Redsides....what are they?

[mandinga]

I went home last night and opened a book titled "americas 100 best trout rivers" it is a book put out by trout unlimited...

It has the big D of course listed as one of the best in the country.

In a paragraph near the end of the article the author refers to redsides and identifies them as...and I quote "a native strain of a rainbow and cutthroat..."

could this be a misprint?

let the games begin

[Abalone]

I really believe that " Redside" is a slang for a purely native Rainbow trout species.
They use that term on trout in other states also.

Coastal Cutts do Cross breed with Rainbow trout so naturally as the Deschutes does run into the Pacific Ocean there will be some mix. I see the red slashes on fish in many places I wouldn't expect them. What differeniates them for me besides the red Slashes is the distinct spotted pattern of the Cutthroat.

I beleive that there are no harder fighting fish then a native Rainbow trout ( Deschutes Redside ) anywhere.

You really get spoiled if you have caught many of them. Everywhere else you go the fish feel whimpy.......

[rock bottom]

I beleive that there are no harder fighting fish then a native Rainbow trout ( Deschutes Redside ) anywhere.

You really get spoiled if you have caught many of them. Everywhere else you go the fish feel whimpy.......

I agree those fish are great fighters. I have also caught the redsides out of the Mckenzie and they fight well too.

[Chromaflage]

This is really a good question. I've fished the Deschutes for many years and as far as trout, I've always thought, and still do to this day, there are two general subspecies in the river - maybe more. I may be mistaken, because I'm no biologist, and this is based purely on observation. Within the same water/hole/area/etc., I have caught what seems to be different kinds of trout: 1. those beautiful green-backed fish with the dark red stripe down the lateral line - what I refer to as redsides; and, 2. bright shiny trout like this one:



So, are the same, but in different life stages? Are there different subspecies? Maybe someone here can answer that. I'm just amazed at how different some trou are in that river.

CrF

[SSPey]

I was told that Deschutes rainbows are genetically distinct from the steelhead. This person (fish bio) thinks that a landslide or similar event may have cut off anadromous fish migration, then the fish remaining above evolved in isolation into a strain unique of Deschutes R. redsides

Does not apply to McKenzie

[Riverkeeper]

You guys need to do your homework.
Check out Salmon and Trout of North America by Mark Behnke. He is the expert on taxonomy of North America's native trout.

I'm too lazy to retype any of Behnke's book here, but I found some secondary literature on the web that deals with his work on the subject:



The Columbia River redband trout Oncorhynchus mykiss gairdneri, a subspecies of rainbow trout Oncorhynchus mykiss, is native to the Fraser and Columbia River drainages east of the Cascade Mountains to barrier falls on the Pend Oreille, Spokane, Snake and Kootenai rivers (Allendorf et al. 1980; Behnke 1992). Logging, mining, agriculture, grazing, dams, over harvest and hybridization and competition with other trout contributed to the decline of redband trout abundance, distribution and genetic diversity in the Columbia River Basin (Williams et al. 1989; Behnke 1992). Consequently, many populations are restricted to isolated headwater streams that may serve as refugia until effective conservation and rehabilitation strategies are implemented. Long-term persistence of these populations is threatened by loss of migratory life history forms and connectivity with other populations which is critical to maintaining genetic diversity and dispersal among populations (Rieman and McIntyre 1995).

In response to population declines, resident forms of redband trout are considered a species of special concern by the U.S. Fish and Wildlife Service, American Fisheries Society, and all states throughout their historic range (Idaho, Oregon, Washington, Nevada, California and Montana) and are classified as a sensitive species by the U.S. Forest Service and the BLM. Despite their broad distribution, few strong populations exist. Known or predicted secure populations inhabit 17 percent of the historic range and 24 percent of the present range (Lee et al. 1997). Furthermore, Lee et al. (1997) reported that only 30 percent of the watersheds supporting spawning and rearing populations were classified as strong populations. Consequently, populations in Oregon and California have been petitioned for listing under the Endangered Species Act (ESA). The California petition is currently under review and the 1999 petition to list the Great Basin redband trout in Oregon was deemed unwarranted at this time.

The Columbia River redband trout is considered a subspecies of the rainbow trout Oncorhynchus mykiss evolutionary line (Behnke 1992). Ancestral redband trout probably reached the Sacramento-San Joaquin basin from the south during the second half of the Pleistocence Epoch and penetrated the Columbia, Fraser and Athabasca river basins between 30 and 50,000 years ago (Behnke 1992). Presently, rainbow trout classification recognizes a single species O. mykiss, yet in the past many species were recognized. Behnke (1992) separates rainbow trout into the following three separate evolutionary significant groups: 1) the redband trout of the Sacramento, Kern, and McCloud Rivers in California, 2) the redband trout of the Columbia and Fraser River basins located east of the Cascade Mountains to barrier falls on the Kootenai, Pend Oreille, Spokane, and Snake rivers and 3) coastal rainbow trout. Under this taxonomy, all redband trout of the Columbia and Fraser River basins are classified as O. mykiss gairdneri.

