Blood pressure in the squid, Loligo pealei

Abstract

1. 1. Blood pressure and heart rates were measured in unrestrained Loligo pealei. 2. 2. At minimal activity levels systolic and diastolic pressures in the anterior aorta were 7.18 and 2.72 kPa respectively and heart rates were 102 beats per minute. 3. 3. Peak and low pressures in the afferent branchial vessel were 0.92 and 0.04 kPa while mean pressures in the anterior vena cava and efferent branchial vessel were 0.32 and 0.18 kPa. 4. 4. These blood pressures at rest are the highest reported to date for any cephalopod and are probably indicative of the active pelagic existence of these squid.