Purple spot mantis shrimp (Gonodactylus smithii) care guide

Group

Shrimp

Other names

Smith's mantis shrimp, Purple spot smasher, Smasher mantis shrimp

Family

Gonodactylidae

Origin

Tropical Indo-Pacific coasts: eastern Africa, India, Australia, Guam and south of Japan; reef flats to about 60 m

Water

saltwater

Temperature

22–27°C

pH

8.1–8.4

Hardness

dKH 8–12, SG 1.023–1.025

Minimum tank

75 litres

Care level

intermediate

Temperament

aggressive

Reef safe

with_caution

Care

The purple spot mantis shrimp is a smasher mantis shrimp from Indo-Pacific reef flats. It has a purple to maroon spot ringed with white on the raptorial claws, green and red claws and yellow antennal scales. Animals from below 10 m tend to have maroon rather than purple spots. Most are around 6 cm long. Mantis shrimp are not true shrimp but stomatopods, and this one was the first animal found to see polarised light by rotating its eyes, which move independently. Tank set-up: a species tank or a tank planned around it, 75 litres or more, with plenty of live rock rubble and a sand bed, and a ready-made burrow such as a short length of pipe or a hollow rock. It lives in burrows dug into coral rubble and live coral. Its club-like claws strike hard enough to smash shells and stun prey, and large smashers can crack glass, so many keepers use thick glass or acrylic. Keep one per tank. Hitchhiker note: small mantis shrimp often arrive unseen on live rock. If you hear loud clicking at night and snails, crabs or small fish vanish, a mantis shrimp may be the cause. Unlike the larger types it can be a rewarding pet in its own tank, so catch it with a baited trap and rehome it rather than killing it. Water: tropical reef conditions of about 22–27 °C, pH 8.1–8.4, dKH 8–12 and specific gravity 1.023–1.025. It is hardy once settled. Behaviour: an aggressive, intelligent predator that watches its keeper and learns feeding times. It defends its burrow with threat displays. Copper: copper-based medicines are toxic to shrimp, snails and most invertebrates, and some plant fertilisers carry copper too. Never treat a display tank holding this animal with copper; treat fish in a separate hospital tank, and drip-acclimatise new arrivals slowly. Our sources cover its biology but not its aquarium care; the figures are general guidance, not from a source. Sources: Wikipedia (en.wikipedia.org/wiki/Gonodactylussmithii). Checked October 2026.

Diet

Carnivore. In the wild it eats fish, snails, bivalves, crabs and other crustaceans, smashing shells with its claws. Offer whole shell-on foods such as live or frozen shore crabs, snails, mussels, clams in the shell and shrimp several times a week; hard foods help keep its claws worn and healthy.

Breeding

Breeds year round in the wild, more in warmer months. Pairs are mostly monogamous; the male leaves after mating and the female guards her eggs. Larvae drift through seven stages lasting up to about 38 days in the last stages before settling. Captive breeding is very rare and needs a dedicated larval set-up.

Compatibility and tank mates

Not safe with snails, hermit crabs, crabs, shrimp, clams or small fish, which it will hunt and smash. It does not eat corals, so a reef of corals without a clean-up crew can work, but it is reef safe only with caution. Keep one per tank; large fish may bother it, and it may injure fish that come near its burrow.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.