Yellowfin cutthroat trout

Yellowfin cutthroat trout
Conservation status
Presumed Extinct  (NatureServe)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Salmoniformes
Family:	Salmonidae
Genus:	Oncorhynchus
Species:	O. clarkii
Subspecies:	O. c. macdonaldi
Trinomial name
Oncorhynchus clarkii macdonaldi Jordan & Fisher, 1891

The yellowfin cutthroat trout (Oncorhynchus clarkii macdonaldi) is an extinct subspecies or variety of the cutthroat trout, a North American freshwater fish.

Natural history

At the end of the last ice-age boulders and clay moraine blocked off a tributary of the headwaters of the Arkansas River in what is now the state of Colorado. The two lakes which formed were named the "Twin Lakes" by the area's settlers. Both lakes held small greenback cutthroat trout from the early days of the Wild West, but in the mid-1880s reports circulated of much larger trout, up to 10 pounds (5 kg) in weight, with bright yellow fins.

Discovery and naming

In July 1889, Professor David Starr Jordan and G. R. Fisher visited Twin Lakes and published their discoveries in the 1891 Bulletin of the United States Fish Commission. They found both the greenback and what they proclaimed to be a new species the "yellowfin cutthroat". In his report Jordan took credit for the name and described the fish as follows:

Color, silvery olive; a broad lemon yellow shade along the sides, lower fins bright golden yellow in life, no red anywhere except the deep red dash on each side of the throat.

The subspecies was scientifically named macdonaldi after the US Fish Commissioner, Marshall McDonald.

Jordan's specimens were recently re-examined by the fisheries biologist Robert J. Behnke, who commented, "I have no doubt that Jordan was correct; the yellowfin trout and the greenback trout from Twin Lakes were two distinct groups of cutthroat trout".

Extinction

Until about 1903, greenback and yellowfin cutthroats survived together in Twin Lakes, the populations remaining isolated as both breeders and feeders. The end for the yellowfin cutthroat came soon after the introduction of the rainbow trout to Twin Lakes. The greenback population interbred with the rainbows, resulting in cutbows, but the yellowfin disappeared completely. The yellowfin is now extinct.

Further reading

• Trotter, Patrick C. (2008). Cutthroat: Native Trout of the West (2nd ed.). Berkeley, CA: University of California Press. ISBN 978-0-520-25458-9. 

Cutthroat trout subspecies and forms
Salmonidae
Pacific Coast	Coastal cutthroat trout Lake Crescent cutthroat trout
Great Basin	Alvord cutthroat trout† Bonneville cutthroat trout Humboldt cutthroat trout Lahontan cutthroat trout Whitehorse Basin cutthroat trout Paiute cutthroat trout
Northern Rockies	Snake River fine-spotted cutthroat trout Westslope cutthroat trout Yellowfin cutthroat trout† Yellowstone cutthroat trout
Southern Rockies	Colorado River cutthroat trout Greenback cutthroat trout Rio Grande cutthroat trout
Media related to Oncorhynchus clarkii at Wikimedia Commons

Trout and char of the world
Trout - Salmonidae
Trout of Europe and Atlantic basin Salmo	Adriatic trout Brown trout Fibreno trout Ferox trout Flathead trout Garda lake trout Gillaroo Lake (lacustrine) trout Marble trout Mediterranean trout Ohrid trout Prespa trout Riverine brown trout Sea trout Sevan trout
Trout of the Pacific basin Oncorhynchus	Apache trout Cutthroat trout Gila trout Mexican golden trout Rainbow trout
True char Salvelinus	Arctic char Brook trout Bull trout Dolly Varden trout Haddy charr Kirikuchi char Lake Char Lake trout Orkney charr Silver trout Small-mouthed char Whitespotted char
Media related to Trout at Wikimedia Commons