Figure-8 Puffer

Dichotomyctere ocellatus

Also known as: Figure 8 puffer, Eyespot puffer, Figure-eight pufferfish

Water Parameters

• Temperature: 22–27°C
• pH: 7–8
• Hardness (GH): 89–268 ppm (5–15 dGH)

Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.

Care Summary

A small, intelligent pufferfish patterned in gold and black figure-eight loops, the figure-8 is one of the most rewarding of the small puffers, but a specialist rather than a community fish. The key point is water: it can be kept in fresh water, but it does best, and tends to live longest, in slightly salty, low-end brackish water around a specific gravity of 1.005, and it is a messy, nippy fish either way, so it is not a community species. Reaching around 8cm, it is a strict carnivore whose teeth grow continuously and must be worn down with hard-shelled foods, so a steady supply of small snails is part of its care, not optional. It is best kept one to a tank, in pristine, stable conditions. Given the right water, a snail-based diet, and a tank of its own, it is a long-lived (often ten years or more) and endearing character. Not a beginner's community fish, but a superb project for a dedicated keeper.

Tankmates

Best kept entirely alone. The figure-8 puffer is nippy and territorial, inclined to bite the fins of slow or long-finned tankmates, and it hunts and eats snails and shrimp, which are food rather than companions. It is often kept in low-end brackish water (a specific gravity around 1.005), which few community fish share, though it can also be kept in fresh water. At most, some keepers risk fast, robust, salt-tolerant dither such as mollies, but a species-only tank is strongly preferred, and only one puffer should be kept per tank.

Compatible with

• Molly

Avoid keeping with

• Cherry Shrimp
• Nerite Snail
• Betta
• Guppy
• Community Fish

Common Problems

• missing the low-end salt that tends to extend its lifespan
• overgrown teeth when not fed enough hard-shelled snails
• nipping the fins of tankmates
• sensitivity to ammonia and nitrite
• being added to a community tank, where it does not belong

Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-10-13