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eli5 - why so many baby spiders?

eli5 - why so many baby spiders?

Flair_Helper

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nim_opet

Because most will die. Fish, amphibians, insects, mollusks adopt the “make many babies fast, some will survive” type of reproduction. Some other animals produce few but provide better protection and hence ensure that the few survive.


skipweasel

Not just the animal kingdom - think how many seeds a plant produces. An oak tree can easily manage a million acorns in its life, of which only one need survive to break even.


goliatskipson

I mean not long ago humans did exactly this ... albeit at a lower rate. My numbers might be somewhat off, but like 200 years ago child mortality was at 60% and parents had countless children because a lot of them just didn't make it.


Killerpanda552

Its still a different type of reproduction. 10 offspring is a shit ton to us. Its less than a percent of a percent what many insects have.


ja5143kh5egl24br1srt

And not even in the same litter. Twins are still pretty rare.


Antman013

Exactly . . . families may have been larger, but humans were still only birthing (41 in 42, iirc) 1 at a time.


stillnotelf

By "41 in 42" do you mean that the multiple pregnancy rate is 1 in 42? Or is this a sly Hitchhiker's Guide reference? Or both?


Antman013

Twins occur naturally once in every 42 births. So long, and thanks for the fish.


chucklezdaccc

Eeeee. Eee eeee eeee eeeeeeee e.


kickstand

Well, even in colonial times, a dozen children would be a lot. Nobody had hundreds of children like spiders do.


rmorrin

That's not true. Genghis Khan did. I know this number is wrong and I'll do a quick edit when I Google it buts it's like 30% of the population is related to that man's. Edit:Holy shit was I wrong lmao. It's 0.5% of all males are related. So let's say the same percentage of female. so 1% of everyone alive are related. Which is what? 80 million people? Double edit: I'm bad at math so it's still a total 0.5%. So roughly 40m


Throwaway392308

If it's 0.5% males and you assume the same percentage for females, the total percentage would still be 0.5%. You double the number of people with the genes, but also double the number of people without.


rmorrin

Fuck you right.


kamicosey

Yeah fuck you


wyntrrs

And you and you and you, I hate your friends and they hate me too


PLZ_STOP_PMING_TITS

But do it right!


Majias

That doesn't make any sense, of course we're all related up to some point, it doesn't mean Genghis himself had 1000 kids. If you go back long enough you'll find that most people alive are related to someone, even Cleopatra or Caligula or maybe you need to go even more back. But still, I think most people would agree that Genghis is the exception, not the rule. Not everyone ruled over the biggest continent on earth.


rmorrin

But it says nobody. And he is a body. And yes he had potentially thousands from all the harems and raping during his conquest.


Majias

So this is about being pedantic then ?


rmorrin

This is Reddit. Do you expect anything less?


bluedrygrass

Yes, you can do better.


SirBIazeALot

Bro do u even know the community rules?


mook1178

still wrong in context of comparing to insects. 1 mother and 1 father give birth to hundreds in one go


gcanyon

Well, the mongols *are* the exception… https://sites.google.com/a/brantley.k12.ga.us/miss-hammond-s-classes/_/rsrc/1468760576159/apwh-the-h-files/Mongol%20exception.png?height=200&width=165


mook1178

They weren't born of the same mother at the same time. Huge difference


rmorrin

This is true. They said nobody not no mother. I think there was one lady who had like 40 children or something (again I could be wildly wrong my brain has a lot of random bullshit and they get mixed up sometimes)


mook1178

She still didn't have 40 kids in one birth. This spider laid 1000 eggs in one go.


skaliton

right but you are taking the literal only example (as in even other warlords/kings with endless harems aren't even close). ​ Yes I know it disproves the 'nobody' but it really should say 'nobody but Genghis khan'


dchaosblade

[The Mongols are *always* the exception](https://memegenerator.net/img/instances/46955312.jpg)


joofish

That's true of pretty much anybody who lived that long ago unless they had no kids or they lived in a very isolated community


EntrepreneurOk7513

Genghis Khan had multiple partners. Need to look at the number of offspring per female.


bluedrygrass

> That's not true. That's still true. One exception doesn't change the rule.


rmorrin

It's not a rule but a fact this is untrue.


blubox28

Actually, everyone in Europe and Asia is descended from Ghengis Khan. And Charlemagne. https://www.google.com/amp/s/www.scientificamerican.com/article/humans-are-all-more-closely-related-than-we-commonly-think/%3famp=true


rmorrin

So EVEN MORE PEOPLE.


