Sea apple (Pseudocolochirus violaceus) care guide

Group
Other invertebrates
Other names
Australian sea apple, Sea apple cucumber, Violet sea apple, Purple sea apple
Family
Cucumariidae
Origin
Indo-Pacific, including northern Australia
Water
saltwater
Maximum size
20 cm
Temperature
24–27°C
pH
8.1–8.4
Hardness
SG 1.023–1.026
Care level
expert
Reef safe
with_caution
Flow
Moderate, indirect flow carrying food

Care

The sea apple is a colourful, filter-feeding sea cucumber with a round, oval body up to about 20 cm long, plus a crown of feathery feeding tentacles. Colours vary; the Australian form has a mainly purple body, red tube feet and purple and white tentacles. It grips rock with rows of tube feet. When stressed it can swell up with seawater to almost double its size and let the current carry it away. Toxin warning: like some other sea cucumbers, a sea apple can release a toxin called holothurin when stressed, harassed, sucked into a pump or dying, and this can poison and wipe out the fish in a tank. When disturbed it may also expel its insides. Keep powerhead and pump intakes guarded, keep a bag of fresh activated carbon ready, and remove a dying sea apple immediately. Many keepers will not risk it in a reef. Feeding guide: filter feeders like this are hard to keep fed and often starve slowly in aquariums. Sea apples catch plankton with their tentacles, wiping each one into the mouth in turn, and in the wild feed mostly at night. Display tanks rarely have enough plankton, and a sea apple that shrinks steadily is starving. Set-up: a large, mature tank with plenty of live rock, moderate indirect flow, guarded pump intakes and no fish or crabs that pick at its tentacles. The water figures are typical reef-tank guidance rather than from a source. Copper: copper-based medicines and some plant fertilisers are toxic to shrimp, snails and most other invertebrates. Never dose them in a tank holding this animal, and read the label of any treatment, fertiliser or algae remover before use. Sources: Wikipedia (en.wikipedia.org/wiki/Pseudocolochirusviolaceus). Checked October 2026.

Diet

A plankton filter feeder. Feed live or frozen phytoplankton and zooplankton (rotifers, copepods, oyster eggs, baby brine shrimp) and liquid filter-feeder foods several times a week, ideally in the evening with pumps turned down so the tentacles can catch it. Target-feed with a pipette.

Breeding

Not bred in home aquariums. Sea cucumbers spawn by releasing eggs and sperm into the water, and a stressed sea apple spawning or eviscerating in a tank can foul the water.

Compatibility and tank mates

Harmless to corals, but with caution because of its toxin. Hermit crabs, crabs, angelfish, butterflyfish, puffers and triggers often peck at its tentacles or steal food, stressing it. Best in a quiet species or very peaceful tank.

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

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