it depends... is it a salt water or fresh water type of fish. if it is a fresh water kind there is something wrong with it but if it is a salt water kind apparently some have been found to swim backwards for no apparent reason.
Its own desire or need to swim backwards.
no my fish swim backwards all the time,my other guppies always chases it .
NO, it is not a challenge because it could happen.
An artificial penis, oh wait thats a dildo.. A fish that swims backwards
it swims?
Any kind of fish that swims in front of them while they are hungry
a gold fish swims in a fish tank or the sea.It Swims I The Water And Eats Fish Food
They just swimmin about.
because it swims
It is a fish that swims and if you are allergic to any type of fish then just don't eat any type of fish
goldfish
Shark fish
one of mine is NOW NO SWIMS ON MON