Spot-fin Porcupinefish (Diodon hystrix) Care Guide
Diodon hystrix is a circumtropical porcupinefish reaching about 91 cm. It feeds on hard-shelled invertebrates and contains tetrodotoxin.
Overview
Diodon hystrix, the spot-fin porcupinefish, is a large member of the family Diodontidae. According to FishBase it reaches up to 91 cm total length, with a common length around 40 cm. The body is pale and covered with dark spots and spines that erect when the fish inflates. It is one of the largest porcupinefishes.
Taxonomy
- Family: Diodontidae
- Genus: Diodon
- Scientific name: Diodon hystrix Linnaeus, 1758
Habitat
FishBase reports a circumtropical distribution, including the eastern Pacific, western Atlantic and Indo-Pacific. Adults occur on lagoon and seaward reefs at depths from about 2 to 50 m, sheltering in caves and holes during the day. Juveniles are pelagic until they reach roughly 20 cm, after which they become benthic.
Tank requirements
Given its adult size, this species is suited to very large public-aquarium systems rather than home tanks. Parameters below follow the verified knowledge-base record.
- Minimum tank volume: 2500 L (660 gal)
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- GH: 8-12 °dGH
- Lifespan: 8-20 years (FishBase notes 10 years recorded in captivity)
Diet
Diodon hystrix is a carnivore. FishBase and Wikipedia describe it feeding on hard-shelled invertebrates such as sea urchins, gastropods, clams, hermit crabs and other crustaceans. Its fused beak-like teeth crush these prey.
Compatibility
The species is solitary and primarily nocturnal, with peak activity around sunset and sunrise. It is unsafe with ornamental shrimp, snails, crabs, corals and small fish, which it may eat. The verified record pairs it only with large, robust tankmates such as triggers and larger angelfish.
Defense and toxicity
When threatened, the fish ingests water to inflate its body and erect its spines, appearing much larger. Wikipedia notes that tetrodotoxin is concentrated in the liver, skin, gonads and viscera, and the species is poisonous to eat.
Conservation status
IUCN Red List: Least Concern (assessed 2011). FishBase rates its fishing vulnerability as low.