What do cucumbers (holothurid?) eat exactly?

[LostMind]

My reef inverts book says they need a deep sand bed, but do they just eat left over food and fish wastes or do they eat algaes (diatoms, etc) or?

I am looking to clean up my sand a bit - its constantly a brown tinge from the diatoms...

[Tigger]

My black sea cucumber eats anything that is stuck to the sand.

[fredfish]

THey feed on fish poo, detritus and bacterial films that develop on sand grains. Think of it like a house pet that eats anything you drop on the floor, but thats all it needs to survive.

Fred.

[LostMind]

Sounds good so far - but does it feed on diatoms as well? How about other algaes?

[fredfish]

If if grows as a biofilm on sand grains, and some diatoms do, then yes, it will be eaten by holothurids. Macro & hair algaes, no. They are not an algae control critter. If you are looking for a generalized algae eater, look for a diedema species urchin (see the latest Reefkeeping online issue)

Fred.