I'm sorry, I've not heard of a particular story named 'sina and the eel' before. It could be a unique story written by an individual or a story from a very specific cultural or regional background.
As I don't know the exact 'sina and the eel' story, we can consider different storylines. It could be that Sina lives by a river and the eel is a regular part of the ecosystem he observes. One day, an event occurs that makes the eel special. For instance, a drought is coming and Sina notices that the eel is acting strangely. He follows the eel and discovers a hidden water source that could save his village. So, the eel becomes a symbol of hope and discovery in this potential story.
Without more details, it's hard to say much about the 'sina and the eel' story. It might be a story where Sina is on a journey and the eel plays a crucial role. Maybe the eel is a magical creature that helps Sina find his way through a difficult situation, like guiding him through a maze - like forest or leading him to a hidden treasure. But again, this is just speculation.