from
Bouvier's Law Dictionary, Revised 6th Ed (1856)
FISH An animal which inhabits the water, breathes by the means of gills, and
swims by the aid of fins, and is oviparous.
2. Fishes in rivers and in the sea, are considered as animals ferae
naturae, and consequently no one has any property in them until they have
been captured; and, like other wild animals, if having been taken, they
escape and. regain their liberty, the captor loses his property in them.
Vide Ferae Naturae. The owner of a fishery in the lower part of a stream
cannot construct any contrivance by which to obstruct the passage of fish up
the stream. 5 Pick. R. 199.