Why triploid trout

Triploid fish have three sets of chromosomes instead of two sets. Female fry, which have an XX chromosome complement, are changed into morphological males by feeding them male hormones. We refer to these sex-reversed fish as XX males.

Even though these fish are genetically female they produce sperm instead of eggs. When sperm from an XX male is used to fertilize eggs, the offspring are all female.

After they are sacrificed for their sperm, these fish are discarded — they are never stocked. Here the testes from XX males are being crushed to release sperm so they can fertilize the eggs. Eggs are gently squeezed from a female rainbow trout. In North Idaho, I am happy to fish trout; better triploids than nothing. That being said, I am extremely disappointed to see triploid trout being planted in isolated waters. Why plant fish there that will not reproduce and give us a viable population?

Job security? I enjoy eating fish, but placing sterile fish in all waters; even waters where they are not beneficial, is disappointing. Part of the outdoor life, is a degree of independence and self-sustaining behavior.

There is nothing wild or self-sustaining in a triploid population. Thanks for reading, Bob. I was simply highlighting a few of the ways biologists use triploids. In a situation where a sterile predator is needed to control an invasive species, for instance, I can really see the benefit. My experience with rainbow tripliids has been tremendously satisfying.

We call them footballs here in Washington State because they are so fat! Where do the fertilised eggs for the triploid manipulation come from? Will we be in danger of losing the trout species due to most trout being infertile and the fertile stock being wiped out by an infection. Over millions of years evolution resulted in healthy lake catchment areas ,that with the help of hatcheries, resulted in a sustainable population with excellent sport for anglers.

A biologist would be a better resource. By using this form you agree with the storage and handling of your data by this website.

Sign up for the mailing list and get my free Backcountry Fly Fishing Gear Checklist delivered to your inbox! This is a list I made and use for my own trips, and I think any backcountry angler will find it handy!

Skip to content. What is a Triploid Trout? Katie Burgert February 10, 11 Comments. In appearance, triploid trout are pretty much identical to diploids. Once hatched, diploid and triploid trout can be raised the same way. Katie Burgert 25 Aug Reply. Asta Stephansen 29 Jun Reply. The production of AF3n fish for stocking derives the benefits of both the process of "feminization" and triploidization AF and 3n.

Fisheries managers can improve small lake fisheries by matching specific lake characteristics with the appropriate strain and stock selection, stocking rates and regulations.

Fish size at stocking is another consideration to improve fish performance. The size a fish can be reared to in a hatchery facility is limited to some extent by tank space and other economic constraints. However, there may be some situations that warrant size consideration:.

We use cookies to optimize website performance and for advertising purposes. If you continue to use our site, we assume you consent to the use of such cookies.

For more details and to learn how you can manage your cookie preferences please see our Privacy Policy. Buy a fishing Licence. Triploid 3n fish This technology involves a sterilization process that is unique to each species of fish. It reduces the risk of genetic interactions between hatchery and wild fish.

It prevents the establishment of hatchery-origin populations in areas of conservation or biodiversity concerns.

All-Female AF fish The development and maintenance of all-female broodstock occurs in a captive environment. A female has two identical chromosomes which are called the X chromosomes; female with two X chromosomes are said to be XX.

In a male, the two sex chromosomes are not identical, one being much smaller than the other. The small chromosome is called the Y chromosome so a male is XY. Only males have a Y chromosome, but they also have a single X chromosome. When an egg or a sperm is made, one chromosome of each pair goes into the egg or sperm so that the egg or sperm has only 30 chromosomes, not 30 pairs of chromosomes. One or other of the sex chromosomes goes into each egg or sperm.

The egg comes from the female whose cells always have two XX chromosomes and no Y chromosome. Therefore all her eggs contain one X chromosome. The male has one X chromosome and one Y chromosome and therefore half the sperm cells have an X chromosome and half have a Y chromosome. A baby starts life when a single sperm fuses with a single egg and restores the chromosome number to 30 pairs of chromosomes. The sex of the baby they produce is therefore dependent on the sperm; if the one sperm that fertilises the egg carries an X chromosome the baby will be female; if it carries a Y chromosome the baby will be a male.

The Y chromosome is tiny in humans anyway and is about the size of one of the number 29 chromosomes in the picture. The merging of the 30 single chromosomes into 30 pairs of chromosomes in the first cell of the baby trout is the starting point for making that individual trout. The trout grows by that one cell dividing and becoming two cells, and then dividing again to make 4, and the 4 then dividing to make 8 and so on.

These divisions are not like the ones I described above which only occur in the testes and ovaries. In all other cells divisions, instead of one of each pair going into the sperm or egg, an exact copy of every chromosome is made and the copied chromosomes go into the new cell. Therefore every cell in the body, except for the eggs and sperm, has identical chromosomes and therefore genetic information.

Below is a picture of human chromosomes, each of which has made an exact copy of itself, with the two copies still joined together. When the cell divides these two identical strands of each cell are pulled apart with one part going into one of the new cells and the other part going into the other new cell. The red bits are the skin of the cell, the green bits are the traction engines pulling the chromosomes apart and the blue bits are the pairs of chromosomes being drawn apart.

Normal cells are diploid, meaning a pair of each of the 30 chromosomes, as shown in the first picture. Triploid means having a triplet of each of the 30 chromosomes.