It's hard to miss the latest discoveries having to do with the colossal and giant squid(s) being pulled up.  It's fascinating to think that something that large is living that far down.  And now that I'm writing this I seem to have developed another question as well:

#1 - I know pressure increases the lower you go, but I don't know by how much.  Can someone explain how the pressure system works, how far down these squid are found, and how they would deal with that?

#2 - Does any of this evidence of large squid make it more likely that there may be sharks the size of school buses roaming the deep as well?  Are whales ever pulled up with monsterous bites or anything like that?

Atmospheric pressure at sea level is roughly equivallent to water pressure at 10 m depth. For every 10 m the pressure would increase 1 atmospheric pressure (or 1 atm). So ocean surface = 1 atm, 10m depth = 2 atm, 20 m depth = 3 atm, and so on. Notice that at the first 10 m, the increase in pressure is 100%, whereas the next 10 m is only 50%. At around the depth of 2000 m where some colossal squid are reported, the pressure would be something about 200 times that on the surface.

However, change in pressure only influences gas-filled compartments but not solids or fluids. As giant squids lack gas-filled chambers, the changes in pressures should not really affect them as much.

There is a deep-sea shark called the Sleeper shark which can reach up to 6 m (or maybe even 7 m) in length. That's slightly longer than a large car but certainly one of the biggest sharks known today (except for the whale shark). In deep-sea benthic (or sea floor) communities, it has been shown that body sizes tend to be smaller than in shallower communities. This is thought to be due to the low amount of resources available at the bottom. However, body size also has an inverse relationship with biodiversity. In other words, since there are limited resources, when a benthic community is very diverse in life, then every member would be severely restricted to the amount of nutrients it can get and thus have smaller body sizes. On the other hand, low biodiversity would allow a single or a few animals to dominate resources and thus larger body sizes.

Large body size would have many advantages in harsh conditions, so it may still be possible that there are huge sharks down there that no one's seen before. Who knows?

As for your last question, there are many known examples of scars on the skins of sperm whales that were most likely made by the suction cups of the giant squid. Some of the scars would suggest even bigger giant squids, but these scars could have been stretched and exaggerated over the lifetime of the whale.

Last edited by Manabu Sakamoto (5th Mar 2007 12:11:30)