Haematological studies on a high-Antarctic fish: Bathydraco marri Norman

This paper presents the first record of the blood parameters of the Antarctic fish Bathydraco marri; the structural and functional characterization of haemoglobin purified from the blood of this species is also reported. One single haemoglobin was detected and the globin chains were purified and subsequently sequenced. The molecular weights of the α- and β-chains were 15552 and 16048, respectively. O 2 binding was measured as a function of pH and a strong Root effect as well as a large, negative, alkaline Bohr effect were observed. The subunit cooperativity was lost at lower pH values, as indicated by the decrease of the Hill coefficient. P 50 was 13.2 mm Hg at 20 °C, pH 7.5. Haematocrit, the number of erythrocytes and the haemoglobin concentration were 14.6, 0.59·10 12·1 −1 and 29.6 g·1 −1, respectively. Mean corpuscular haemoglobin concentration and mean cellular haemoglobin content were 202.7 g·1 −1 and 50.2 pg, respectively. The plasma contribution to the total O 2-carrying capacity was 16.7%. The pH was 7.7; the mean venous pressures of CO 2 and O 2 were 3.8 and 58.5 mm Hg, respectively. For comparison, a summary of the available data from other bathydraconids is also presented. Special attention is given to the mode of life and the evolution of this teleost in relation to its habitat.