The expression El pez que se muerde la cola is very common in Spain. It literally means the fish that bites its own tail, and is used to describe very complex situations from which there are no way out. The metaphor of a fish biting its own tail represents lack of movement and consequently, the inability to progress. The fish is trapped, blocked, stuck; it has no way to go. In general, the individual caught in these types of situations has options, but none of them provides him or her with the desired outcome. The circumstances that surround the individual in these dead-end situations are beyond his or her control, that is to say, he or she has no power whatsoever to break out of them. It is always a no-win situation because there is no possible way around it. The English expression Catch-22 is a perfect match for the metaphor described by el pez que se muerde la cola. These expressions are about terms and/or conditions that exclude or contradict one another.
A situation of el pez que se muerde la cola:
A situation of el pez que se muerde la cola: