Growing up the Trophy Triploid Trout

Ted’s Trophy Triploid Trout

TT trout splash

What is a Triploid Trout?

A triploid trout is a trout that is sterilized, due to having three sets of chromosomes instead of two sets. This happens when, upon fertilization of the egg, the sperm brings with it one set of chromosomes and combines them with the two sets already in the egg — making three sets of chromosomes. Normally, in the natural world, just after fertilization, one set of chromosomes is thrown off, leaving two sets. Although this is common, it doesn’t always happen, which is why we sometimes find triploids in natural fish populations.

It was this discovery that led aquaculturists to the realization that a trout with three sets of chromosomes was, in fact, sterile. After this discovery, a method was found which involved ‘shocking’ the eggs with heat or pressure upon fertilization, a process which prevented the third set of chromosomes from being thrown off, thereby producing an entire population of sterile, triploid trout.

“We’ve been using Ted’s Trout for years to stock our lakes. These trout are amazing! The healthiest, strongest and most adaptable fish we know. We stock these trout in many different lakes throughout the ranch with different types of water conditions and they all thrive. Our guests can attest to the fight they give when fishing them!
Ted is great to deal with too. He is always available to answer any questions we may have and offer insight.”

— Yuki Sageishi, Recreation Manager, Douglas Lake Ranch

Why a Triploid Trout — do they grow faster and bigger?

It has been thought that if a sterile trout could be produced, we would have a fish that would grow faster and bigger, and be more efficient with their feed. This could be true or not (depending on your experience), however, there are pros and cons to growing sterile fish.

A con is that triploids are somewhat less resilient than natural (diploid) trout when water quality conditions deteriorate, ie. warmer water in the summer and colder water in the winter — both of which can cause lower oxygen levels in the water, which causes greater stress in triploid trout.

Generally our experience is that triploid trout are a little slower growing. However, since they do not go through a spawning cycle, theoretically, they will continue to grow all year long and make up for the slower growth by putting energy into body weight, rather than the reproduction process.

In any population of trout, you will naturally have fish that grow faster and bigger than others; a population of triploid trout seems to be no different.

The biggest ‘pro’ with sterile fish, is when you have a pond with no facility for spawning, the fish will not go through the spawning phase and become egg-bound — which can stress a fish for a short period of time.