(SERIOLA QUINQUERADIATA), AND A COMPARISON WITH

The blood of a carangid fish, the yellowtail (Seriola quinqueradiata) has been studied with particular reference to the deformability properties of the red blood cells. The rate at which blood flows through a Nuclepore filter containing 5 /im pores has been determined under the same conditions that have been used with human blood. Marked differences were found in the flow of yellowtail blood which depended on the particular way in which the blood had been sampled. Such differences seem to be due to a sensitivity of fish red blood cells to their environmental conditions. Blood flow through filters is temperature-dependent, the rate increasing with a rise in tempera-ture. Measurements made at 37 °C gave values which were similar to those normally obtained for human red blood cells, in spite of their greater dimensions (10-4 x 6-8 x 3-4 /im), and nucleated nature. It was also found that the blood flow rate of human blood was slower than that of yellowtail blood when measured at the normal environmental temperatures (15 °C) for these fish