Stenorhynchus seticornis

Acclimation: drip-acclimate it (one to two drops per second) until the salinity in the bucket matches the tank.

Aquascape: an established tank with plenty of rock, cracks, caves and overhangs where it spends the day. A tank of 110 litres or more is advised: in a small volume it becomes more aggressive and predatory.

Tankmates: it is territorial and does not tolerate its own kind; keep only one per tank. Avoid small, slow bottom-dwelling fish or tiny gobies, small shrimp and other crabs. Also avoid fish that eat crabs and shrimp (pufferfish, Picasso triggerfish, hawkfish).

Moulting and sensitivities: after a moult it hides for a day or two and is vulnerable; leave the cast shell, which it may eat to recover minerals, and keep calcium and alkalinity in check. It does not tolerate copper treatments. Water: 22 to 25.5 °C, specific gravity 1.023 to 1.025, pH 8.1 to 8.4, alkalinity 8 to 12 dKH.

In the wild it is mainly a nocturnal scavenger that occasionally eats small animals, in particular small tube-dwelling feather duster worms and other reef invertebrates.

In the aquarium it actively hunts bristle worms, including at night, which explains its reputation as a controller. It also accepts meaty food, flakes and pellets and picks up leftovers and detritus. Regular, varied feeding lowers the risk of predation on tankmates without removing it; when short of food it may nip mushrooms, polyps or small fish. Avoid overfeeding, which loads the tank with nutrients.