87 votes
Accepted

Why would an underwater creature remain lodged to its prey?

To be annoyingly clingy Your super lobsters seems to have the ability to hunt anything. The barbs makes it easier for a team of them to hunt prey much larger than themselves. The main purpose of ...
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63 votes
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Let's weaponize jellyfish

Would you be interested to know that annually, Jellyfish kill more than ten times as many people as sharks do? Not bad for a creature that is 95% water and doesn't have a brain! That being said, ...
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  • 1,689
60 votes

An underwater creature that could take down a boat

Give that Columbus' craft were built using Carvel construction (butt jointed wood caulked with tarred hemp that is hammered into the joints and then a coat of tar over everything beneath the waterline)...
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54 votes
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A fast aquatic predator with multiple eyes and pupils. Would these eyes be possible?

This is the four-eyed fish: It has only two eyes, but it has two pupils and two retinas in each eye. It evolved to hunt by the water surface, catching prey from both above and below. Where there is ...
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48 votes

Why would an underwater creature remain lodged to its prey?

Because you are a sprinter only (in contrast to your prey) Some animals such as cheetahs are not capable of hunting a prey such as a gazelle for more than a few hundred metres. The gazelle is capable ...
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47 votes
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Could a jellyfish be bio-engineered to convert salt water into fresh water?

No. Jellyfish are osmoconformers Osmoconformers are marine organisms that maintain an internal environment that is osmotic to their external environment.[1] This means that the osmotic ...
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  • 277k
45 votes
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What if the ocean's salt level decreased by 50%?

Phase 1: The Extinction Most life in the sea would die out almost immediately. Saltwater fish, invertebrates, and most importantly plants and microbes are finely-tuned for a particular level of ...
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  • 28.3k
45 votes
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Living biological boats? (Jasconius)

That's where its food source is. Most algae is found near the surface of the ocean, so if this creature has a semi long neck, it can swim gently along moving its head back and forth, up and down ...
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  • 7,181
43 votes
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Would the existence of Megalodon during the medieval ages threaten Sea Travel and how to defend against them?

No Megaladon is not fundamentally a more fearsome or ferocious beast than a sperm whale, which is also carnivorous, of similar size, probably smarter, and has as documented capability to sink 240 ton ...
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  • 84.3k
42 votes

Let's weaponize jellyfish

Now kids, don't try any of what you are about to read at home. You do not want to mess with the Geneva Convention. I am going to answer both, how you can weaponize jellyfish (sea jellies, to be ...
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  • 5,568
40 votes

How would a ship defend against a sea creature, and possibly win?

Rolling attack - Have a heavy keel I just wrote a big post about naval architecture principles, much of which applies here as well. To minimize the chance your ship rolls, attach a heavy keep to the ...
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  • 84.3k
39 votes

Would oceans filled with long-lived, omnivore, intelligent Krakens make sea travel impossible?

Octopi play. source The ocean can be terrifying. More terrifying is being played with by an intelligent predator. It grabs a person then leaves. It hits the boat and then leaves. It throws a huge ...
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  • 277k
36 votes

Why would a species that had never been exposed to light react to light?

Because it can still feel temperature differences. Light is energy. Depositing energy on the skin (or deeper in the body, if the skin is transparent, as it often is for deep sea creatures that live in ...
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34 votes

Would evolution select for mermaids without breasts?

A walrus A hippo Both of them can swim much faster than a human being, despite the clumsy looking proportions and giant weights. Next are the winners of different length swimming contests in Dubai ...
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  • 20.4k
30 votes

Living biological boats? (Jasconius)

Needs sunlight It could have a usage for sunlight. Maybe a system similar to how plants use sunlight in photosynthesis. Heck, it could be exactly that. Make it have cells with photosynthetic ...
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  • 883
29 votes

Why would an underwater creature remain lodged to its prey?

They feed through their horn There are animals that already do this, the most famous of which are leeches, ticks and lampreys. They attack their prey, latch on, feed, then let go once they're either ...
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  • 8,319
26 votes
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How long could a Kraken's carcass survive if preserved in salt?

I'm going to assume that when you say "Kraken" you mean "giant octopus monster" meaning something biochemically identical to a modern octopus but huge. I'm also assuming that the water stays gone and ...
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  • 44.4k
26 votes

Hammering under water?

That would be not a hammer, but an axe. Stone age hammers and axes did not differ much, and in most cases were both - depending on the side you used (this is still the case for "civil" axes). An axe ...
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  • 9,875
25 votes

An underwater creature that could take down a boat

This is not as straight-forward as it sounds. Some problems as I see them: 1. Oceanic Exploration Not a New Thing At the time that Columbus "discovered" the New World, the Vikings had already ...
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  • 34.5k
22 votes

An underwater creature that could take down a boat

The most realistic way—historically correct, even—seems to be a case of the overly hungry naval shipworm (Teredo navalis var. esuriens). Columbus had a large problem with them, the ...
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22 votes

Would oceans filled with long-lived, omnivore, intelligent Krakens make sea travel impossible?

I am not sure that those kraken would consider human ships interesting prey. After all most of the ship is inedible (wood) and hunting those little, pesky critters hugging to the "huge log" ...
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  • 2,211
21 votes
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An underwater creature that could take down a boat

Mega-AquaBoa-Constrictor The problem I have with animals biting the ship is that one bite would likely deter them. It seems like a lot of sea animals like sharks usually take one bite of something ...
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  • 17.3k
19 votes
Accepted

What underwater creature would be well-suited as a pack animal?

You're going to want to obtain some whales. Not only are they the largest mammals alive, they also have the largest muscles. Whales travel in pods, the equivalent of a "pack" of wolves. They're ...
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  • 18.8k
19 votes

Sonar Jamming Squids

A cloud of smaller host creatures scatters the sonar. The squid is followed by a cloud of small creatures that scavenge the scraps of the squid's food. In return they serve to scatter the sonar waves ...
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  • 41.9k
18 votes

Would evolution select for mermaids without breasts?

Evolution would select for human style breasts ...given a few things are true. First, humans have effectively removed predatory pressure as a cause for human evolution, and with sapience I would say ...
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  • 32.5k
18 votes

What if the ocean's salt level decreased by 50%?

Life would not be able to evolve in this short amount of time. Organisms able to survive the lower salt concentrations (of which there would be some in the ocean) would survive, organisms not able to ...
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  • 4,553
18 votes

How would a ship defend against a sea creature, and possibly win?

If your kraken is basically like a giant squid, we can take a two-pronged approach to defend against all of your attack methods. First we want to prevent the kraken from grabbing hold of your ship to ...
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  • 3,022
17 votes
Accepted

Could a mature (and giant) lobster remain in sea water indefinitely without decaying?

What would she look like after a few hundred years of submersion? Like a really big lobster. Regular lobsters live in the sea, and can live to over 100 years old and still look just like lobsters. ...
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16 votes

Living biological boats? (Jasconius)

Buoyancy is a big deal for sea creatures. Pretty much everything living on or in water have a density that makes them naturally comfortable (i.e. energy efficient) only at certain depths, and changing ...
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16 votes

Under what circumstances would a nuclear war render Earth's oceans uninhabitable?

Not possible. You land dwellers need the ocean to survive. Don't forget that the oceans are part of the water cycle. If they are so messed up from radiation that no life can thrive in them, then the ...
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