JDOE wrote:
In article ,
"Connaisseur" wrote:

A Rainbow is a landlocked Steelhead...;-))

What is resident rainbow in a anadronymous waterway then? A rainbow
that could go out to ocean but doesnt?

Actually, it's a steelhead that could go out to ocean but doesn't.

The common names are great sources of confusion; they only reflect
different "life forms," different "life history traits" of the species,
and these are far from immutable.

From the evolutionary perspective, a rainbow *is* a resident steelhead,
in the sense that the anadromous life form came first. Some populations
have become landlocked over time, due to geological changes. Others are
not physically landlocked, but although they have access to the sea,
they don't go. It is not unknown--where there are both resident and
anadromous populations of O. mykiss in the same river--for the offspring
of "steelhead" to remain resident and offspring of resident fish to
smolt and migrate to sea.