Banggai Cardinalfish

Pterapogon kauderni

Habitat & Distribution :  Coral reef, endemic to the waters of Banggai Islands, Central Celebes

Diet : Zooplankton and small crustaceans

Size: Up to 8,6 cm

Lifespan: 2 - 5 years

Description

The Banggai cardinalfish has a silvery body with three black stripes across its eye, below its dorsal fin, and near its tail fin. Its second dorsal fin elongates with a black line and its tail fin is deeply forked with black stripes and white spots. The dorsal and ventral fins are completely black with white spots.

Behavior

The Banggai cardinalfish is endemic to the waters of Banggai islands, living in groups of up to 9 individuals in shallow waters, near seagrass beds or coral reefs. It is the only diurnal fish of its family, actively foraging for food during the day. When resting, it will shelter itself among the branches of the Acropora corals or other simialar invertebrates. As juveniles, they take shelter amongst anemone tentacles.

Reproduction

This fish has a unique courtship ritual. After picking out a potential mate, the female isolates him in her self-made spherical territory, where she will then initiate courtship behavior of "trembling" by his side. She will continue to tremble until the male opens its mouth to signal his readiness. 

Females only lay about 90 small eggs, which will be quickly fertilized and deposited into the male's mouth, where they will remain protected from predators until they're ready to hatch. This process is called mouthbrooding. 

Communication & Perception

Communicates visually through gestures and physical contact. Relies on vision, sounds and smells to forage and avoid threats.

Predator(s)

Lionfish, stonefish, ribbon eels, crocodile fish, and sea snakes 

Conservation Status: Endangered (IUCN Red List; 2025)