Non-nucleated erythrocytes in a teleostean fish Maurolicus Mülleri (Gmelin)
They have no nuclei. Whether nucleated erythrocytes exist in the blood could not be stated with certainty. Nucleated cells make up less than 1 % of the blood corpuscles and do not show the staining properties of mature erythrocytes.
They are exceptionally small, 4–6 × 2–3 μ. So small erythrocytes are found only in a few mammals.
They do not seem to be flattened. It is suggested that this is correlated with their small size.
It is pointed out, that prevalence of non-nucleated erythrocytes in the blood must be very rare in teleostean fishes, since a great number of species have been investigated and were found to have nucleated erythrocytes. The only example of a non-mammalian vertebrate with predominantly non-nucleated erythrocytes in the blood was previously the urodelan genus Batrachoseps. In some respects the blood of Maurolicus is more mammal-like than that of Batrachoseps.