Hysterocarpus traskii pomo
PLEASE NOTE: Most of the photos and information shown here are for the species Tule Perch, of which the Russian River Tule Perch is a sub-species.
Tule Perch are most often found in low-elevation lakes, streams, and estuarine environments. They typically require cool, well oxygenated water. These fish prefer water temperatures below 22°C and are scarce in water that exceeds 25°C. Tule Perch have a high salinity tolerance and have been found in water with a salinity as high as 30 ppt. Within a river or stream Tule Perch tend to occupy deep pools that have complex cover in the form of aquatic and overhanging vegetation. They feed on invertebrates, plants, and zooplankton, mostly by swimming along the bottom of the stream. The perch may move into faster water for feeding by occupying small eddies and backwaters behind rocks and boulders. Tule Perch tend to share habitat with other native fish. In lakes Tule Perch favor deep water and areas where a slight flow might exist from water entering and exiting the basin. In addition these fish are found near tules in areas where the lake floor is made up of gravel and or sand. Tule Perch may form shoals or schools, and are often found associated with centrarchids. While the perch focus their feeding on the bottom of a lake, they may also forage in the water column. Dietary components in various types of water may include shrimp, crabs, clams, chironomid midges, and aquatic insects. Tule Perch have a relatively elaborate reproductive cycle. Male perch may “court” females in order to attract them for breeding. Males then inject sperm into the female with a modified anal spine, and each female may mate with multiple males. While the sperm may be injected in July-September, the sperm is not released to fertilize within the female till January. Young perch then begin to develop within her, slowly at first, and more rapidly in the final two months. In around May or June the female bears 10-60 live fish. The number of young produced increases with body size and may vary from one environment to another. Tule Perch grow most rapidly during the first 18 months of life, and may live up to 7 or 8 years. The majority never exceed 16 cm SL nor do they live longer than 5 years.
Video of Tule Perch in Russian River, CA:
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