Very large rainbow trout above 5 kg up to 8 kg is a highly valued product in several markets. Genetics, local temperature profile and environmental conditions in general does however not always allow production of this size fish in time to avoid the risk of maturation. The solution is triploidization of the chromosomes, efficiently sterilising the fish and eliminating the risk of maturation.
Triploid fish will continue to grow throughout their lifecycle without the setback of maturation allowing farmers to produce (almost) any size desired.
Despite the obvious advantage of triploids in relation to, these products do also come with considerations.
- Triploidization alters the shape of the red blood cells and the affinity of these to oxygen, meaning that the fish will be more vulnerable to fluctuations in oxygen and low oxygen saturation in general. Hence triploids should only be produced under optimal conditions, where a certain minimum oxygen saturation can be guarantied at all times.
- Somewhat linked to the above, triploid fish tend to be more sensitive to handling and stress full conditions, heart failure and sudden mortality is often seen in relation to handling and other stressors.
- Although AquaSearch only uses high pressure technology (the more gentle method), deformity frequency will be higher, than what is seen in conventional diploid fish. Spinal deformities may occasionally be correlated with uneven fillet pigmentation. Individual batches may be affected in up 5 – 10 % of the fish.
Genetic background and breeding
AquaSearch …. TRIP is offered from most AquaSearch breeding lines and can be supplied as an additional feature to other desired traits and qualities.
General breeding traits and qualities
- Pending the specific breeding line
- No risk of maturation. tiny percentage of unintentional diploid fish (< 5%) may eventually mature.
- The ploidy of all batches are tested prior dispatch. A 95% cut off value are observed.
- Customers receive a copy of the batch specific ploidy test.
- Minimum 10 % surplus to, compensate variations in hatching rate.
Optional breeding traits
- Additional reduced risk of second winter maturation (marker assisted selection)
- Additional improved RTFS resistance (marker assisted selection)
- Additional improved vibriosis resistance (marker assisted selection)
- Improved white spot disease resistance (marker assisted selection)
AquaSearch breeding lines are all rounded by more than 40 years of domestication and selection for growth and appearance, when this is combined with modern “state of the art” breeding techniques, and all triploid products can be characterized by the following:
- Specific disease-free origin
- High hatchability (> 90% guarantied*)
- *Pending recognized hatching conditions
- Guarantied all female triploid material (95%)
- General high stress and disease tolerance.
- High growth rate
- Low feed conversion rate
- Elongated body shape.
- Potential high feeding rate