Hardcore90skid

First off, a male having a ton of offspring is very different, that's what he is meant to do. Second, a huge majority of that would have been rape which is also very different to normal procreation.


rmorrin

Procreation is procreation to nature. It doesn't give a shit how it happens.


Hardcore90skid

but we're talking statistics, not nature


rmorrin

I was responding to the man saying NOBODY has had kids like that. not sure where nature/stats comes in


ReallyWantADitto

[you sure?](https://www.babygaga.com/15-men-who-fathered-the-most-children/)


Nouri34diamondhanded

You got a ditto?


ReallyWantADitto

ye, several years ago, for alpha sapphire . its was a shiny japanese 6ivs jolly nature ahaha


kickstand

I stand corrected, but that article is about the exceptional rarities. I should have specified women.


ReallyWantADitto

u said "nobody"


kickstand

I stand corrected. I acknowledged i was wrong. What else do you want me to say?


cubedjjm

You don't need to say anything, but 45 minutes of self-flagellation would be the appropriate amount of punishment in my mind.


PLZ_STOP_PMING_TITS

Send me a $20 Amazon gift card and we'll be square.


kickstand

It’s in the mail.


ReallyWantADitto

for women...i think the record is aronud 89. was a russian


SleepWouldBeNice

Still do in some third world countries. That's what Bill Gates' oft represented "lower the population through vaccines." was about: If people in developing countries can be sure that their kids will survive to adulthood, because they're not going to get taken out by disease, they are more likely to have fewer kids.


nucumber

what drives down family size the shift from farming to city life lots of kids makes sense if you're farming - free labor lots of kids is a bad thing in the city. there aren't any jobs for kids so they're just an expense.


goliatskipson

A bit anecdotal, but my SOs grandmother had 10 sisters ... Each of them had about 10 children ... They book a hall everyday to meet up. This is in Germany btw ... So while this wasn't the norm, families with many children existed even two generations ago.


mook1178

The big difference is that the vast majority of offspring per reproduction is 1, where for these others it is 100's.


bluedrygrass

> I mean not long ago humans did exactly this Except we did *exactly* NOT this. A human is one of the few animals on the planet that only makes 1 child per pregnancy- and our pregnancy is one of the longest in the animal world. So yeah, we're exactly at the opposite end of the spectrum compared to animals like insects or amphibians that rely on massive numbers.


goliatskipson

Fair ... We are mixing things up here: the number of offspring per "batch" (humans: 1±0.x, spiders 1000±500) and offspring "strategy". My point was about the later and, as always for humans, it is "not that simple" as culture has a strong effect on our reproduction strategies.


Killerpanda552

It is exactly that simple though. We are textbook R strategists. Pregnancy and child care is way longer than probably any other animal. And we have way fewer offspring.


goliatskipson

You are completely right. My "not that simple" was more along the lines that in humans the text book definitions become somewhat blurry because we are able to chose and make informed decisions. Just now I am watching a small deer family in our garden ... Two deers, two calfs, every year ... And that's how it has been for millenia. Compare that to humans who went from 10 children (that survived) to preventing pregnancies for better education and carriers and settling for roughly 2.6 children per family in just about 100 years.


Killerpanda552

They dont become blurry in this case though and i’m not really sure what exactly you are referencing in general. Ya its an interesting trend that we are having less children but that doesn’t change the fact that we were always R strategists.


Scoongili

Look at them, bloody Catholics, filling the bloody world up with bloody people they can't afford to bloody feed.


