuela. It typically inhabits depths ranging from 5 to 20 meters, although it can be found as deep as 60 meters. This species is often seen in coral reefs and rocky bottoms, favoring cylindrical sponges such as Verongia fistularis, Callyspongia plicifera, and Callyspongia vaginalis. The Sponge Cardinalfish reaches a maximum length of 7.5 cm and is known for its mouthbrooding reproductive behavior. During courtship and spawning, distinct pairing occurs, with males carrying the fertilized eggs in their mouths until they hatch. This species is harmless to humans and is categorized as Least Concern by the IUCN. Divers encountering the Sponge Cardinalfish may observe its preference for hiding within sponges, making it somewhat cryptic.