TankBud

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
With caution
Swim level
Middle
Diet
Omnivore
Difficulty
Medium
Breeding
Hard
Rarity
Rare
Reef safe
Not reef safe
Family
Pomacanthidae
Origin
Northwest Pacific, Malay Peninsula north to Taiwan and southern Japan

Overview

The blueline angelfish is a mid-water angel for a rocky saltwater display without corals. It is a moderate challenge to keep.

Did you know

The blueline angelfish was a touchy import until Bali Aquarich worked out captive breeding for the species. Farmed bluelines are far more dependable aquarium fish.

Caring for the blueline angelfish

Give a blueline angelfish at least 185 gal (700 L), with mature rockwork. Keep the water at 72 to 79°F (22 to 26°C) with a pH of 8.1 to 8.4. It is a subtropical fish, so hold the temperature toward the cooler end where possible.

Wild imports have a reputation for refusing food, so seek out captive-bred stock. Captive-bred fish take pellets, mysis and nori readily.

The blueline angelfish is mostly peaceful, but choose its tank mates with caution. It picks at corals, clams and tubeworms, so it is not reef safe. Keep it in a rocky or fish-only display. Breeding it is hard.

Good to know

The blueline angelfish belongs to the family Pomacanthidae, and it is also called the bluestriped angelfish. Adults have electric blue lines over a brownish body. Juveniles look completely different, black with a single yellow bar behind the head, and gain the lines only with age. In southern Japan it naturally hybridizes with the black velvet angelfish, Chaetodontoplus melanosoma. Its species name, septentrionalis, means northern, since it ranges farther north than most angelfish.

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.

Common questions

What size tank does a blueline angelfish need?

A blueline angelfish needs at least 185 gal (700 L). It spends most of its time in the middle.

What temperature and pH does a blueline angelfish need?

A blueline angelfish is comfortable at 72–79°F (22–26°C) with a pH of 8.1–8.4.

What does a blueline angelfish eat?

A captive-bred blueline angelfish takes pellets, mysis and nori readily. Wild imports have a reputation for refusing food.

How big does a blueline angelfish get?

An adult blueline angelfish reaches about 8.7 in (22 cm).

Related species