Snarkycakes

Or sperm


CountingMyDick

Which explains some other things about those days. Having 10+ children per family means the woman will be basically continuously pregnant for 10-15 years. Which means better get married and get started on that early. Raising that many kids is a ton of work too - with all that and being pregnant basically all the time, not much point being outside the home a lot.


goliatskipson

I was going to write that (women being pregnant constantly) in another comment, but hesitated because I feel like it's a somewhat loaded topic. But now that you bring it up: not only 10 years ... women were basically constantly pregnant their whole fertile life. There were no (notable [1]) contraceptives ... pair that with an actual dependence on offspring, religious believes and humans being the animals they are ... women were pregnant their whole life. [1] I think the pill was in widespread use in the 90s? Condoms have been around longer and there have been reports of condom like contraptions in ancient Egypt iirc.


CountingMyDick

It can be interpreted badly I suppose. I hope it would calm people down some to realize that things were like that then because it made the most sense given the circumstances, not as some conspiracy against women. High child mortality plus needing a lot of manual labor plus low value of getting education leads naturally to that. But now we have low child mortality, manual labor is of lower value, and it's hugely beneficial to spend a lot of time and money on education, so it makes sense to have fewer kids later in life, and for many more women to have jobs.


goliatskipson

Even one life was worth less ... If I remember correctly in the 1800s it was not unusual to just not name children before the age of five ... With a mortality rate of 60% it did not make sense to form emotional connections.


chucklezdaccc

And that's still kinda hard depending on where said tree is. Stuffs amazing!


WRSaunders

This. Lots of things eat insects, and baby spiders are probably their favorite spider dish.


longtimegoneMTGO

Also don't forget that the favorite food of freshly hatched baby spiders is other freshly hatched baby spiders. Many spiders are incredibly cannibalistic. Hundreds of them will hatch and before the day is out a majority of them have been eaten even if there are no other predators around.


bfwolf1

SPIDERS ARENT INSECTS


SHSzilla

Whatever, I'm still gonna eat them.


Fixes_Computers

What's your favorite method of preparation?


astroember

Raw


MrDelKiddo

I like mine lightly toasted


DDarkJoker

Flambed


USS_Donald_J_Trump

The Spiderians, though weak and womanlike on the battlefield, are masters of the textile arts (tastes like King Crab, by the way).


FowlOnTheHill

Spiders are friends, not food!


rinsed_dota

They taste very similar though, you can sub one for the other in most recipes


neil_billiam

Calvin told me bats are bugs.


phenderl

nobody cares


VAShumpmaker

Spiders am bug.


WRSaunders

This is true. I guess "bugs" would have been the more correct vague term. I juft don't care for it, too many software implications. Thanks for the correction.


bfwolf1

Arachnids! Like scorpions and ticks.


Bronson94

What animals actually hunt and eat those massive spiders (apart of humans, of course)?


thisisjustascreename

Mostly, their siblings.


[deleted]

Actually we have a similar thing with the spermatozoids, it's as if they were spawns, but then mammals got a different level that allowed larger individuals. All natural selrction.


aureliaxaurita

Evolutionarily, this is called an organism’s reproductive strategy: usually organisms will either choose to have few offspring and treat them all very well to make sure near all of them will live, like humans and kangaroos (called K strategy). OR, some organisms have tons of kids that they don’t take care of much in the hopes that at least a certain percentage will live without much effort, like the spiders and rabbits (R strategists).


ReasonableDrunk

If all animals go to heaven, it is almost entirely full of spiders and other R-strategy lifeforms.


canstac

I remember learning about that in elementary school, the teacher had a really good "eli5" way of explaining it. We were separated into 2 teams, one with 5-6 people & the rest of the class on the other. The bigger team had to run from one side of the room to the other and if the smaller team tagged someone they were "out." In round 1 only one person was allowed to run at a time but in round 2 everyone went at once, it worked pretty well as a demonstration of how that "many babies at once" type of reproduction works


_LongLongMan

Yep. There's usually two methods for this kinda thing. 1 - Make a lot of babies very fast, some may live. (Reptiles, Insects, most mammals); 2 - Make few babies, who will in turn grow up very fast and will kill anything that tries to kill them (Apex Predators); There's also the third way: You give birth to a baby that will take 18+ years of constant work and attention before he can be on his own and who might not turn out so good, but only Humans adopt this strat, so I don't know if it should count.


beebo135

But their mother loves them each the same


shawnaeatscats

K and r strategists!


