The Trout Lodge hatchery folks (http://www.troutlodge.com) were early pioneers of fish breeding at their Rocky Ford facility, from which come the fish planted at Rocky Ford.
The WDFW's CTEP program has targeted planting triploids (along with regular diploid trout) at a variety of Washington lakes as a strategy to increase the popularity of trout fishing among the general population. What fisher would have a moment's hesitation deciding whether to catch a 10-inch planter or a 5-pound triploid bruiser?
I believe Bill's comment was in hopes that Rattlesnake Lake might be the recipient of such a plant. There's no free lunch and triploid stockers don't come cheap. The key is to continue to foster the catch and release ethic among all fisher, so that the return on the investment of planting large, mature triploids pays off over time with multiple catches of the same fish.
If you're interested in learning more, I've copied a white paper from Trout Lodge on triploids below.
Kent Lufkin
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Triploids In Aquaculture DNA (deoxyribonucleic acid), the molecular basis of heredity in nearly all life on earth, is most often organized into linear structures within the cell nucleus that are called chromosomes. Each particular animal or plant species has a characteristic, constant number of chromosomes. Ploidy refers to the degree of repetition of this basic chromosome number. While a majority of organisms are diploid (possessing two complete sets of chromosomes, or 2n), polyploids having more than two complete sets are sometimes observed, particularly in plants. In fact, triploids (organisms having three chromosome sets, 3n) are quite common in traditional plant agriculture. Most bananas that are sold in commercial markets are triploid, as are many ornamental flowers and trees. Perhaps the most familiar triploid plant in production today is the 'seedless' watermelon. Much less common than triploid plants, triploid animals are sometimes utilized in production situations, particularly those involving fish or bivalve mollusks.
The main advantage of triploids in any form of agriculture is that they are generally sterile. As mentioned above, most plants and animals are diploid, with each cell in their body containing two complete chromosome sets. The normal cell division process associated with growth, termed mitosis, accurately ensures that each new daughter cell receives a complete diploid complement of chromosomes. At sexual maturity, however, an alternate cell division process takes over in the cells that eventually produce the gametes, or eggs and sperm. This process (termed meiosis) involves two distinct steps, referred to as meiosis I and II, respectively. The multiple-step nature assures that each egg or sperm contains only one entire set of chromosomes (a haploid or gametic set, n). The result of this reduction division is that when the sperm and egg reunite at fertilization, the new resulting embryo now has a restored diploid chromosome number.
The nature of sterility in triploids now becomes apparent. During the first step of this meiosis process, the similar chromosomes (called �homologous� chromosomes) pair up in the cell just prior to division. This basic step in the meiotic process will not work accurately in a triploid cell because it is impossible for the homologous chromosomes to pair up and divide equally. The breakdown in meiotic division is responsible for the sterile nature of triploids, hence 'seedless' watermelons or oysters with firm meats during the normal reproductive months.
Production and Uses of Triploids Most triploids produced in plant agriculture are the result of crosses between tetraploid (4n) and diploid parents, the 2n and n gametes, respectively, recombining to form a triploid individual. Tetraploidy in animals is not, however, generally tolerated and other methods of producing triploids are necessary.
Clues to the viability and utility of triploids in fish came from scientists searching for the cause of individuals failing to show signs of secondary sexual characteristics in a natural population. Cytogenetic evaluation of these animals revealed that they were triploid, suggesting that this condition is tolerated and that a mechanism for triploid induction might indeed be available.
Taking advantage of earlier scientific studies with amphibians, researchers found that a variety of treatments applied to an egg shortly after fertilization often produces a triploid state in the resulting embryo. Explained briefly, this is due to the fact that, in most cases, the eggs of fish have not completed meiosis II at the time of fertilization. In a normal fertilization scenario, the egg finishes meiosis just after fertilization and the extra set of chromosomes from the egg degrades (termed the �second polar body�). By applying cold- or heat-shocks, high pressures, or certain chemical treatments this second division of meiosis is prevented and the �extra� set of maternal chromosomes is retained. The resulting embryos now have one paternal and two maternal chromosome sets and are, therefore, triploid.
Many high hopes were placed upon the first inductions of triploids, particularly in triploid trout and salmon. It was hoped that these sterile animals would grow faster and avoid the problems normally associated with sexual maturation such as loss of flesh quality and reduced product yields. In practice, however, it has been observed that male triploid salmonids undergo considerable secondary sexual development (presumably due to a large amount of normal cell division involved in the process of testis formation prior to meiosis). Additionally, many large-scale methodologies aimed at producing triploids in commercial quantities have proven highly variable in their 'success' rates (percentage of triploids actually produced).
Triploids have proven useful in a variety of other situations. Triploid fish are appropriate when the interbreeding or reproductive competition of escaped or intentionally planted fish is undesirable. Researchers have also found that inducing triploidy in hybrids between fish species that normally do not produce viable offspring somehow stabilizes the cross and increases fertilization success. These hybrid individuals have proven useful for studying many traits, including disease resistance and saltwater adaptation.
Triploid Trout and Salmon from Troutlodge Recognizing the potential benefits that their customers might derive from triploid rainbow trout, steelhead, and Atlantic salmon, Troutlodge began extensive experimentation and became one of the industry pioneers in perfecting the triploid induction process on a large scale. Early work was aimed at reducing the variation in triploid success rates, and has evolved to the state where consistent results are now achieved. Success rates, confirmed by flow cytometry (a process that measures the relative amount of DNA in a cell; triploids have 1.5 times the amount of DNA per cell as diploids), are consistently greater than 95%, with most samples demonstrating 100% induction rates. The process is now, in fact, so consistent that periodic sampling of triploid lots is utilized only as a quality control measure or upon special request.
Because of the questionable utility of male triploids in aquaculture situations, Troutlodge recommends combining the methodologies of triploidy and monosex (all-female) production. Triploid females do not produce ovaries and generally do outperform diploid fish if the intent is to rear them past the normal size or season of reproduction. Triploid, all-female stocks have proven to produce a faster growing, more uniform product in many such situations. Reports of lower tolerance of triploids to stressors in production conditions have surfaced, but are highly variable and often not substantiated with true controls.
Troutlodge managers believe that, should you need a sterile salmonid for situations involving growth past the normal period of reproduction, preventing reproduction in potential escapees, or for the production of 'trophy�-sized' animals in a recreational setting a triploid, all-female product is the fish of choice. The combination of this technology and the genetic improvement inherent in Troutlodge products makes a truly unique combination.
What are Triploids?
Ray
> Rattlesnake is a nice lake in a beautiful setting. It would be a
> good lake
> to fill with triploids, but the fluctuations in the water level may not
> allow it.
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> Bill
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