Giant squids may die when exposed to warm water currents

Abstract

Strandings of the giant squid, Architeuthis monachus (Steen-strup), have always stirred attention because of the rarity and enormous size of these cephalopods. These animals have never been observed in their natural habitat and little is known about their physiology and ecology. Stranding of giant squids in Newfoundland waters has been correlated with the inflow of warm water, suggesting that increased temperature may be causing their death¹. Squids have also been carried to the Norwegian coast with the warm North Atlantic current² and on 23 August 1982 a live specimen was caught off Radöy near Bergen, Norway (Fig. 1). This catch gave an unprecedented opportunity to study the effects of temperature on the oxygen binding properties of blood from the giant squid. The present finding of an excess of a fourfold decrease in O₂ affinity when temperature is increased from 6.4 to 15°C strongly suggests that giant squids may suffocate from arterial desaturation when increased ambient temperatures are experierced.