Questions tagged [sea-creatures]

For questions involving creatures in seas/oceans. This tag is useful when paired with a broader creature tag such as "biology," "creature-design," or "xenobiology" in order to provide the most specific information possible.

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67
votes
11answers
11k views

Let's weaponize jellyfish

Jellyfish are... weird. They're clear, slimy, and can sting after death. Sounds perfect for experimentation, so lets weaponize them! Consider a hypothetical world where jellyfish are extremely common ...
49
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13answers
7k views

Why would an underwater creature remain lodged to its prey?

Enter the [Insert cool and awesome Latin name here] - this species is 3 times the size of a lobster from front to tail, and a powerful hunter. Operating in swarms, they are my worlds equivalent of the ...
38
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18answers
11k views

An underwater creature that could take down a boat

Imagine that when Christopher Columbus sailed West in his Carrack to travel around the world to reach India, he had never made it to land, because halfway across the Atlantic Ocean between Europe and ...
35
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24answers
6k views

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

Let's say the oceans' apex predator on a planet similar to Earth is a species of Kraken (octopus, just big huge ones) that live 200 years in average (so they have plenty of time to develop their ...
33
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18answers
5k views

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

I have a Viking-inspired race living on a harsh ocean based planet with very rough and cold seas. In these seas there are giant creatures, not unlike kraken who frequently attack ships. I was thinking ...
30
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10answers
3k views

Living biological boats? (Jasconius)

There's this creature that swims over the surface of water and it's giant, almost the size of a whale and has thick scales as armor over its back. This creature almost never dives underwater so from ...
27
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8answers
9k views

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

What would happen to the fish/animals living in the ocean, if the water became 50% less salty, within the space of three months? Would everything die, or would they evolve very quickly? Related: What ...
27
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5answers
4k views

A fast aquatic predator with multiple eyes and pupils. Would these eyes be possible?

I’m currently in the works of an alien design, one which lives in the ocean most of its life and occasionally surfaces in shallow waters to mate. It has 4 eyes, with each side of the head having a ...
20
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5answers
1k views

Sonar Jamming Squids

Context In the arms race of survival many animals have developed ways of evading predators, but the animal I am interested in for this question would be the tiger moth. So basically these guys jam bat ...
19
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9answers
8k views

Could a jellyfish be bio-engineered to convert salt water into fresh water?

For my future world, I've decided that coastal cities need fresh water and there isn't enough of it to go around. I don't know how jellyfish work. Is it feasible or completely impossible for ...
18
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9answers
3k views

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

Suppose that there was a tribe of nomadic mermaids whose lives were primarily centered around following pods of dolphins to eat. They live in the equivalent of the frigid antarctic seas. As they ...
16
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4answers
3k views

How to let a Whale urh… fly? [duplicate]

I have read about flying sharks that hunt birds and great monstrous flying whales, so I would like to know how a whale could conceivably start 'flying' in real life. I'm gonna just set Blue Whales as ...
14
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9answers
5k views

Would evolution select for mermaids without breasts?

So ignoring all the other hydrodynamic inefficiencies associated with sticking a human torso on a fish body, let's just worry about those most distinct of human female features, breasts. The problem ...
14
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4answers
4k views

Hammering under water?

Long before you get to using fire to smelt metals, hammering is a much more fundamental requirement for basic technologies. Hammering lets you Flake stones to make stone tools Process food--grinding ...
14
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11answers
1k views

Writing system of blind, sea dwelling sentients?

So let's consider a species of blind, sea dwelling, squid-like aliens. They are sentient, intelligent and highly social. As their societies develop and their available knowledge increases they ...
14
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2answers
828 views

How could an Earth-like planet develop huge pinkish-purple forests on ocean surfaces?

I'd really like to write a story taking place on an alien world that involves a totally new kingdom of life, and I'd like it to be at least somewhat realistic. The idea I have right now is a whole ...
12
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4answers
4k views

How long could a Kraken's carcass survive if preserved in salt?