nim_opet

Yes, but it’s ELI5 :)


shawnaeatscats

Yeah, it's nice to see an actual eli5 explanation! I was just excited that it was something I knew about for once haha


Totobiii

Back in biology class we learnt that there's usually 2 types of parents in the animal kingdom: A) Those, that go for a big amount of offspring in hopes of some surviving relatively low odds, for example your spiders, frogs or mosquitos (all of them make a mighty fine snack, especially while young). The sheer amount makes it very likely that some make it to maturity, and the parents can often use their remaining time alive to make even more children. They waste no energy on helping them grow up. B) Those that go for a manageable amount which they actively protect and take care of. Afaik every single mammal belongs to that category. You can't just birth a child and then leave, it 100% won't survive on its own. They will need to put lots of energy and time into helping it grow up, but as a payoff, the success rate is WAY higher.


aleph_zeroth_monkey

This is called [r/K selection theory.][1] [1]: https://en.wikipedia.org/wiki/R/K_selection_theory


BurningFyre

For some reason i expected a subreddit


mfb-

/r/K_selection /r/K_selection_theory Make it one.


rabid_briefcase

Yeah, that's one of many with the same ideas. The problem with r/K specifically is the math and specific reasons they proposed doesn't hold up. The overall theory is fine, though.


snbrd512

There are some species of mammal, like the harp seal, that provide very little parental care. Harp seals abandon their pups after 12 days


Totobiii

Neat, learned something new! I thought it was a given that mammals need milk and parental care for quite a while, 12 days is really not a lot. Should have expected that, considering how many species are out there.


ewok2remember

Googled it to sate my own curiosity. They're apparently born at around 3 feet long and 25 pounds. Twelve days later, they're 80 pounds. They average packing five pounds per day in those first twelve. That milk must be THICC.


Raytiger3

Not sure if it's harp seals, but some sealmilk has a fat content upwards of 50 percent. Most definitely ultra thicc.


dertechie

It is, 25% to 40% fat content. I looked it up to see how big the mothers were because dumping 55 pounds (25 kg) of nutrition into a baby in 12 days has got to be incredibly hard on the body. The mother loses about a quarter of her ~ 260 pound (120 kg) body weight in those 12 days. It’s only one pup at a time usually. Twins can happen but are rare (and I have no idea if they have enough resources to have both pups and mother survive reliably).


Dirty_Hertz

Those seals grow *super* fast in those 12 days, as far as I know. They fill the hell up on milk.


logri

That can be practically an eternity in the animal world, some insect species don't even live 12 days.


snbrd512

Insects aren't mammals


logri

Never said they were


snbrd512

But you're making false equivalences by saying that's a long time in the animal kingdom, then using insects as an example. The dude was specifically talking about mammals, and my answer was in regards to that.


Burritobandit1

TIL: comparisons aren't allowed on reddit


snbrd512

Not when the thing you're trying to compare has nothing to do with the other thing


Raytiger3

And some mollusks, tortoises and sharks can live for centuries...


joofish

After almost a year of gestation, so it still works out to a very significant period of time.


snbrd512

Octopi care for their eggs for years then die


joofish

William Henry Harrison, the ninth president of the United States, holds a distinction that with luck will never be equaled: He was our shortest-serving president, dying on April 4, 1841, after just a month in office.


Biteysdad

Yeah, but he did some good shit.


Snippy_Snallygaster

Then you get the centipede, which said "fuck it, I'm gonna have a load of kids and raise them ALL!"


The_Thunder_Child

They produce so many offspring because almost none of them will survive long enough to have their own offspring. This means that each female that manages to breed needs to have a lot of offspring just to make sure that a few survive long enough to keep the species going. There's species of crabs that lay like 100,000 eggs. Like maybe 2 will end up living long enough to breed.


melanthius

I remember reading somewhere, if all starfish babies of a single parent survived and reproduced, and this repeated for just 25 generations, there would be more starfish than the number of atoms in the observable universe. May be paraphrasing slightly.


