Horrible Deep Sea Thread

Hi again!

It's been about two months since the last time, so I figure I can make another horrible deep sea thread at this point (I keep making these a week or so before end of term exams, because that's both when I don't have much homework left and need to do something to justify to myself why I'm not reading about continuum mechanics right now). Last one was pretty fun, I think.

If you know the drill, you also know I mostly repeat the same facts (I try to collect some new pictured between every thread though).
If not, how it goes is that I post pictures and facts about creepy deep sea creatures, and hopefully people will talk about how they could use it as inspiration in games (which usually at some point ends up devolving into talk about creepy deep sea waifus).

Anyway, to get the basic facts out of the way, the ocean is really deep. Like, a lot deeper than people generally think. The average depths of oceans is over 4 kilometers, and it can be far deeper. If you levelled Earth's surface by taking all the landmass from the continents and using it to fill the oceans, the planet would still be covered by a layer of water 2 kilometers deep.
Out of that huge water column, only the top 200m (650ft) has enough light to allow photosynthesis. Beyond that everything is in permanent twilight, until at about 1km all light has been absorbed by water and everything is shrouded in eternal darkness.
The deep sea is the largest biome on the planet by a huge margin, as it makes up over 90% of the oceans, which in turn cover over 70% of Earth. It is also a very hostile environment. In fact, for the longest time it was assumed that nothing beyond bacteria, and maybe some very hardy invertebrates, lived there. After all, what could possibly survive down there, in eternal cold and darkness, with pressure of thousands of tons per square meter? As is typical, man had once again underestimated just how resilient and adaptive life actually is...

Other urls found in this thread:

suptg.thisisnotatrueending.com/archive/50063651/
suptg.thisisnotatrueending.com/archive/49846384/
quietplease.org/index.php?section=episode&id=60
twitter.com/NSFWRedditVideo

“Because the history of evolution is that life escapes all barriers. Life breaks free. Life expands to new territories. Painfully, perhaps even dangerously. But life finds a way.”
...Did I mention I really like Jurassic Park? Maybe I should branchinate and do a Terribe Dinosaur Thread at some point...

But I digress. The point is, that life not only survives, but thrives, in the deep sea. For a given value of thrives. It is certainly an extreme environment, and animals living there have had to develop all sorts of special adaptions just to survive. Many of which also result in bizarre and outlandish, often outright nightmarish, appearances.

First, there's the pressure. This is actually pretty easy. Water creates a pressure field that is the same at every direction. A hollow object, like a submarine, will have comrpessive force applied to its surface from all sides and implode unless its is extremely sturdy (bathyspheres and such have several inch thick steel walls). If, however, you body is of similar sensity and composition to water, there is no difference between internal and extrernal pressure and the pressure field passes through you undisturbed. So most deep sea creatures has watery, gelatinous flesh.

The bigger problem is lack of, well, anything. There's no plants so, aside from a few spots in the ocean floor where there's hydrothermal vents that allow chemothropic life, the entire ecosystem is reliant on scraps falling down from the surface waters. The oxygen content is also lower than on surface.
To save energy, pretty much everything unnecessary has to go! Streamlining is the way forward! Reduce size, reduce the amount of energy-intensive muscles, get rid of all the fancy stuff that uses energy and you don't absolutely need to survive!
But you can't really make a zero-energy fish, so your fish still needs to eat something. And because the deep sea is so huge and empty, finding something to eat is hard.

There's no point in making these threads if you just mindlessly reiterate yourself over and over again.

Either talk about different creatures then last time, such as isopods or squids, or discuss different topics to last time.

This isn't meant to be an insult or anything but I don't see the point in you just repeating yourself.

...And now we get to the whole "deep sea horrorfish" territory, and why we also call the deep sea "underwater vore hell" (at least here on Veeky Forums; I'm not the one who coined the term, but I find it appropriate). Because food is so rare, the deep sea foodchain is less of a chain and more of a...I don't know, a weird tangled mess. On the surface you got phytoplankton (microscopic algae) that produece energy from photosynthesis, small invertebrates that eat the algea, small fish that eat them, bigger fish that eat the small fish, and even bigger fish that eat those fish. In the deep sea, you got the same basic setup, except you replace plankton with marine snow (biomatter falling from surface waters; basically fish poop and dead organisms). But then instead of having a sensible progression of a food chain, you've got big fish eating small fish and small fish eating big fish and generally everything trying to eat everything else (there are some fish with more normal feeding habits there as well, like the ones in the OP. No wonder they looks so horrifed).