I have a bay of water containing several Krakens. One day, due to the efforts of a magical organization, all of the water disappears. The Kraken fall and die on the bed of salt that is left behind. ...
12
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5answers
3k views

Plausibility of squid whales

I am considering the possibility of having massive cephalopods evolving on my world and having them fill the niche of whales. I've heard about how whales have evolved to increase in size for the ...
12
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1answer
500 views

Possibility of bipedal mostly-aquatic species?

I'm trying to design a species that is largely aquatic and yet capable of walking / running (loosely) on land. I've already figured out a gill and lung type respiratory system to allow them to breathe ...
11
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4answers
3k views

Would the existence of Megalodon during the medieval ages threaten Sea Travel and how to defend against them? [duplicate]

The Megalodon was an 59 feet (18 meter) long shark said to have roamed the entirety of Earth's ocean. Of course, it's quite extinct. However, what if somehow it managed to survive all the way to the ...
11
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8answers
3k views

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

It's a bit more complicated. I'm creating a sci-fi world for a tabletop game. One of my created races is a form of humanoid octupi. My idea is for there to be a nuclear war that forces their species ...
11
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5answers
897 views

Anatomically Correct Mesopelagic Aves

This is a submission for the Anatomically Correct Series Recently I had a vision of a colossal underwater bird-like figure. I would describe it as follows: Roughly the wingspan of the length of a ...
11
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1answer
240 views

Fastest fish possible

I am trying to design the fastest pelagic fish that is mechanically possible. The fastest real life fish can swim up to 80 mph. What body design would allow a fish to swim significantly faster than 80 ...
10
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4answers
856 views

What attributes and how big would a sea creature(s) need to be to tow a ship?

I'm trying to come up with ways as to how a ship could travel places with a very low number of people (like 4 crewmen). One of the ways I like for how to do this is to have large sea creatures ...
10
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2answers
320 views

Creating an Anatomically Correct Lusca

The Lusca (its name meaning 'Octopus Shark') is a cryptid from the Bahamas, supposedly a 6-9 meter (or even 23 meter) long man-eating Octopus that lives within the blue holes, dragging victims down ...
10
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1answer
604 views

Anatomically Correct Murlocs

So Murlocs. I'm referencing Murlocs from World of Warcraft since I never actually found any other novels or games that have them. Described as a bipedal, amphibious, intelligent, aggressive[Still ...
10
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1answer
601 views

How large could my sea serpents be?

EDIT: (Important) M. A. Golding commented that the regalecid method of locomotion would be unfit for a constricting predator, so I have completely redone the taxonomy of the sea serpent. They are now ...
9
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2answers
295 views

Anatomically Correct Giant Seahorses

This is a submission for the Anatomically Correct Series Giant seahorses are often portrayed in fiction as being ridden by merfolk or other underwater people. I'm wondering if such a creature would ...
9
votes
1answer
131 views

Designing a somewhat realistic “Astomi”: Filter-Feeding Humanoids?

I've been thinking of reviving an old Fantasy idea of mine, and I recently came across a description of a group of mythological beings that piqued my interest, and which would actually fill a niche I ...
9
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4answers
169 views

how big does my creature's organ need to blind or stun predator of all size?

Ok so my creature will look like this They're not big, about 2 feet tall. They're technically amphibians but have the scaly hide of a reptile. They live near the sea. Their life cycle is similar to ...
8
votes
4answers
698 views

How would thermophilic fish survive?

I'm designing alien creatures for illustrations, and I'm just sketching some that might live in areas with a lot of geothermal activity. So basically, animals that live around geysers and hot steam. I ...
8
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2answers
6k views

A Freshwater Octopus?

One of the oddest of cryptids is an octopus haunting the lakes of Oklahoma, a landlocked state. The reason this is odd is that although freshwater mollusks are common, Cephalopoda (the class ...
8
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4answers
1k views

What would mer-folk use as lights and soft surfaces

I'm writing a story where one of the main races is orca (killer whale) mer-folk. Being orcas need to breath oxygen from the surface so do they, this said they live in a halfly submerged cave...but it'...
8
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2answers
192 views

How would you go about seeding oceans of Europa with adapted Earth life?

