Reduced growth may be linked to lower aerobic scope in juvenile triploid white sturgeon ( Acipenser transmontanus )

Previous studies have provided evidence of a reduced aerobic metabolic capacity, both at the cellular (metabolic enzyme activity) and the whole organism (aerobic scope) level in juvenile triploid white sturgeon, compared to diploid siblings. The downstream costs of this reduced metabolic capacity are still unclear, yet a lower aerobic scope suggests triploid white sturgeon likely have less energy to allocate to biological processes like growth and development. We conducted a 15-week growth trial to assess energy allocation to somatic growth in 2-month-old diploid and triploid white sturgeon. Spontaneous swimming activity, hepatosomatic index, condition factor, and deformities were also measured throughout the growth trial as indices of energy allocation to activity and fish condition. In general, our results indicate that triploid white sturgeon may have less energy available for processes beyond basal maintenance. This could be linked to a reduced overall performance as evidenced by lower weights and more deformities when compared with their diploid counterparts. However, many indices were still mostly unaffected by triploidy (condition factor, hepatosomatic index, and swimming activity). Whether this lower growth performance seen in juvenile triploid white sturgeon continues through sub-adulthood, puberty and final maturation requires further long-term studies.

Automated summary

The study found that juvenile triploid white sturgeon have a reduced aerobic metabolic capacity compared to diploid siblings, which may affect their growth and overall performance by limiting available energy. Despite lower weight and more deformities, other indices such as condition factor, hepatosomatic index, and swimming activity were mostly unaffected by triploidy. Further long-term studies are needed to determine if this lower growth performance in juvenile triploid white sturgeon persists through sub-adult, puberty, and final maturation stages.