That Fish Blog – Aquarium Advice and Information

Almost every aquarist will feel the sting from a cnidarian (anemones, jellyfish, ect.) at some point or another. For some, it can just be a mild annoyance, but for others it can be downright painful or even dangerous. The correct treatment depends on what you were stung by and how sensitive you are to it.

Cnidaria is a large phylum (one of the broadest scientific classifications) and includes jellyfish, corals, anemones, and hydroids that aquarist might encounter in their tanks. Cnidarians have specialized stinging cells known as “nematocysts” or “cnidocysts”. These cells can be used as defense mechanisms or to catch prey. Some are harmless to people, but effective on the cnidarian’s targeted prey.  Some can be lethal to anything they touch – the Sea Wasp, a type of box jellyfish, is touted as the most venomous marine animal ever and is usually fatal. Different types of nematocysts have different functions and one animal can have more than one type of nematocyst at a time, but all function essentially the same way. Read More »