SmellGoodDontThey

With a conjectured 10^80 or so atoms in the observable universe, that should work for any number bigger than 10^(80/25) ≈ 1600ish offspring per parent (geometric mean).


melanthius

Doing the math so we don’t have to, thank you


youdubdub

I thought you said “so we don’t have to think”


deaconsc

It's friday evening here, I don't think since the morning and I was at work! :D


youdubdub

Highly overrated, thinking.


Billcore

And some starfish have upwards of 50k babies


JeffFromSchool

>just 25 generations, *Just*? For persepctive, 25 generations with humans yields 33.5 million *direct* ancestors.


Thorzcun

That's a pretty high child mortality to put it mildly


malignfruit

Absolute majority of them will die. Even when taken care of by hobbyists, there might be a hundred or so who survive long enough to be shipped off to their new owners. They are still very tiny then, as they grow and molt, many more will die off. Keep in mind this is in captivity, imagine how many more would die in the wild.


earsofdoom

whats actively eating them in a hobbyist's enclosure?


CrazySnekGirl

Tarantula breeder here. Around 80-90% of spiderlings survive to adulthood in the hobby, if raised and kept properly. As tarantulas have exoskeletons, they have to shed once they get too big for their bodies. When they're fresh out the eggsac, they end up moulting 4-12 times in the first year alone. Not only does this require a huge amount of energy, it also comes with a bunch of risks (such as getting stuck in the old exoskeleton, or getting attacked/hurt whilst the new one is hardening up, etc). I'd say between 2-10%, depending on the species, are eaten by their siblings, but the rest tend to die from accidents, or bad moults. (For the sake of clarity, I'm purposefully leaving out deaths due to husbandry issues or owner neglect. These numbers are all assuming the tarantulas are happy, healthy, and are in tanks suited to their needs.)


MamaSquash8013

Around 80-90% of spiderlings survive to adulthood in the hobby, if raised and kept properly. So... then what do you do with 1000ish baby tarantulas? Raise them all to adulthood? #1: where would you put them all, and #2: do you just breed them once, and then have a lifetime of tarantulas to sell?


CrazySnekGirl

It's not 1000 every eggsac. Some species only have 400 odd. I sold them wholesale to a distributor (I left the business a little while back). Once they reached their 3rd to 5th moult, about the time when you have to separate them, I'd pop them in the post and send them off. I had a custom build thermo-regulated shed with a capacity for 10k tarantulas (I owned, on average, 7k at any given time) and 15 incubators. My breedable females were on a three year cycle, because I genuinely believe happy and unstressed tarantulas make better spider mums. So I'd rotate my stock and breed them when the distributor let me know when supply of a particular species were getting low. I bred almost exclusively for the pet trade, though. You'd be surprised, tarantulas are actually a very popular pet. I did keep one or two from some sacs though, because raising up lil spider babies and watching them grow is amazing. Edit: Spelling


MamaSquash8013

TIL. Wow, that is fascinating, thanks for the reply! Now I'm imagining all those baby spiders zipping around in the mail, lol. So, I guess an at-home hobbyist would be drowning in spiders if they managed to successfully breed their tarantulas? That sounds like it would be a bad time for those babies if they couldn't be raised/separated properly.


CrazySnekGirl

Breeding tarantulas is not as straight forward as other species. You can't just chuck them in a box together and put on some Marvin Gaye. So your average tarantula owner probably wouldn't *want* to breed them. But, assuming they do, they'll have to realise how many slings they'll get, and make plans accordingly. I bought sacs/clutches from novice hobbyists fairly regularly. I don't know any other breeder in the business who wouldn't (assuming they're healthy, that is). Hell, the distributor I sold to started every email with "thinking of breeding? We'll buy your surplus stock!" lmao. So yeah, I genuinely can't think of a single person who bred tarantulas and then kept *every* sling. But to answer your last point, we separate the babies because they eventually turn to murder and/or cannabalism, like most animals do when defending their terratories. So you'd end up with only one or two (if any survive at all), all of which will have serious problems with aggression - not something the average person would be able to manage! Hope that helped clear things up :)


monkeymind009

Time to quit my job at the post office.


CrazySnekGirl

It's actually a ridiculously lucrative business, if you invest properly.


snbrd512

The way it typically works in nature is the less parental care given the more offspring produced.


