Mermaids: Dealing With Predators

Question

Mermaids have it rough. Being a marine species, they lack the means and quite possibly the inclination (as mermaids, like people, get used to what they have) to create fire and work metal, and therefore will be stuck in a relatively primitive tech level.

As a result, their weaponry is going to be bone, coral, and whatever metal they can gain from trade with sailors or salvage from shipwrecks. A sharpened rib, tied to a piece of driftwood with seaweed, for example.

This poses an obvious problem, as they need to deal with predators. Not just sharks and giant octopi, but other monstrosities as well-things like Snappers, mutant octopi, dire wolf-fish, giant sea snakes (which are big enough to swallow a mermaid whole), giant spider crabs (ditto), and saltwater scorpions (big, fast, and tough enough to prey on mermaids, basically a giant marine water scorpion).

Now, mermaids are about as fast and manueverable as dolphins, they have human ingenuity and intelligence, they live in schools of up to twenty 'maids, and they're highly altruistic-a mermaid would die for the good of the school if it was necessary.

The only problem is their lack of options-yes, intelligence has allowed us to conquer just about any predator here on land, but they lack advanced technology, which I think will impair these mermaids to do the same. Even if they trade with sailors, those sailors are restricted to medieval-grade technology, and metal doesn't do well in saltwater, so I'm not sure how they will adapt to deal with predators.

Things That May Affect Answer:

1. Mermaids are viable trifold chimeras created through magic, so given the right conditions, fish or whale genes can be expressed or mutated to give mermaids natural weaponry, like fangs, lionfish fins, spines, or a narwhal horn. In other words, natural selection gives mermaids a little leeway here-if they can survive. You see, these genes are dormant from the beginning of mermaids.

2. As an all-female species, mermaids survive thanks to sailors. This will likely influence the natural weaponry they develop, or how they adapt to predators. In fact, if it turns out they can't survive in the ocean, chances are mermaids will board ship and take their chances in captivity, but that's a last resort.

3. An answer is viable if it includes a trait (such as a natural weapon), item (which mermaids could feasibly attain or craft), or social behavior/course of action mermaids could use to deal with predators. General answers are suggested, but specific answers, if possible with the information above, would be preferred. If more information is required, let me know and I will add ASAP.

Answer 1

intelligence has allowed us to conquer just about any predator here on land, but they lack advanced technology, which I think will impair these mermaids to do the same

There used to be a lot of megafauna all across the world, back at the end of the last ice age. Then humans paid them a visit, and suddenly there were a lot of well fed humans and not a whole lot of megafauna.

Take home lesson? One does not need modern technology to drive a wide variety of large, dangerous or tasty animals into extinction.

Simply being able to make spears and nets and floats and work intelligently in groups and be able to escape onto dry land (eg. beaches and cliffs and rocks) gives them a substantial advantage over many other dangerous ocean-dwelling species. That's an excellent starting point for the widespread eradication of coastal marine megafauna.

Throw in a bit of trade or salvage to make various simple short-range projectile weapons (eg. spearguns, polespears and Hawaiian slings) merely by having access to rubber and that will make them dangerous to most normal things in the sea. Dealing with your magical predators is a separate problem, but best solved by simply staying out of their way. Hear or sea one? Leave. Don't come back. Keep watch, keep close to the shoreline and away from places that such creatures might lurk. Y'know, analogs to dry-land common sense when in the habitat of large, dangerous animals... humans have been doing this stuff for thousands and thousands of years. It'll be fine.

The rest is up to the rules of your magical "genetic" powers, which you've left undefined, and have not explained how they're gained, so it isn't really practical to form an answer around them.

Answer 2

Speed is key

So your mermaids are as fast as dolphins, that's up to 25mph/40.2kmph. If they can get their hands on basically any penetrative object or natural weapon(like the narwhal horn mutation) they can amplify the force exerted by their speed + strength of their thrust for a lot of damage. If the entire school does this at the same time they can turn something into a pincushion or swiss cheese rather quickly. They can do this with an acquired spear of wood too, but the horn whould probably work better and they might want to get one from an actual narwhal instead of growing one themselves and risking neck damage in the charge and the chance of getting stuck with no means of quickly escaping.

If a spear type weapon isn't to your liking consider the next bast weapon for an aquatic species, a curved blade. You can use a rib of some creature and carve that into a bone blade, curved and flat, perfect for underwater use. Here is where their speed will factor in as well, for they could simply swim by a creature really quickly and deliver the slash of a lifetime and run or make a turn for another slashing charge, the blades functioning like fins and are rather aquadynamic themselves. Just one good slice will do, if bleeding out doesn't kill whatever then the other predators in the water smelling blood will no doubt seize the opportunity. Now a proper metal curved blade like a scimitar or almost any other asiatic sword will do a better job at the slicing, but like you've said the ocean will not be good to them.

And what of the armoured predators that might not be so easily damaged, one might ask? The trick to dealing with them is to not deal with them. Armour implies they're not that fast. Your best bet would be to simply swim away. Even better, mutate some sailfish genes and watch your mermaids have the potential to go 68 mph(109.4 kph). Nothing living will catch them, not even the saltwater scorpion of yours that you state is fast enough to prey on a (basic)mermaid. But if you absolutely had to deal with them physically I'd recommend having the mermaids carry around a strong net and use teamwork to ensnare the predators. The net should buy them enough time to jab a spear or something into the gills or eyes or some other soft spot of the creature. Whether or not they run away after that I'll leave up to you, but I'd recommend it.

I don't know how available poisons/venoms are to your basic mermaids, but assuming they're at all like dolphins(as their mentioned comparative speed suggests) they should be able to harvest pufferfish venom with relative safety and tie the sacs to the tip of a spear to be used on a predator, delivering the toxin directly to the bloodstream through the wound. Those with a lionfish mutation may be able to remove a spine or two and attach it to the tip of their weapon to remove the need for a predator to hurt them to get envenomed. This may actually be the best way to kill an armored predator in combination with a net, but the longevity of the dangerous compounds outside of a living creature is a factor to consider so they may have to actually prepare themselves to go and kill a predator that they know about instead of carrying around venom applications for on the go use.

Answer 3

There is a way for mermaids to melt metal, they could use the hydrothermal vents that are found deep in the ocean! These vents can reach temperatures of over 700 degrees Fahrenheit, but you can say that the mermaids found a secret vent that has temperatures of 2,000 degrees Fahrenheit.

And instead of using metal, they can use gold! Most of the gold in the world is found inside of the ocean, in places that only mermaids can reach! Since gold melts at 1,943 degrees Fahrenheit, that's where the secret vent comes in. Also gold is the best metal to use in the ocean since it won't rust!

And since gold is very valuable to humans, it would create an amazing trading connection between pirates/sailors and mermaids. You could expand on this idea and make wealthier mermaid pods who find more gold, as well as conflicts where mermaids are cheated or even captured by sailors/pirates.

I hope this idea helps you! :)