In order to maximize their chance of finding food, many deep sea fish have huge gaping maws with enormous needle-like teeth, and elastic sack-like stomachs that can expand to hold prey larger than themselves. When you're unlikely to encounter another potential prey for a month, you can't afford to pass the opportunity over a trivial thing like said "prey" being twice your size and also trying to eat you.

In order to save energy, msot deep sea fish are ambush predators. Their skin is often pitch black or blood red blend in with their surroundings (red light is the fist to be absorbed by water, so most deep sea animals can't even see red light), and they have light-producing organs called photophores that are used both for camoflauge (closer to surface where some weak light still trickles down, they are used to break the fish's outline when viewed from below) and for attracting prey.

This. If you want a blog, go write one instead of copying yourself.

>The point is, that life not only survives, but thrives, in the deep sea. For a given value of thrives.

Yeah, in this case "thrives" is somewhere around "look long and hard enough and you'll eventually find something". There just isn't enough energy to go around down there for anything more, apart from the fumaroles (a few rare, tiny dots in the immense abyssal landscape) you're literally dependent on the scraps sinking down from above, and the open ocean doesn't have much of a density of life to begin with.

So no, the only way to describe it as thriving is to rob the word of all meaning just so you can pretend the (very damp) desert is a rainforest.

That's why I try to do it rarely enough to have some new audience every time, and post new pictures. But yeas, lat time I didn't talk about giants squid at all. Which is a mistake that must be corrected.

Giants squids (and colossal squid, which are broadly similar but even giant-er) are a prime example of deep sea gigantism. While deep sea fish are usually very small, there are many invertebrates that grow far larger in the deep sea than in the surface. Probably because on the surface they wouldn't be able to compete with large fish. The length of a giant squid from tip of the mantle to the tip of the long tentacles is estimated to be at maximum 13 meters. Colossal squid is slightly larger at 14m, and also notably more massive.

Very little is know for the giant squid, as for a long time they were only known from dead animals washed up on the shore, or remains found inside the stomachs of sperm whales, their main natural predators. In fact, the fist picture of a live individual in its natural habitat was taken in early 2000s.
They appear to live all over the world's oceans, at depths of up to 1km, and feed on fish and squid (including smaller individuals of their own kind). When fully grown, their only natural enemies are large predators such as some deep sea sharks and, most famously, the sperm whale. Colossal squid make up the majority of a sperm whale's diet, and hides of the whales are covered with distinctive scars created by the squids' suckers (as an aide, colossal squid have no only suckers, but also sharp hooks inside said suckers). The appear to mature quite rapidly, although details of their lifecycle are largely unknown.

Random fact of the day: the giant squid has the largest eyes of any animal alive (some species of ichthyosaurs are the only known animals to have lived that had even larger eyes), which are almost a foot across.

You're making it a routine now but hey, at least you're trying to vary things up.

It's still considerably more than was originally thought. There's a very large variety of creatures living down there, certainly more than just the bacteria originally thought. Though for obvious reasons the density of life is very low, animals have adapted to survive there just fine (and due to the sheer size of the deep sea, the total biomass there is actually enormous; the bimass of lanternfish alone outweights that of all commercially caught fish put together).

Anyway, a giant squid. They're pretty hard to preserve, due to being mostly soft tissue (the beak, and the tentacle hooks in the colossal squid, are the only hard parts). They maintain neutral buoyancy by having lots of ammonia in their tissue, which also makes their flesh smell and taste pretty terrible.

One very interesting thing that can be found in some areas of the ocean floor, primarily around the mid-ocean ridges but also in other volcanic hotspots, are hydrothermal vents (aka. black and white smokers). They're areas where water penetrates into the oceanic crust, where it's warmed by geothermal heat, dissolving minerals that are then precipitated as the water rises back up and coold down. Black and white smokers have different mineral composition (black ones have more sulfided, white ones silica).
The reason why they're interesting is that they are the basis of an ecosystem unreliant on sunlight. Instead, you have bacteria that obtain energy from hydrigen sulphide, which form the basis of the ecosystem. Some animals eat the bacteria directly while others, like the famous giant tubeworms, have symbiotic relationship with chemothrophic bacteria living in their bodies. The tuberworkm has no digestive system at all, but its body is full of bacteria that produce sugar in exchange for suphates.
As a random curiotisty, there has been found a photosynthetic bacteria living in the hydrothermal vents as well. Apparently it obtains energy from the (very dim) glow of the vents. Seems pretty ineffient to me, but life often does weird things.

As an aside, the material precipittaed by black smokers is rich in suphide ores, particularly copper and magnesium, but also gold and silver. In fact, there are several well-known ore deposits that are formed from ancient hydrothermal fields that got wedged up onto continental crust during subduction.