AQWA: Squid perfectly at home in abyss

Rams horn shell washed up at Mettams.
Rams horn shell washed up at Mettams.

AQWA operations manager Sasha Thompson writes this week of evidence of the abyss.

TWO kilometres may not seem like much of a daily commute but add in a deep sea trench, squid and geometric design and you’ve got me intrigued!

Known as ram’s horn shells, these spirals stick out of a small squid’s body and each little chamber is precisely grown so that it is larger but proportional to the one before.

This sort of spiral is called a logarithmic spiral and is found in hurricanes, spiral galaxies and the path of a moth towards light.

For the squid this shape means its balance will be maintained as it grows and it won’t need to keep relearning how to swim – handy when you travel 2000m up and down the water column every day to feed.

Where around here is there water that deep?

Off the back of Rottnest Island is a deep sea trench known as the Perth Canyon.

Carved by the flow of the Swan River during the last ice age, the Perth Canyon is Australia’s largest underwater feature.

It slices west through the continental shelf for 200km, reaching the ocean abyss at a depth of over 4000km.

In water this deep and dark scientists listen, rather than look, for marine life.