Many of you may remember back five years ago reading about fishermen from New Zealand who accidentally caught and carefully hauled aboard their boat a 1,000 lb, 33ft, colossal squid (Mesonychoteuthis hamiltoni). It was frozen until researchers could devote time to studying it.
Those studies have begun. This National Geographic Daily News story, based on a study published yesterday in Current Biology, offers an explanation as to why colossal squid and giant squid (Architeuthis dux) have such enormous eyes. These are animals who live in deep, dark marine environments, where the only semblance of light comes from bioluminescence.
These large cephalopods are of interest to us because they are a known prey item of sperm whales, the largest toothed predator on the planet. The authors of the study have proposed that these two species of squid are able to use their oversized eyes to detect the minute bursts of light given off when sperm whales swim through the tiny deep sea organisms that can create this light. This gives them an opportunity to react and avoid sperm whales that have used their echolocation to find the squid.