This sign was spotted in an aquarium in Helsinki, Finland. It depicts two somewhat stylised icons of fish bearing teeth and looking angry [sic]. The text below states in Finnish, Swedish and English that "Danger! Piranhas! Do not put your hands into the tank!" The three languages express this almost identically, though we note that the Swedish version is advising, a bit more passively, that "No hands in tank!" rather than saying that hands shouldn't be put there.
What drew my attention here the most were the teeth. Going through some Wikipedia images of Piranhas seems to indicate that their teeth are not actually quite that big. Furthermore the upper piranha even seems to stare at the viewer, with and "angry eyebrow shadow" which piranhas don't really have with mouth agape to take a bite.
Admittedly, these are simplified cartoon drawings of piranhas, but still I get the feeling that they have been anthropomorphized a bit here to convey the idea that they are not only dangerous but actively mean. Which is presumably a good thing for a place where children are near their tank.
Like mentioned last week I find these kinds of warnings of danger or violence curious. Unlike the dog sign last week, this is less of a threat and more of a genuine warning, but I still feel there is a similarity here in how these are wild animals who might bite regardless of societal rules?
In general, I guess teeth signal something animal and primordial, not bound by rules, authority and law?