checked with henry and below is his reply as to if the sea hare slug is poisonous and release toxic
"Its absolutely mistaken. When stressd, the sea hare will release a harmless purple dye for defense. If sea hare die, it decompose like any other organism. only get high nutrient release which should be taken care of by the bio filter and skimmer"
moderator, not trying to flame anyone. purpose of www is people can share infos. perhaps henry can share more about this sea slug creatures with us .