Livestock | Marine | Marine Inverts and Snails | Cucumbers

Keeping Sea Cucumbers in Marine Aquariums

Sea cucumbers are unusual but fascinating invertebrates that serve as efficient sand sifters and detritus cleaners in marine aquariums. Their slow, graceful movements and unique appearance make them a distinctive addition to established reef systems. While many are peaceful and beneficial, proper species selection and care are essential to long-term success.

General Care Tips:
Sea cucumbers require stable, mature aquariums with fine sand beds, consistent water parameters, and minimal aggression from tankmates. Ideal water conditions include a temperature of 72–81°F and a pH of 8.1–8.4. These sensitive invertebrates are best suited for well-established systems with a healthy sandbed and low levels of disturbance.

Feeding:
Most commonly kept sea cucumbers are detritivores, meaning they sift through the sand for organic matter and uneaten food. These species help maintain a clean substrate and support nutrient export. In low-nutrient tanks, supplemental feeding with finely powdered invertebrate food or marine snow may be required to support their dietary needs. Non-sand-sifting species may require targeted feeding of planktonic or dissolved organic material.

Compatibility and Behavior:
Sea cucumbers are peaceful and typically do not interact with other tank inhabitants. However, they can be injured or stressed by aggressive fish, sharp rockwork, or sudden changes in water chemistry. Certain species, especially colorful or spiny ones, should be kept with caution—if severely stressed or injured, some can release toxins that may harm fish or invertebrates in a closed system.

Popular Sea Cucumber Species:

• Tiger Tail Cucumber (Holothuria hilla): A hardy, sand-sifting species great for larger reef tanks.

• Pink & Black Sea Cucumber (Holothuria edulis): Attractive and functional; ideal for larger systems with established sandbeds.

• Yellow Sea Cucumber (Colochirus robustus): A filter-feeding species best kept by advanced aquarists with dedicated feeding routines.

• Black Sea Cucumber (Actinopyga spp.): Hardy and effective but may release toxins if injured—best kept with caution.

• Sea Apple (Pseudocolochirus spp.): Highly colorful filter feeders; beautiful but very risky in reef tanks due to toxicity if stressed.

Special Considerations:
Always introduce sea cucumbers carefully—use a drip acclimation method to prevent osmotic shock. Avoid using powerheads or overflow grates in areas where cucumbers may get stuck. Tanks with low nutrient levels or coarse substrate may not support sand-sifting species well. Regular observation for signs of stress (shrinking, inactivity, or evisceration) is important.

Summary:
Sea cucumbers are efficient scavengers that play a valuable role in cleaning sandbeds and improving substrate health. With proper care, careful species selection, and an appropriate environment, they can thrive in reef aquariums and offer both function and unique beauty. Best suited for intermediate to advanced aquarists due to their specific environmental and feeding needs.