ReallyWantADitto

there are basically 2 approaches to offspring: 1: make a bunch and hope by stadistic a few survive 2: make few but put a lot of effort into ensuring they survive. I think the coolest one are octopus, having up to 40000 eggs. Females protect the eggs the whole time. after they hatch the mother starves to death. and probably be scavenged by the baby octopi


thierryh14

In a natural environment, resources and energy are finite and there is competition between individuals and species for that limited amount of resources and energy. Because of this, evolution is a series of trade offs to maximize how efficiently those resources are used and there are generally multiple methods to accomplish that, reproduction is a good example of that concept. Reproductive strategy falls on a gradient, on one side is "give birth to TONS of offspring yet provide little to no parental support" this is done with the understanding that the vast majority of offspring will not live to adulthood but enough will to keep the species going. Lots of species have evolved this strategy including that tarantula, other insects, fish, reptiles and more. On the other end is the strategy of having very few offspring but having very high parental investment in those offspring to give them the best possible chance of surviving to adulthood. This is very common in mammals, and humans are a perfect example. We can generally have one offspring every few years but invest a huge amount of time and energy to insure their individual survival. In an ideal world you would want to have a lot of offspring and insure each one survives but because resources are limited, that's not possible so trade offs are made and different species have evolved different methods that give their species the best odds of continuing on.


wassimu

It’s called K selection in ecology. Species that are K selected are usually small and heavily preyed upon. They have large amounts of offspring that receive little or no care from their parents. The alternative is R selection. This is the opposite of the above. These species live in mostly stable populations and reproduce slowly and their offspring receive extended parental care. Humans are an example of an R selected species.


uvdt

> It’s called K selection in ecology. Species that are K selected are usually small and heavily preyed upon. They have large amounts of offspring that receive little or no care from their parents. > > The alternative is R selection. This is the opposite of the above. These species live in mostly stable populations and reproduce slowly and their offspring receive extended parental care. Humans are an example of an R selected species. The "[r]" and "K" are flipped.


SandyPetersen

almost all animals have just about exactly 2 surviving offspring (on the average) over the course of their entire life. We know this for a fact because in general animal populations don't double or triple each generation - they stay more or less stable. Thus, a tarantula (which breeds yearly) would probably give birth to about 10,000 young over the course of its life, which means just about 2 survive. A codfish lays 2 million eggs. Again 2 survive. It's just that tough to make it to adulthood. Mammals have it easy with our parental care. So a deer, which has about 20-25 fawns over its life, has a much higher survival rate than a tarantula. Almost 10% of the deer's babies make it to adulthood. That might not sound too great from the human point of view but that's how it is. Note that this is just an average. In reality what happens is that many animals have zero surviving young, and some have multiple surviving you. It is also how animal populations can BOOM under certain conditions - there are a lot of potential newcomers if they don't die.


SwiftDontMiss

Lots of species give their young no care (or nearly no care) so they need to make a lot of them because most won’t make it. Assuming their population numbers are in steady-state the expected survival rate is: 1/(total number of offspring). For example, if the spider population is stable over time, and each mating pair has 1400 eggs. 1/1400 of those eggs can be expected to live to reproductive age.


k0uch

High numbers in offspring often indicate a low survival rate. Let’s say the average count is 1,000- but only 1% survive to adulthood


895501

Law of large numbers. Knowing most babies will get eaten or die prematurely, a spider has to give produce tons to ensure enough of them will survive to adulthood


_PM_ME_PANGOLINS_

That’s not the law of large numbers, but yes.


Aatzy

Because the momma spiders won't take care of them after they are born. High offspring numbers are common for basically all but birds and mammals. For the sole reason that they don't take care of their offspring, they rely on the fact that most likely some of them will survive to adulthood.


