Sea Apple (Pseudocolochirus violaceus) Care Guide
Pseudocolochirus violaceus is a colourful filter-feeding sea cucumber that can release lethal holothurin toxin, suited only to experienced keepers.
Compiled by Aquairi from published sources · Published · Updated
Overview
The Sea Apple is a filter-feeding sea cucumber of the family Cucumariidae. Per Wikipedia, the Australian form has a primarily purple body, red feet, and purple and white tentacles. It is among the most visually distinctive sea cucumbers, but it carries a serious toxin risk that makes it unsuitable for community reef tanks.
Taxonomy
- Family: Cucumariidae
- Order: Dendrochirotida
- Genus: Pseudocolochirus
- Scientific name: Pseudocolochirus violaceus
- Common synonyms: traded as Pseudocolochirus axiologus (Australian Sea Apple)
Habitat
The species occurs in Indo-Pacific waters, where it lives in reef environments among other invertebrates. It anchors with tube feet to rock or substrate and extends its feeding tentacles into the current.
Tank requirements
- Minimum tank volume: 200 L (dedicated species system recommended)
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- Salinity: 1.024-1.026 SG
- dKH: 8-11
- Adult size: 15-25 cm; Wikipedia reports up to about 20 cm
- Lifespan: 5-10 years
Diet
The Sea Apple is a filter feeder that consumes plankton. According to Wikipedia it alternately brings each tentacle to its mouth, scraping off the captured plankton, and usually feeds at night when its delicate tentacles are less at risk from predators. In captivity it depends on regular dosing of phytoplankton and fine suspended foods.
Compatibility
Although peaceful and not a predator, it should be kept alone or in a dedicated system. It is not reef-safe in the practical sense because of its toxin: any tank mate able to nip it raises the risk of a toxin release. A solo display is recommended.
Breeding
It is a broadcast spawner. Captive reproduction is regarded as expert-level and is rarely achieved in home aquaria.
Pseudocolochirus (Sea Apple) Breeding Guide
Overview
The sea apple (genus Pseudocolochirus) is an Indo-Pacific filter-feeding sea cucumber that reaches about 20 cm in length. The Australian form has a primarily purple body with red feet and purple-and-white tentacles. It feeds primarily on plankton, which it filters from the water with its tentacles, alternately bringing each tentacle to its mouth to scrape off captured food.
Reproductive Mode
Like other holothurians, sea cucumbers most commonly reproduce by releasing sperm and ova into the ocean water as broadcast spawners, with separate sexes in most species. Species-specific spawning data for Pseudocolochirus is not documented in the consulted sources, so only the general holothurian pattern is stated here.
Sexual Reproduction
Sea cucumber development generally proceeds through planktonic larval stages: a ciliated auricularia, followed by a barrel-shaped doliolaria, and then a pentacularia in which the tentacles appear. This extended planktonic phase is the route to new juveniles in the wild.
Common Challenges
The sea apple is not bred in home aquaria; planktonic larval rearing is beyond display-tank conditions. More importantly, sea apples release the toxic saponin holothurin when stressed, and this toxin can poison other aquarium inhabitants, which makes the animal hazardous in a community system.