Threadfin butterflyfish
Chaetodon auriga
Also known as Auriga Butterflyfish, Cross-stripe Butterfly
SaltwaterFish
Care at a glance
- Temperature
- 75–81°F
- 24–27°C
- pH
- 8.1–8.4
- Adult size
- 9.1 in
- 23 cm
- Minimum tank
- 79 gal
- 300 L
- Temperament
- Mostly peaceful
- Social behavior
- Solitary
- Swim level
- Middle
- Difficulty
- Medium
- Breeding
- No record
- Rarity
- Common
- Reef safe
- Not reef safe
- Family
- Chaetodontidae
- Origin
- Indo-Pacific and Red Sea, from East Africa to the Hawaiian Islands, north to southern Japan
Overview
One of the hardier, easier-to-feed butterflyfish, which makes it a common choice, but it is a committed omnivore that samples corals and inverts. Mostly peaceful toward other fish though it can squabble with other butterflies, so keep one per tank. It readily accepts frozen and prepared foods once settled.
In the wild
Threadfins range widely across the Indo-Pacific and Red Sea on coral-rich reefs, lagoons, and reef flats, from shallows down to about 35 metres. They are generalist foragers that pick at coral polyps, worms, algae, and small invertebrates. In captivity they need a large tank with live rock to graze on and plenty of open swimming room.
Good to know
Chaetodon auriga is one of the most widespread and hardy butterflyfish in family Chaetodontidae. The common name refers to the trailing filament (thread) extending from the rear of the dorsal fin in most populations. It bears a black eyespot on the dorsal fin. Adults reach around 23 cm, making it one of the larger Chaetodon species.
Did you know
Because it eats a broad range of foods and adapts well, C. auriga is often recommended as a first butterflyfish for fish-only systems, unlike most of its coral-obligate relatives that starve in captivity.
Weekly picks
Tank mates
Threadfin butterflyfish is a mostly peaceful, solitary species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Gold-specs jawfish
Opistognathus randalli
Saltwater3.9 in (10 cm) · 30 gal (115 L)73–81°F (23–27°C)
Skunk cleaner shrimp
Lysmata amboinensis
Saltwater2.4 in (6 cm) · 20 gal (75 L)73–81°F (23–27°C)
Fighting conch
Strombus alatus
Saltwater3.1 in (8 cm) · 20 gal (75 L)75–81°F (24–27°C)
Bellus angelfish
Genicanthus bellus
Saltwater7.1 in (18 cm) · 85 gal (320 L)72–79°F (22–26°C)
Blackline fang blenny
Meiacanthus nigrolineatus
Saltwater3.5 in (9 cm) · 20 gal (75 L)75–81°F (24–27°C)
Ring cowrie
Monetaria annulus
Saltwater1.2 in (3 cm) · 20 gal (75 L)75–81°F (24–27°C)
Common questions
What size tank does a Threadfin butterflyfish need?
A Threadfin butterflyfish needs at least 79 gal (300 L). It spends most of its time in the middle.
What temperature and pH does a Threadfin butterflyfish need?
A Threadfin butterflyfish is comfortable at 75–81°F (24–27°C) with a pH of 8.1–8.4.
How big does a Threadfin butterflyfish get?
An adult Threadfin butterflyfish reaches about 9.1 in (23 cm).
Related species
7.9 in (20 cm)106 gal (400 L)75–81°F (24–27°C)Raccoon butterflyfish
Chaetodon lunula
7.9 in (20 cm) · 106 gal (400 L)
7.1 in (18 cm)90 gal (340 L)73–81°F (23–27°C)Collare butterflyfish
Chaetodon collare
7.1 in (18 cm) · 90 gal (340 L)
9.1 in (23 cm)151 gal (570 L)75–82°F (24–28°C)Golden butterflyfish
Chaetodon semilarvatus
9.1 in (23 cm) · 151 gal (570 L)
5.9 in (15 cm)79 gal (300 L)75–81°F (24–27°C)Klein's butterflyfish
Chaetodon kleinii
5.9 in (15 cm) · 79 gal (300 L)
5.5 in (14 cm)75 gal (285 L)73–81°F (23–27°C)Pearlscale butterflyfish
Chaetodon xanthurus
5.5 in (14 cm) · 75 gal (285 L)
5.1 in (13 cm)75 gal (285 L)72–79°F (22–26°C)Milletseed butterflyfish
Chaetodon miliaris
5.1 in (13 cm) · 75 gal (285 L)
