Porcupine pufferfish (Diodon holocanthus) care guide

Group
Marine fish
Other names
Long-spine porcupinefish, Freckled porcupinefish, Balloonfish
Family
Diodontidae (porcupinefishes)
Origin
Circumtropical; muddy seabeds, estuaries, lagoons and coral and rocky reefs in tropical and subtropical seas.
Water
saltwater
Maximum size
50 cm
Temperature
24–27°C
pH
8.1–8.4
Hardness
Salinity SG 1.020–1.025
Minimum tank
700 litres
Care level
intermediate
Temperament
peaceful
Reef safe
no

Care

A large, endearing fish for a big fish-only system with open swimming space and caves for shelter. The minimum tank size given is an estimate from the adult size. Water figures given here are general marine aquarium guidance, not species-specific: 24–27 °C, pH 8.1–8.4 and a specific gravity of 1.020–1.025 (fish-only systems can run at the lower end). Puffers produce a lot of waste, so strong skimming and regular water changes matter. It is mainly active at night, though aquarium fish often learn to feed by day. Young and part-grown fish sometimes gather in groups. The tan body has faint darker spots, and long spines lie flat until the fish inflates. Avoid netting it out of the water, as it may gulp air. Toxins: porcupinefish are related to puffers and are generally regarded as carrying tetrodotoxin in their organs; they should never be eaten. Selling: our policies require the adult size and long-term tank needs to be stated clearly in the listing. Large fish must travel by a specialist live-animal courier (see the Livestock shipping guide). Sources: Wikipedia, List of marine aquarium fish species (en.wikipedia.org/wiki/Listofmarineaquariumfishspecies); Wikipedia (en.wikipedia.org/wiki/Diodonholocanthus). Checked October 2026.

Diet

An omnivore that crushes hard-shelled prey such as molluscs, sea urchins, crabs, hermit crabs and snails with its fused beak. In the aquarium give whole shellfish, prawns, crab, krill and mussel; hard foods help keep the beak worn down.

Breeding

In the wild it spawns at the surface at dawn or dusk, either in pairs or as a group of males with one female. Juveniles live in open water until they are at least 7 cm long. Not bred in home aquaria.

Compatibility and tank mates

Not reef safe: it eats crustaceans, snails and other invertebrates. Generally peaceful with fish too large to swallow, but avoid fin-nippers that may pick at it.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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