It looks something like the eel spears we used to make from bamboo as kids. Yours is much slicker though. I like the metal barbs a lot. On the ones we made we'd have slightly more pronounced barbs and a short prong in the middle as well. Eels are tough beasties and used to break them fairly frequently.
For flounder we just used to use a spike driven into the end of a pole. That way you could spear them, get a hand under them to lift them up and let them just slide off the spike into a bucket. I preferred flounder to eels