Anyone have experience with C. varians, the legendary nudibr

[nick danger]

An LFS in my city just got some small C. varians, the black and blue nudibranch that ostensibly eats red flatworms. They are about an inch snout-to-tail.

Does anyone have personal experience with these? My questions are:

1) Do they in fact eat red flatworms?

2) Do they die after depleting the tank?

3) Would a small one be able to finish off a 75g infested with the worms, or would the worm population multiply quickly enough to keep the slug alive?

4) Assuming the flatworms eat cyanobacteria (true? false?), would my tank, after freeing itself from the red flatworm plague soon after suffer a cyano plague?

Thanks in advance!!

ND

 

[Anonymous]

1) Do they in fact eat red flatworms?

Yes.

2) Do they die after depleting the tank?

If not sooner. They have a very short lifespan naturally, but the presence of overflows, powerheads and pumps tends to shorten it even further.

3) Would a small one be able to finish off a 75g infested with the worms, or would the worm population multiply quickly enough to keep the slug alive?

Either the slug will get ahead of the flatworms, wipe them out and die of starvation, or the flatworms will multiply faster then can be consumed and the slug won't even appear to make a dent.


4) Assuming the flatworms eat cyanobacteria (true? false?), would my tank, after freeing itself from the red flatworm plague soon after suffer a cyano plague?

No idea.

Other things to be aware of: there are slugs with the same coloration and body markings as chelidonura varians, but not the same dietary habits. Some are predatory. I wouldn't want to bet money on the ones you're looking at being correctly identified.

C. varians is not found in large numbers in nature and has a short life span. It is not a species where captive breeding is likely to be successful (Dr Bill Rudman, per a brief conversation I had with him). This is an animal that largely should be left in the ocean.