Actually Canary Blennies are venomous like paintballer states
The Canary Fang Blenny is also known as the Oualan Forktail Blenny, or Canary Blenny. The Canary Fang Blenny is aptly named, being a solid vibrant yellow. Males are generally larger than females and experience a succession of color changes when breeding.
The Canary Blenny can make a wonderful addition to many community or reef aquariums. With their relatively peaceful natures and their brilliant colorings, these Blennies can make interesting captives.
This blenny needs a minimum tank of 30 gallons with live rock for hunting and grazing in order to thrive. It is best to keep only one per tank unless a breeding pair is maintained. If attacked by other fish, the Canary Fang Blenny will retaliate by biting the inside of the mouth of the attacker. The Canary Fang Blenny is considered venomous and should be kept only with caution around children having tank access, since it may perceive fingers as an attacker and deliver a similarly painful bite.
They are equipped with a pair of venomous fangs, which they usually use as a defensive measure against predation. These fangs can (and often do) deliver a painful bite, and it is advisable to avoid reaching into your Blenny's aquarium or hand feeding it. Canary Blennies are considered to be reef safe. They normally do well in community environments as long as plenty of space and hiding places are provided. However, they normally do not get on well with other Canary Blennies, and unless you are attempting to create a mated pair, it is advisable to keep only one of these fish per aquarium. One of the most charming traits of the Canary Blenny is its apparent boldness; these fish seem to spend little time hiding and often swim in open areas. Their bright, usually yellow, color can really add interest to an aquarium. Often, Canary Blennies are added to aquariums containing live rock. This allows them the opportunity to perform the natural grazing behavior they would show in the wild, and the material they glean from this rock provides an important part of the Canary Blenny's diet.