nudibranch or sea hare?

[Fishieness]

I also found out that they can poison off a tank if they die, especially in smaller tanks without a lot of water to dillute the toxic stuff. I think this is becasue they can eat poisonous creatures without being harmed, but store all of that poison in their body so when they die, it leaches out into the tank. The only part I was unsure of about that then is if the same would hold true if they were never around a poisonous food source.

Hope that helps a little bit.

many species can actualy do this. The toxin is made. IT isnt because they eat toxic creatures. They produce a tetratoxin... or maybe a palytoxin.... either way, it is a defence mechanism to prevent animals from eaating it. But because they are so light and frail, the demise of many many nudibranchs often come from getting caughted or sucked into powerheads. They you may get a tank crash from the toxins depending on the type. and your skimmer would definatly go nuts also