Oncorhynchus aguabonitaGolden trout

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Geographic Range

The golden trout is found in high altitude fresh bodies of water in the western area of the United States. Specifically, this species can be found in Wyoming, Idaho, Washington, and most abundantly in California, where it was first discovered.

Habitat

Golden trout occupy only high altitude fresh water lakes and rivers, usually in scenic mountain areas that are highly inaccessible and can only be reached by horseback riding or backpacking. These altitudes can range anywhere from 9000-12000 feet. The water in which the fish dwell is usually of very low temperatures and is of great beauty, hence, the name, aguabonita. The waters contain little weed growth.

  • Aquatic Biomes
  • lakes and ponds
  • rivers and streams

Physical Description

Golden trout are small sized members of the trout family with an overall golden color and orangish-red stripes along the side. The rear portion of the body right before the tail is often speckled with dark spots, and so is the dorsal fin. Small scales are also a distinguishing characteristic.

  • Range mass
    0.02 to 5 kg
    0.04 to 11.01 lb

Reproduction

The female golden trout's egg development starts early in their short growing season. The egg is almost completely ripe when lowering temperatures arrest development at the onset of winter. The fish are then ready to spawn the following spring. Provoked by the melting snow and thawing streams, the spawning routine, which starts anytime between March through July, begins its process, depending on weather conditions and elevation. Reproduction is sexual with external fertilization. The female lays her eggs in specific areas, and the males then come and fertilize them. The development of the egg, hatching, and early growth stages are virtually the same as in the other spring spawners.

Behavior

Golden trout are primarily social organisms, traveling in small schools. There are no apparent hierarchical systems within populations. They are active all summer and can be seen rising almost every day. Because this species is anything but aggressive towards other fish, it is dominated by most other species. In fact, golden trout can rarely be found in waters that are occupied by any other fish, including other trout. This may explain why goldens dwell only in very remote areas at high altitudes.

Communication and Perception

Food Habits

The diet of the golden trout consists mainly of surface water-dwelling insects, principally small ones such as caddisflies and midges. Small crustaceans such as tiny fresh water shrimp as well as some terrestrial insects contribute to the diet as well. However, small insects, either in larvae or fully developed form, floating on the surface compose most of the natural food of this species. To feed, the trout opens its gills and hinged mouth and inhales its prey whole in the water. The water is then pushed back out of the gills, acting much like a filter, leaving only the food in its mouth. The primary feeding season is from May through September, because there is a scarcity of insects found during the colder season.

Economic Importance for Humans: Positive

The main benefit is that goldens attract fishers and are prime food fish, either pan sauted or smoked. It is of little interest to tourists unless the tourists are fishing fanatics eager to catch a rare golden while enjoying the beautiful area in which the trout occur.

Conservation Status

The California Department of Fish and Games Committee on Threatened Trout has been active in working to protect and enhance the survival of the species. Attempts to widely stock the western states have been made but many populations do not last long. The population of golden trout in the South Fork Kern River was reduced by the presence of brown trout. Golden trout are now more abundant, however, than they have been in the past.

  • IUCN Red List [Link]
    Not Evaluated

Other Comments

Originally, aguabonita trout were thought to be related to the Colorado River cutthroat trout, but were later recognized as a close relative of the rainbow trout. Another common name that has been used is the Volcano Creek golden trout, which refers to the place in which it was first recognized. A subspecies of golden trout that was given full species status in the early 1900s is Little Kern golden trout, Oncorhynchus aguabonita whitei. The record for the largest golden trout is 11 pounds, caught in Wyoming.

Contributors

Wendy Wimble (author), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

tactile

uses touch to communicate

References

Behnke, R. J. 1992. Native Trout of Western North America. American Fisheries Society, Maryland. p. 191-192.

Mellane, A. J. 1965. Standard Fishing Encyclopedia. Holt, Rinehart and Winston, Inc. NY. p. 380.

Robins, R. C. 1991. Common and Scientific Names of Fishes from the United States and Canada. American Fisheries Society, Maryland. p. 28.

Stolz, J. and J. Schnell. 1991. Trout: The Wildlfe Series. Stackpole Books, Pennsylvania. p. 280-285.