This subspecies is genetically and morphologically differentiated from coastal rainbow trout. Morphological characteristics of distinction include the presence of vestigial basibranchial teeth, larger spots, more elliptical parr marks, fewer pyloric caeca, yellow and orange tints on the body, a trace of a cutthroat mark, and light colored tips on dorsal, anal, and pelvic fins (Behnke 1992). However, genetic techniques (e.g. protein electrophoresis) provide the only method to correctly identify this subspecies as unique from other salmonids.

Columbia River redband trout exhibit a wide variety of life history strategies. Anadromous stocks of redband (steelhead) trout historically migrated almost 1,600 km to the middle and upper Columbia River Drainage (Behnke 1992). Many of these stocks are now extinct due to dams impeding upstream migration. The gerrard strain of rainbow trout (kamloops) of Kootenay Lake, British Columbia, represents an adfluvial form which attains a large body size due to their piscivorous diet of kokanee salmon O. nerka and advanced size of sexual maturity. Kamloops redband trout reportedly spawn in Kootenai River tributaries in Montana downstream from Kootenai Falls (Huston 1995). Fluvial stocks occupy larger rivers and spawn in smaller tributaries. Resident forms inhabit smaller tributaries and headwater areas for their entire lives. The Kootenai River redband population in Montana supports subpopulations of the resident form (Muhlfeld 1999), although a migratory fluvial and/or adfluvial component may be undetectable due to hybridized populations inhabiting the lower portions of the drainage. Differentiation of redband trout life history forms (anadromous, adfluvial, fluvial, and resident) is undetectable using meristic counts, coloration patterns, and genetic markers (Behnke 1992). The inability to morphologically and genetically identify life history forms of Columbia River redband trout suggests that each population should be managed according to the geographic area or the site-specific life history strategy.

[BuKuBass]

The redsides that I admire most are almost black. I've cot examples of each that had either bright pink, flame orange, or a dark red stripe extending well on to the gill plate; gorgeous fish, my favorite!

[SSPey]

Behnke and his book are excellent, but not the most current. See abstract below...

Population structure of sympatric anadromous and nonanadromous Oncorhynchus mykiss: evidence from spawning surveys and otolith microchemistry

Christian E. Zimmerman and Gordon H. Reeves
Can. J. Fish. Aquat. Sci. 57(10): 2152-2162 (2000)

Abstract: Reproductive isolation between steelhead and resident rainbow trout (Oncorhynchus mykiss) was examined in the Deschutes River, Oregon, through surveys of spawning timing and location. Otolith microchemistry was used to determine the occurrence of steelhead and resident rainbow trout progeny in the adult populations of steelhead and resident rainbow trout in the Deschutes River and in the Babine River, British Columbia. In the 3 years studied, steelhead spawning occurred from mid March through May and resident rainbow trout spawning occurred from mid March through August. The timing of 50% spawning was 9-10 weeks earlier for steelhead than for resident rainbow trout. Spawning sites selected by steelhead were in deeper water and had larger substrate than those selected by resident rainbow trout. Maternal origin was identified by comparing Sr/Ca ratios in the primordia and freshwater growth regions of the otolith with a wavelength-dispersive electron microprobe. In the Deschutes River, only steelhead of steelhead maternal origin and resident rainbow trout of resident rainbow trout origin were observed. In the Babine River, steelhead of resident rainbow trout origin and resident rainbow trout of steelhead maternal origin were also observed. Based on these findings, we suggest that steelhead and resident rainbow trout in the Deschutes River may constitute reproductively isolated populations.

[Riverkeeper]

Ah ha! Interesting.

But that abstract notes only that the SH and trout in the D are reproductively isolated (in space, time, morphology, etc), not that they can be differentiated by their genomes.

Does it make this assertion later in the article?

[SSPey]

Riverkeeper, I don't know about genetic differences among these fish, I was only passing along spoken info from a colleague. I haven't read the article above, either (I'm not a fish bio). Reproductive isolation can be a critical step for genetic changes to become fixed. But I would have to imagine that opportunities for gene flow between Deschutes rainbows and steelhead do exist, however limited they may be. Perhaps the two groups are in the slow process of re-hybridizing in the wake of historical isolation and divergence. I don't know, fish and fishing are a hobby for me, not a vocation. I know just enough to misinform others.

:tongue:

In any case, genes can only be a part of the story, ever. Consider the obvious shortcomings of raising wild genes in a hatchery environment. It would seem that more than genetic information alone is needed to answer the original questions posed in this thread as well.