Montana Field Guide

Largemouth Bass - Micropterus salmoides

The largemouth bass is the largest and most widely acclaimed gamefish in the sunfish family. Largemouth are true warmwater fish, thriving in temperatures up to 90 F in their native southeastern U.S. The largemouth bass may be the most widely introduced species in North America and are now found virtually all across the continent as well as east and west of the Divide in Montana. Another spring spawning nest-builder, the largemouth bass prefers habitat that is very warm, such as weedy ponds or sloughs. They are seldom found in rivers or in waters deeper than 20 feet. An aggressive and opportunistic surface-feeder, largemouth bass are primarily fish-eaters. They also will eat nearly any other water-borne animal on occasion. The Montana record largemouth bass is a little over 8 pounds, but the world record is 22 pounds. Largemouth bass do well in many marginal trout ponds but are subject to winterkill and often need to be restocked.

Length of the longest dorsal spine at least twice the length of the shortest dosal spine at notch. Young have a bicolored tail, the rear being darker than the front.

Montana Range

Clear mud-bottomed lakes and stream backwaters. Seeks areas with comparatively warm summer water temperatures and ample aquatic vegetation.

Adults feed mostly on fishes. Minnows and suckers are the most frequent foods. Frogs and aquatic insects are also eaten. Young first feed on plankton.

Grows slowly in Montana because of cold water temperatures.

Sexually mature in 3-5 years. Spawns May-mid July. Eggs and fry cannot tolerate temperatures below 50 degrees F. Usually spawns at 62-65 degrees F. among emergent vegetation in quiet bays.