Aquarium Livestock Pet Care Guides

Sea Apples & Sea Cucumbers

Natural Habitat

Indo-Pacific, Atlantic

Tank Temperature




Specific Gravity


Tank Requirements

Requires pristine water conditions; ample food source.


Planktivore/ filter-feeder; most species should be fed invertebrate food 2-3 times a week. Sandsifting cucumbers will feed on detritus in and on the substrate.


May use tubed feet to cling onto surfaces. Some extend feeding tentacles to catch food. May expel internal organs when threatened.


Community and Invert Safe; Reef Safe, with caution! Be sure not to house them with tankmates that will pick at their tentacles.

Species Overview

Most Sea Cucumbers offered in the aquarium trade are filter feeders, typically from genera Pentacta, Colochirus, and Pseudocolochirus, among others. They extend frilly feeding tentacles into the water to catch free-floating planktonic foods and pull these food items into their mouth to feed. The cucumber can be target-fed with various filter-feeder foods at least 2-3 times a week when these tentacles are extended. Most also have very strong tubed feet that they use to attach themselves onto rockwork or the sides of an aquarium. If the cucumber is moved, these tubed feet may be left behind but will grow back with time.

Holothuria species are best known for their reputations as sand cleaners. These cucumbers move along the bottom and use their sticky oral tentacles like mops to collect detritus, bacteria, microalgaes and other food particles. Many will burrow into the substrate or extend their bodies out from the protection of rockwork to feed. With the exception of very large systems, it is best to limit cucumbers to one per tank. Multiple cucumbers can often deplete an aquarium of their food source and lead to the cucumbers starving unless fed heavily.

Sea cucumbers can be harmed if they are trapped or pulled into filter intakes or overflows. Some fish may also pick at their bodies or feeding tentacles so tanks and tankmates should be chosen with care. If a cucumber is stressed, they may expel their internal organs as a stress response. As long as the cucumber is healthy otherwise and the cause of the stress is removed, these organs can grow back and the cucumber can survive. Most cucumbers also produce "holothurin toxins". These toxins can range from a mild irritant to deadly to aquarium residents. Sea Apples have notoriously strong toxins and can wipe out an entire tank. Always choose cucumbers and tankmates with care and monitor any stress to the cucumber.

We always suggest that you do further research before adding a new pet to your tank. What we have provided for you are guidelines and suggestions. If you have any further questions or concerns, please contact our fish room at 717-299-5691 ext. 1213 or

Recommended Items

Invertebrate Food
Aragonite Sand