Acclimation: sea cucumbers are sensitive to changes in salinity. Acclimate it slowly by drip in a separate container, then move it without pouring the shipping water into the tank. Handle it as little as possible and with gloves: handling or relocating it can by itself trigger the release of holothurin.
Setup: an established reef tank with live rock; it usually settles where flow is moderate to strong. Sources disagree on volume: Reef Builders considers a tank from 10 gallons (about 38 litres) enough for this small species, while Meerwasser-Lexikon gives about 500 litres. A larger tank dilutes toxins better after an accident.
Fit every pump, powerhead and overflow intake with a large, securely fixed strainer: according to Rob Toonen, most 'cuke nukes' happen when a sea cucumber is sucked in and shredded. If it happens anyway, remove the animal at once, make a large water change, increase skimming and add activated carbon.
Tankmates and sensitivities: avoid fish that nip tentacles and do not keep too many filter feeders together. Like other invertebrates, it tolerates neither copper treatments nor high nitrate; never put it in a copper-treated tank, not even in quarantine. Splitting in two can mean stress as much as good health.
For you: sea cucumber toxins (saponins such as holothurin) irritate skin and mucous membranes; eye contact can cause serious injury, including blindness in reported cases. Wear gloves when you work in the tank. Water: aim for 22 to 25.5 °C, a specific gravity of 1.023 to 1.025, pH 8.1 to 8.4 and 8 to 12 dKH.
