Giant Damselfish (Adult)

Family: Damselfishes (Pomacentridae)
Size: Up to 31 cm (12 in) | Common: 20 cm
Depth: 1 – 15m (3 – 50ft)

Distribution: Eastern Tropical Pacific (Baja California to Colombia and the Galapagos Islands).

Identification: A large, imposing damselfish that acts as the fierce guardian of the shallow reefs.

• Robust & Dark: Adults possess a deep, slate-blue to almost black, heavy-set body with prominent, pale whitish lips.
• Glowing Eyes: Even as they lose their brilliant juvenile spots and transition into their dark adult phase, they retain a striking, bright neon-blue ring around their eyes.
• Sweeping Fins: They feature a deeply forked tail and long, trailing filaments on their dorsal and anal fins, giving them a sweeping profile in the water.

Behavior: Highly territorial "farmers" of the reef.

• Algae Gardens: They cultivate and aggressively defend their own private patches of red and green algae on the rocky substrate.
• Fearless Defenders: They are completely fearless. If a diver or a much larger fish hovers too close to their territory along the Chocó coast, they will boldly charge, grunt, and even nip to chase the intruder away.