How do you go about building a working Earth-like ocean ecosystem from scratch in Europa's subsurface ocean? On Earth, abyssopelagic species have evolved to live more than 6km below the surface. ...
7
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5answers
1k views

Could a Mosasaurus destroy a ship?

Would a fictional relative of a Mosasaurus, the fictional one being a tad bit bigger, be capable of destroying a ship? For the purposes of this question, assume a wooden ship of comparable size and ...
7
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2answers
1k views

What effect would living underwater have on a mermaid's skin?

Mermaids are commonly depicted as mammalian, human-like creatures from the waist up and scaly fish-like creatures from the waist down. What properties (color, texture, etc) would their mammal skin ...
7
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2answers
1k views

Life in extremely low gravity water

Let's assume the planet has only one half the mass of the moon and is covered by shallow ocean. To eliminate water pressure at extreme depths, assume the ocean is also quite shallow, with a maximum ...
7
votes
1answer
254 views

Water-walking animal

What are the requirements for mass distribution and body positioning that would enable a large creature (say, a panther) to walk on water (and still be able to dive down and swim if it wanted?) This ...
6
votes
3answers
417 views

How do marine dragons evolve flight without any feathers and no hollow bones?

These dragons spend most of their lives in the ocean, however during the mating season they will migrate inland and gather together on a mountain top. Throughout the journey they will cease feeding ...
6
votes
5answers
359 views

How would a language using colors and lights translate verbally?

How would a species be able to communicate using colors, flashing, and images on their skin (like some deeper water fish) with someone who speaks verbally, like a human? Is a translation devise even ...
6
votes
2answers
191 views

Explosive jellyfish

Could a creature like this exist? Jellyfish or cephalopod-like creatures that live in 'swarms' underwater. They float aimlessly around in a net formation. When one member detects prey below the ...
6
votes
5answers
796 views

Humanoid based on Octopus: Flexibility and organ protection

I am planning on making a new species based on octopus and humans. Human in skeletal structure, Octopus flexibility. I am thinking of calling them octopeople. As far as flexibility, I am thinking of ...
6
votes
1answer
334 views

what the aquatic creature need in order to live or survive in my acid water?

inspire by xenomorph acid blood from alien movies. so the water either rivers, lakes, and oceans in my world or some of the regions is highly acidic because some of the dirt or stone minerals content ...
5
votes
5answers
293 views

How to have a tribe measure the tides while living under the sea?

I'm dealing with a primitive tribe (of a species that can breathe underwater) that lives deep under the sea, and has little in the way of human technology. Resources include things naturally found in ...
5
votes
9answers
655 views

Can I have a giant tortoise?

I am aware of the square-cube law, so what conditions do I need for this to work ? The tortoise will be a similar size to the isle of Wight and will walk around in shallow areas in the ocean. What ...
5
votes
4answers
426 views

Could a genetically modified coral polyp be used as a pathogen?

Is this even remotely possible? Source Outline: Coral Polyps (along with their copious Calcium Carbonate excretions) are the individual organisms that make up the super-organism we identify as ...
5
votes
2answers
144 views

Variations on the “Ginsu Shark” Theme--What Would They Eat?

From 108 to 73 million years ago, the shallow seas of North America, Europe and southwestern Asia were the haunt of four species of a genus of shark scientifically named Cretoxyrhina. The chosen ...
5
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3answers
881 views

Could coral float?

I've been thinking about worlds like Keplar-62e, thought to be covered in deep oceans, and wondering about floating reefs. Could a bio-structure substantially similar to terrestrial coral hold enough ...
5
votes
4answers
164 views

How to identify sapient jellyfish?

There is a sapient jellyfish species resembling the box jellyfish found to be lurking in the ocean today. A team of researchers took a sub and dived into the abyss to look for it. What kind of non-...
5
votes
1answer
138 views

How large could an aquatic humanoid get?

Vertebrates on land are limited in size by various factors. However, in the water, they can get much larger. How large could an aquatic humanoid creature (like cthulhu) realistically get, and what ...