Shoalers are around 20cm long at full size. Their finspan can be 8cm, with two strong fins in front of four vestigial ones. They have a two-pronged caudal fin, and chemoreceptors on the neck and their long tail.
They have two primitve eyes on their head, which is an elongated snout. The mouth at the end has msucles which enable it to be open and closed, rasping at fanisids.
Shoalers live in great shoals of thousands, and sperm and eggs are released by both sexes in their two annual mating seasons. Fertilised eggs drift to the bottom of the sea, and develop in a small sac of membrane. A single fmeale can usually produce two hundred eggs.
Offspring are left to surive on their own by their parents. They take two weeks to grow to full size.