What kind of urchin and sea cucumber??

[Joshsmit56001]

I am not sure what kind of Urchin I have or what kind of sea cucumber I have. I am posting pics of both. Any help would be great. Also if you could tell me if they are reef safe too that would be great. I am only really worried about the urchin though. Here are the pics.

 

[Mr.5150]

Hey,
I'm not to sure on this but maybe i could help,
I think the cucumber is a tiger tail (Holothuria): can be useful/safe in reefs, toxic or harmful to fishes.
I think the urchin you have is probably a rock urchin: ornamental, destructive or harmful tto corals and is not reef safe.
Hope that was helpful,
Those are my guesses, can anyone confirm this?

 

[steve-s]

The cuke is a black knoby Stichopus chloronotus. They do best is sandy substrate tanks and should only be housed in tank that are mature and have enough surfcae substrate to allow for constant grazing. If the tank is too young, the cuke can easily starve and food supplimentation is near impossible. They are indeed toxic although less so than most others. If in a smaller tank, they could easily nuke the water quality causing a fair amount of animal loss.

The second looks like a type of rock boring urchin Echinometra mathaei and will most likely make short work of your coralline over time...

Moved to Saltwater- Identification

Cheers
Steve