What Does It Mean If Fish Fins Are Down. Spines, when held stiff, make small fish much harder to swallow. Sometimes it also means theyre going to have babies, right now she is and she was curling up.
There is a chance that your fish may be sick if it’s at the bottom of the tank. According to this website, your fish may not respond to treatments but there is no harm in trying. Sometimes the fins (including the tail fin) get damaged due to fish tank decorations, fish fights, and a disease called fin rot.