The hematology and metabolic rate of diploid and triploid growth hormone transgenic Atlantic salmon (Salmo salar)

The goal of this research was to examine and clarify the interaction between hematology and metabolic rate for triploid and diploid growth hormone (GH) transgenic Atlantic salmon (Salmo salar). Respirometry results indicated that there were no major metabolic differences between ploidies (i.e. diploid or triploid) of the same genotype (i.e. non-transgenic or transgenic). However, at mean weights greater than ∼30 g it was clear that the metabolic rate of GH transgenic fish was significantly elevated as compared to their non-transgenic counterparts. Microscopy results indicate that triploid erythrocytes of both genotypes are significantly larger than diploid erythrocytes. As well, GH transgenic erythrocytes of both ploidies are significantly smaller than their non-transgenic counterparts. GH transgenics likely produce smaller erythrocytes in response to increased oxygen demand associated with higher active metabolic rates. Results also indicate that the mean cellular hemoglobin content of triploids is significantly greater than that of diploids, but no other major hematological differences were observed between diploids and triploids of either genotype.