Blueline Angelfish

Chaetodontoplus septentrionalis

Also known as Bluestriped Angelfish, Blue Line Angelfish

SaltwaterFish

Blueline Angelfish (Chaetodontoplus septentrionalis) — Photo by and (C)2007 Derek Ramsey (Ram-Man) · CC BY-SA 2.5

Care at a glance

Temperature: 72–79°F (22–26°C)
pH: 8.1–8.4
Adult size: 8.7 in (22 cm)
Minimum tank: 185 gal (700 L)
Temperament: Mostly peaceful
Social behavior: Solitary
Tankmates: Tankmates with caution
Swim level: Middle
Difficulty: Medium
Breeding: Hard
Rarity: Rare
Reef safe: Not reef safe
Origin: Northwest Pacific, Malay Peninsula north to Taiwan and southern Japan
Family: Pomacanthidae

Overview

Provide about 700 litres with mature rockwork and water at 22 to 26 C, kept toward the cooler end where possible since this is a subtropical fish. Wild imports have a reputation for refusing food, so seek captive-bred stock, which takes pellets, mysis and nori readily. It picks at corals, clams and tubeworms, so treat it as a fish for rocky or fish-only displays.

In the wild

Blueline angelfish live on rocky coastal reefs of the northwest Pacific, from the Malay Peninsula north through Taiwan to southern Japan. They stay shallow, mostly between 5 and 15 meters, working over rock faces for sponges and tunicates. The species name septentrionalis means northern, since it ranges farther north than most angelfish.

Good to know

Chaetodontoplus septentrionalis grows to about 22 cm, with electric blue lines over a brownish body in adults. Juveniles look completely different, black with a single yellow bar behind the head, and only gain the lines with age. In southern Japan it naturally hybridizes with the black velvet angelfish, Chaetodontoplus melanosoma.

Did you know

Bali Aquarich worked out captive breeding for this species, and farmed bluelines have turned a once touchy import into a far more dependable aquarium fish.