Comments on: Why are there no fish in the deepest deep sea?

By: Matt Bille

Matt Bille — Fri, 18 Sep 2015 19:04:48 +0000

I understand the basics of the biology and physics here, but I’d hesitate before determining the deep to be “fish-free.” Evolution is, in action if not in intent, unbelievably clever about fine-tuning life to exist where it should not. Ask the folks who put tardigrades on the OUTSIDE of the International Space Station and recovered them alive.

By: HenryC

HenryC — Mon, 14 Sep 2015 14:29:13 +0000

The deepest ocean is also very cold. Fish fight cold with glycol, which could become very toxic under the pressures we are talking about. Just a thought,

By: Ethan Hulbert

Ethan Hulbert — Thu, 10 Sep 2015 18:57:37 +0000

So fascinating here. Do you happen to know of any other educational resources related to these extreme-deep-sea environments? Fish or not, whatever is down there is so interesting.

These hadal amphipods – what do they eat? What does whatever they eat, eat? How low can they go before the pressure is too much for them?

I wonder if there is ever a point where the nature of DNA starts to change to resist pressure better. Perhaps there are mutations with stronger or bigger clusters of proteins that are more resistant to pressure. It could probably tell us a lot of useful things, too, as I think many extremophiles can, but really it’s just fascinating in its own right.

By: Lierman

Lierman — Wed, 09 Sep 2015 18:38:39 +0000

Too bad for the Ancelade sub-ice ocean… won’t find many salmon there… nor moon fish surprinsingly

By: Denis

Denis — Tue, 08 Sep 2015 19:23:19 +0000

In reply to brz.

I am no fish evolution specialist.

But I am not sure we can assess with confidence that fishes have a trend to live deeper. Preservation of fossil fishes requires good conditions that do not occur everywhere.

And, I don’t think that very deep water fauna are that frequent.

Also, yes, it is possible that fishes will evolve to live deeper, but in general evolution is difficult to predict and subject to contingency… For instance, after over 500 MA, echinoderms are still stubbornly restricted to salt waters.

By: brz

brz — Tue, 08 Sep 2015 16:57:16 +0000

In reply to brz. ^ "working their way down", that is.

By: brz

brz — Tue, 08 Sep 2015 16:56:25 +0000

is it possible that some type of fish will eventually get below the 8400m line, but those fish haven’t evolved yet? i don’t know if this is true, but i would think that fish evolved at initially a shallower depths and have been “working their down” ever since.

By: SN Currie

SN Currie — Fri, 04 Sep 2015 17:09:25 +0000

Fascinating fish… It’s basically a swimming head/stomach with attached fins for locomotion. Just enough tunk & tail to hold the spinal cord and minimal musculature to generate undulatory waves.

By: Tony

Tony — Fri, 04 Sep 2015 15:47:09 +0000

In reply to Denis.

A bit like a reverse treeline:
http://www.nature.com/scitable/content/ne0000/ne0000/ne0000/ne0000/15899424/f2_berdanier.jpg

At some point the conditions are absolutely no longer suitable but there is a gradient along the way.

By: RR Helm

RR Helm — Fri, 04 Sep 2015 04:49:07 +0000

In reply to Jon Norenburg.

“I figured certain membrane lipids can act as transducers to provide pressure information.” Wow, I’ve never heard of anything like that, but I’m really digging the idea. If fundamental features of an organism’s biology changes with pressure, having a way to sense and interpret subtle pressure changes could be pretty useful. Specialized organs? Cells? Organelles? Molecules? Wow…that’s really interesting…