Histories

The fish that are reared come from the eggs that survive and are not devoured. Those fish that are caught while swimming seawards show bruises on the left side of their heads; those that are caught returning, on the right side.

This happens because they keep close to the left bank as they swim seawards, and keep to the same bank also on their return, grazing it and keeping in contact with it as well as they can, I suppose lest the current make them miss their way.