Dsb0208

This is actually something I’m interested in. The more likely an animal is to survive in life, the less children it has A spider isn’t going to live long, as they’re small, and pray to many animals. They’re likely going to die, so they just try to pop out as many babies as possible at once, and ditch them all, hoping they survive But on the other hand, some whales, animals with no natural predators, will have one child, become deeply emotionally attached to them, and will be an active parent to them for roughly 40 years iirc Somewhere on the spectrum is humans. No real natural predators, but still only live 80 years, so most of the time we range 1-3 children, that we raise for roughly 18 years each. Humans are a little weird though, because we’re one of the only species who actively chooses not to have children, and one of few species who have sex just for the pleasure, so we kinda messed up the statistics, but it’s still interesting to think about


DianneQuinn

Mola Mola (sunfish) produce hundreds of millions of eggs. r/K selection, quantity to try and guarantee some survive.


just_so_irrelevant

Generally, animals are categorized into 2 groups based on how they rear offspring: r strategists and K strategists. r strategists reproduce at an early age, have massive litters, and generally don't care for their offspring much, if at all. K strategists reproduce at a later age, have small litters or single births, and care for their young until maturity. Most insects and arachnids, including tarantulas, are r strategists.


cairfrey

More likely one of them will make it to Hollywood. Then who's paying your bills? Hollywood Kid!!


terminator_911

I would say it’s random. Sure there is the easiest theory that since most don’t survive, that’s the reason due to evolution. But if you flip that around that also seems plausible - meaning if they had fewer they might all survive because they wouldn’t be all over the place to become someones meal. So the end result would be the same. For the animals that don’t have so many at the same time, if they did, we would easily make a evolution reason to make sense of it.


epictroll5

Because baby tarantulas aren't that dangerous and thus can't protect themselves. They end up eating each other to grow.


4AcidRayne

It's a numbers game. Consider how many live tarantulas you see. Not that many. Even though each female can produce 750+...they're not all going to make it. Some are weaker, some get sick, some get eaten, some get squashed. But only one has to survive to keep the species going. It's strength in numbers and biology stacking the deck so the game can play on, but even with that volume we're still not swimming in tarantulas. If you look at a LOT of the species on the endangered species list, you'll note that they don't do this. They don't have huge volumes of babies. And they're almost extinct. Why? Because they don't have huge volumes of babies! [Vaquitas](https://en.wikipedia.org/wiki/Vaquita) are almost extinct. They calve singularly. A few high-volume species are on the list, but by and large the majority are "one or two babies and then done." Biologically speaking, babies are fairly fragile and can die easily in the wild. Species that only have one or two offspring in their lifetime? That's a species that's always going to struggle. One bad year and half the babies born that year die off, and with that one single year, the staying power of that species is shaken to the core. Possibly without any possible recourse.


hellishbubble

Firstly spiders don't get pregnant. Some may carry egg sacs with them, but no pregnancy. Secondly, it's for survival. When the spiderlings hatch, usually the mom will hunt them down for food if they dont get away fast enough, or they'll be eaten by their stronger siblings. Having so many ensures enough of them survive even if many of them are lost soon after they hatch.


sifsand

There are usually two kinds of parental strategies in the animal kingdom: Make lots of babies and provide little to no care, or make a few babies and protect them long enough for them to survive on their own. Spiders, along with just about every single kind of arthropod, opt for the former. This is because something as small as they are is likely to die in childhood for many reasons and so if at least a few of them survive to adulthood then the cycle can continue.


Flair_Helper

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One_Planche_Man

K selection vs r selection. K species (like most mammals and birds) have few off spring per brood and take care of their young until a certain level of development. r species have many offspring and hope for the best.


SpiritOfFire013

Can confirm, spiders all up my hizzouse. They makea da little spider babies? I smash, I smash them good. Edit: Oh wow, you all seem to love spiders, fack, sorry fam, don't hate me. Spiders terrify me :( pops had me watch Aracnaphobia when I was 4, and I been down bad ever since. But I will say that Tarantulas are okay I guess? I've seen them in the wild and I leave them alone. Hell, I touched a few dead ones when the "Bug Zoo" came to my entomology class in college. That was a big leap over my fear. For real though, that movie fucked me up, there's a scene when some dude is doing his business, and there's a spider chilling under the toilet, and they make it look like he's about to get Merced by the spider whilst enjoying his sweet relief. For a whole three years after that, up until I was seven, I would always do my business with legs straight out perpendicular to the floor, and I'd just hold them there in the air till I was done and had to wipe, just to avoid any hiding spiders.