Neutrophils of diploid and triploid rainbow trouts assessed by flow cytometry

Triploid rainbow trouts Oncorhynchus mykissare reared in Brazil, but there is no data about haematological differences when compared to diploid ones. Due to the lack of information, the goal was to evaluate the neutrophils of adult diploid and triploid rainbow trouts O. mykissby flow cytometry screening using a monoclonal anti-neutrophil antibody (TTL-5E9). In comparison, the population of neutrophils was proportionally larger in diploid trouts (9.94 ± 4.64% vs. 5.58 ± 1.09, p = 0.0481), but with cells showing smaller size and less complexity thanthe neutrophils of triploid trouts. Assorted neutrophils were not evaluated on phagocytic activity or apoptosis induction, it was not possible to establish neutrophil activity differences between ploidies.