TankBud

Spotted boxfish

Ostracion meleagris

Also known as Whitespotted boxfish, Blue boxfish, Pacific boxfish, Spotted trunkfish

SaltwaterFish

Spotted boxfish (Ostracion meleagris)
Diego Delso · CC BY-SA 4.0

Care at a glance

Temperature
75–81°F
24–27°C
pH
8.0–8.4
Adult size
7.9 in
20 cm
Minimum tank
90 gal
340 L
Temperament
Mostly peaceful
Social behavior
Solitary
Own kind
One male per tank
Tankmates
With caution
Swim level
Middle
Diet
Omnivore
Difficulty
Difficult
Breeding
No record
Rarity
Common
Reef safe
Reef safe with caution
Family
Ostraciidae
Origin
Native to the Indo-Pacific, living on coral reefs and lagoon slopes where it drifts slowly over the bottom.

Overview

The spotted boxfish is a slow, box-shaped reef fish for a large, peaceful saltwater tank. It is a fish for experienced keepers.

Did you know

A badly stressed spotted boxfish can leak a skin toxin called ostracitoxin into the water. The toxin can be potent enough to kill every fish in the tank, including the boxfish itself.

Caring for the spotted boxfish

Keep a spotted boxfish in a peaceful tank of at least 90 gal (340 L), with rockwork. It leaves corals alone but may pick at small invertebrates, so add it to a reef tank only with caution.

Hold the water at 75 to 81°F (24 to 27°C) and a pH of 8.0 to 8.4. Feed a varied diet of meaty foods, marine algae and some hard-shelled items several times a week.

The spotted boxfish is a slow, clumsy swimmer that is easily nipped or outcompeted, so avoid aggressive or fast fish. Choose calm tank mates with caution. Its toxin is the real risk, so never house it with fish that harass it.

It is a solitary fish, and a tank should hold no more than one male. Males are dark blue on the sides, with a black back covered in white spots. Females and juveniles are black all over with white dots.

Good to know

Ostracion meleagris is a member of the family Ostraciidae. It is also known as the whitespotted, blue or Pacific boxfish, or as the spotted trunkfish. Its body is encased in a solid carapace of fused hexagonal plates, leaving only the fins, mouth and tail free to move. It swims by whirring its fins while the body stays stiff. Males and females are so differently colored that they were once mistaken for separate species.

In the wild

The spotted boxfish is native to the Indo-Pacific, where it lives on coral reefs and lagoon slopes. It drifts slowly over the bottom, hovering and humming over the reef as it looks for small prey.

Common questions

What size tank does a spotted boxfish need?

A spotted boxfish needs at least 90 gal (340 L). It spends most of its time in the middle.

What temperature and pH does a spotted boxfish need?

A spotted boxfish is comfortable at 75–81°F (24–27°C) with a pH of 8.0–8.4.

What does a spotted boxfish eat?

A spotted boxfish eats a varied diet of meaty foods, marine algae and some hard-shelled items. Feed it several times a week.

How big does a spotted boxfish get?

An adult spotted boxfish reaches about 7.9 in (20 cm).

How can you tell a male spotted boxfish from a female?

Males are dark blue on the sides, with a black back covered in white spots. Females are black all over with white dots, like the juveniles.

Related species