Oncorhynchus clarki clarki
Other names: sea-run cutthroat, harvest trout
Average size: 1-4 lbs, up to 6 lbs
Of the 13 subspecies of cutthroat trout indigenous to North America, only the coastal cutthroat is anadromous. But coastal cutthroat have complex life histories, and not all fish are anadromous. In any given body of water, some may migrate to sea, while others become resident fish. In fact, the offspring of resident fish may migrate, while the offspring of anadromous fish may "residualize."
Sea-run cutthroat spawn over a long period, from winter through May. They seek smaller streams where the flow is minimal and the substrate is small, almost sand. They prefer the upper-most portions of these streams, areas that are too shallow for other salmonids.
Most cutthroat rear in-stream for two to three years before first venturing into salt water. Emerging fry are less than an inch long, and are poorly able to compete with larger coho and steelhead fry for resources. To compensate, cutthroat fry use headwaters and low-flow areas that coho and steelhead avoid.
Unlike other anadromous salmonids that spend multiple years feeding far out to sea, cutthroat prefer to remain within a few miles of their natal stream. They do not generally cross large open-water areas. Some will overwinter in freshwater and only feed at sea during the warmer months. In rivers with extensive estuary systems, cutthroat may move around in the inter-tidal environment feeding, plus run up-river or out to sea on feeding migrations, wherever their nose tells them the food is. Protected estuaries and Puget Sound bays are excellent cutthroat habitat.
Alevin - The lifestage of a salmonid between egg and fry. An alevin looks like a fish with a huge pot belly, which is the remaining egg sac. Alevin remain protected in the gravel riverbed, obtaining nutrition from the egg sac until they are large enough to fend for themselves in the stream.
Anadromous - Fish that live part or the majority of their lives in saltwater, but return to freshwater to spawn.
Emergence - The act of salmon fry leaving the gravel nest.
Fry - A juvenile salmonid that has absorbed its egg sac and is rearing in the stream; the stage of development between an alevin and a parr.
Kype - The hooked jaw many male salmon develop during spawning.
Parr - Also known as fingerling. A large juvenile salmonid, one between a fry and a smolt.
Smolt - A juvenile salmonid which has reared in-stream and is preparing to enter the ocean. Smolts exchange the spotted camouflage of the stream for the chrome of the ocean.
Substrate - The material which comprises a stream bottom.