The golden trout is a brightly-colored variety of rainbow trout found in the streams of central California in the US. Designated as the California state fish in 1947, this trout is a threatened species due to overfishing, poor ecological management, and competition with non-native species. Two sub-species, the California golden trout and the Little Kern golden trout, inhabit streams above 10,000 feet (3,048 m) and freshwater lakes to which they have been transported.
The golden trout ranges in size from 5 to 7 inches (12 to 17 cm) in length. The term “golden” comes from this fish’s bright yellow sides. Goldens have green backs and orange cheeks and underbellies. This trout has the greatest number of spots on its tail, back, and pectoral fins of all the rainbow trout species. This bright coloration makes them less visible in their clear, reflective mountain stream habitat, protecting them from predators.
Goldens live primarily in the clear waters of small mountain streams of California’s Little Kern and South Fork Kern River, though conservationists transported these trout to Nevada and New Mexico to keep the species viable. These fish tend to keep to a limited area of sand and gravel beds where aquatic vegetation and insects are plentiful. Goldens has few native predators besides man.
The fish spawn in the spring and summer months, primarily in the afternoon when the water is warm. Males usually become more brightly colored during breeding season. Females typically create shallow holes in the stream bed and lay between 300 and 2,300 eggs at a time. Hatching occurs about three weeks later. The young trout, called fry, keep to their hatching area for another two to three weeks. The fry expand out into the stream waters and feed on insects and vegetation until they become mature at 2 to 3 years of age.
The diet of the golden trout includes insects such as spiders, flies, mosquitoes, and beetles. When the mountain climate becomes too cold for meadow grasses, which support these insects, to thrive, the trout’s food supply is greatly diminished. This trout also eats larvae, phytoplankton, fish eggs, and other smaller fish.
Threats to the golden trout include recreational fishing, habitat encroachment, and the golden's failure to compete with introduced fish species. Habitat loss typically occurs because of livestock grazing. Goldens rely on riparian, or riverside, vegetation—grazing denudes riverbanks and mountain meadows in a concentrated timeframe that usually does not allow for timely regeneration. Non-native species such as the brook trout compete successfully for food, while the brown trout preys on the less aggressive goldens. Hybridization with other non-native trout species generally weakens the genetic robustness of this vibrantly-colored trout.