Pao Baileyi Pufferfish Care Sheet

Updated: Oct 25, 2020

This care sheet is written with the aim of providing the optimal care for this species of fish.

Pufferfish Enthusiasts Worldwide endeavours to inspire and promote the highest standards of care - not basic or minimum care - using the best evidence available at the time

Photo credit: Ryan Bullock
Pao baileyi

The baileyi is a species of freshwater pufferfish belonging to the Pao genus.

The P.baileyi previously belonged to the Monotrete and then the Tetraodon genera, until being reassigned in 2013 to Pao.

The species was discovered in 1985 and the specific name honours Professor Dr. Reeve M. Bailey, Professor of Biological Sciences and Curator of Fishes in the Museum of Zoology.

The cirri (epidermal outgrowths) that resemble hairs on the P.baileyi have earned it the common name of Hairy Puffer.

In the wild

The P.baileyi populations in the wild are still healthy in suitable habitats and it is considered 'Least Concern' by the International Union for Conservation of Nature (IUCN).
Mekong River, Thailand-Laos Border

P.baileyi is only found in the Mekong basin in Thailand and Laos.

It has been observed to nestle itself tightly within the crevices of the rock found in the fast flowing, highly oxygenated waters of the Mekong mainstream and its larger tributaries.

The P.baileyi populations in the wild are still healthy in suitable habitats and it is considered 'Least Concern' by the International Union for Conservation of Nature (IUCN).

The P.baileyi disguises itself as a rock, sitting motionless with only the cirri flowing with the current, imitating algae. It remains there, or wallowed in the substrate, ready to launch a surprise attack on any prey items that come within striking distance. It feeds on smaller species of fish, freshwater crustaceans and benthic animals such as worms.

In the aquarium

The P.baileyi is a popular choice for ‘oddball’ enthusiasts and imports of wild-caught specimens are quite common.

This pufferfish requires highly oxygenated water with a medium to strong flow, but not overpowering.

A good strength of flow can be achieved with spray bars from a canister filter, angled towards the top of the water.

Powerheads with narrow gaps in the grill can also be used to create additional flow. We would advise that cages or guards (such as anemone guards) are used on powerheads to prevent entrapment/injury.

This species prefers a scape which includes an abundance of spaces in which it can hide, but the tank must also provided lots of areas of uncovered substrate to allow for wallowing (read substrate).

Water-logged driftwood and smooth boulders/rocks can be incorporated into the scape of the aquarium. Hardy epiphytes, such as Anubias and Java fern varieties, can be attached to the hardscape for decorative purposes and to provide additional areas of harbourage, but plants that need to be planted into the substrate should be avoided because the P.baileyi will disturb the roots.


The P.baileyi is an ambush predator and will spend most of its time lurking in-between the aquarium decor and wallowing in the substrate. This is how this species naturally hunts, awaiting any potential prey to come within striking distance. It is important that the Baileyi puffer is provided with a very soft, sand substrate for wallowing. A soft sand substrate should be considered an essential and not an optional extra. The Baileyi is a wallowing species and should always be afforded the provision of a substrate which allows it to exhibit its natural behaviour.

The depth of the sand should always match the depth of the fish's body. It is recommended to start as shallow as possible and gradually increase the depth as the fish grows. This fish will disturb the substrate on a regular basis by moving from place to place within the sand, but it is recommended that the keeper regularly stirs up the substrate to stop the sand from ‘compacting’ and to prevent the build-up of anaerobic bacterial populations.

Gravel and plant soil/substrate is unsuitable for the Baileyi and may cause injury if the fish attempts to wallow in it. Any sharp/course pieces should be avoided/removed.