You are here:   Home » Education » Angler Education » Fish Terms Glossary » Glossary S

Glossary S


The way in which most fish reproduce; female lays the eggs and the male fertilizes the eggs with milt.

species of special concern

A classification applied to many native fish (recognized by the State of Montana) whose populations have declined in number and size. These fish are not threatened or endangered, but may require special management. Examples of species of special concern in Montana include paddlefish, westslope and Yellowstone cutthroat trout, arctic grayling and the blue sucker.


The time period in which a fish stays at the mouth of a tributary stream (to meet its mate) in which it plans to spawn.


Mineral (rock) or organic (plant) material at the bottom of a stream. The order of the following substrate types is from the smallest particles in the stream, to the largest particles.

Sand - Substrate particle between 0.062 and 2 mm in size.
Gravel - Substrate particles between 2 and 64 mm in size, good for spawning.
Cobble - Substrate particles between 64 and 128 mm in size, good for spawning.
Boulder - Substrate particles greater than 25 cm in size.