Breeding T's from same eggsac

[juanbaltasar]

I was curious about this topic, is it common to breed "sibiling" tarantulas?

 

[AlbaArachnids92]

I don't know how many species this would even be a possibility with.
Aside from limiting the genetics for future generations, males of the species will more than likely mature/die long before any sibling females are ready.

To answer the question from my POV:
- Probably not common
- Probably shouldn't either

 

[Dorifto]

You can, but it's not recommended, even less to do it prolongedly as it weakens the genetic pool, and that's the last thing hour hobby needs.

There is a biological reason why males mature faster than females, and it's simply to prevent this.

 

[curtisgiganteus]

If you use the search function or Google it using AB in the search parameters you will find that this has been discussed in depth and the science behind it as well.

 

[campj]

If you use the search function or Google it using AB in the search parameters you will find that this has been discussed in depth and the science behind it as well.

Yep, and frankly with good arguments from both sides. I'm personally torn on the subject. Actually, I lean towards it being acceptable for a couple reasons.

Here's my favorite thread on this (which you could have easily found by searching @juanbaltasar. This has been discussed a hundred times here)

Guess it would have been cool if I'd linked the thread

Breeding sac mates.

I recently ended up with a 5" male and female ornata that I just recently found out they r sac mates. What's that mean towards breeding. I have been researching a lot on breeding sac mates but not getting clear answers.

arachnoboards.com

 

[Smotzer]

You can and people do, but it’s never truly recommended from a biological standpoint.

 

[A guy]

I've pondered with this in the past and asked the best source I have here.

Martin Gamache from Tarantula Canada, he's definitely the best dealer here Canada. To give him credit for those who don't know him, he went on expeditions to French Guyana and the island of Trinidad in the past and observed tarantulas in the wild; both known and unknown species in the hobby. He's friends with people in the hobby such as Rick West, Jean-Michel Verdez and Martin Hüsser - just to name a few. He was also invited by the Commision for Environmental Cooperation(CEC) as a guest speaker in the Tarantula Trinational Trade and Enforcement Workshop Supporting Sustainable Trade of CITES Species held in Guadalajara, Mexico.

had this to say when I asked him about this topic:

"Until specimens started coming out of Guyana, I am told that P. irminia was bred for years in the hobby from only 4 original specimens

For 35 years, Stromatopelma calceatum was bred in the hobby from 8 original specimens collected by a lady in Sierra Leone until more stock was imported. The specimens that live on the same tree are all related, like one big family.

Most species in the hobby are established by a few specimens collected by private collectors. There is almost never such a thing as "different bloodlines" even if some sellers might want you to believe that."

 

[curtisgiganteus]

I've pondered with this in the past and asked the best source I have here.

Martin Gamache from Tarantula Canada, he's definitely the best dealer here Canada. To give him credit for those who don't know him, he went on expeditions to French Guyana and the island of Trinidad in the past and observed tarantulas in the wild; both known and unknown species in the hobby. He's friends with people in the hobby such as Rick West, Jean-Michel Verdez and Martin Hüsser - just to name a few. He was also invited by the Commision for Environmental Cooperation(CEC) as a guest speaker in the Tarantula Trinational Trade and Enforcement Workshop Supporting Sustainable Trade of CITES Species held in Guadalajara, Mexico.

had this to say when I asked him about this topic:

"Until specimens started coming out of Guyana, I am told that P. irminia was bred for years in the hobby from only 4 original specimens

For 35 years, Stromatopelma calceatum was bred in the hobby from 8 original specimens collected by a lady in Sierra Leone until more stock was imported. The specimens that live on the same tree are all related, like one big family.

Most species in the hobby are established by a few specimens collected by private collectors. There is almost never such a thing as "different bloodlines" even if some sellers might want you to believe that."

And this makes sense, most of these spiders never travel more than a mile or so from their birth place. So there has to be a biological safety buffer given that inbreeding is inevitable. If there wasn’t, these animals would have gone extinct a long time ago.

 

[A guy]

And this makes sense, most of these spiders never travel more than a mile or so from their birth place. So there has to be a biological safety buffer given that inbreeding is inevitable. If there wasn’t, these animals would have gone extinct a long time ago.

Yes, he mentions that too. I forgot to add it in my initial response.

"Keep in mind tarantulas do not move too much, so it is not hard to understand that in a given area, all are pretty much related somehow."

 

[Dorifto]

Not Ts, but related. I believe you will enjoy

Group living and inbreeding depression in a subsocial spider

Social spiders are unusual among social organisms in being highly inbred—males and females mature within their natal nest and mate with each other to produce successive generations. Several lines of evidence suggest that in spiders inbred social ...

www.ncbi.nlm.nih.gov

https://www.google.com/url?sa=t&source=web&cd=&ved=2ahUKEwiJrs2m-_n7AhUIx4UKHTZ4DzkQFnoECA0QAQ&url=https%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2Fpdfdirect%2F10.1111%2Fj.1420-9101.2006.01280.x&usg=AOvVaw0gFAXNF8FhSWkdgLpRRzue

 

[curtisgiganteus]

Not Ts, but related. I believe you will enjoy

Group living and inbreeding depression in a subsocial spider

Social spiders are unusual among social organisms in being highly inbred—males and females mature within their natal nest and mate with each other to produce successive generations. Several lines of evidence suggest that in spiders inbred social ...

www.ncbi.nlm.nih.gov

This is amazing!

@Mazi2991

 

[DaveM]

It's wrong to take a black-and-white, absolutist view that inbreeding is always bad.

For lab mouse strains, there is no problem at all with inbreeding. Breed brother and sister, it's done all the time, and doesn't make the slightest bit of difference.
For wild mice, inbreeding would be a huge problem, resulting in unhealthy / defective / deformed offspring.

Why such a big difference?
There's a simple answer, in genetics terms: inbreeding increases [or maintains already existing] homozygosity of genetic alleles.
Therefore, whether or not inbreeding will cause problems for some captive animals depends on whether there are genetic alleles (versions of genes) in the breeding population that cause defects when they're homozygous (when both copies of the gene that an animal has are exactly the same version). Lab mice, lab rats, lab flies have all been inbred for so many generations that all of the gene versions that could cause problems when homozygous have been bred out of the populations. Lab mice (at least "isogenic" strains) are already homozygous in every genetic allele, i.e. practically every pair of every gene they have is identical. You could say that they simply have no defective genes, and no way to increase homozygosity more than being completely homozygous as they are already. Wild animals, on the other hand, have plenty of 'defective' genes, though the wild animals are faster/smarter/better than the purebred lab versions (there's no such thing as genetic perfection; heterozygosity and genetic diversity make a population stronger; eugenics would achieve the opposite of its aim; paradoxically, our defects are also our strengths, et cetera.).

Tarantulas in our collections are somewhere in between what wild spiders and lab purebred strains would be, depending greatly on how long the species has been bred in captivity and on how many breeding pairs have entered the hobby from the wild. We don't have the capacity and organizational ability in the hobby to maintain genetic diversity like that which exists in the wild. Our spiders will be inbred, probably with less-than-optimal outcomes for the earlier generations. Over time, defective weakling spiders will be removed from captive populations, genetic diversity will be reduced, our spiders will become more like lab animals, and inbreeding won't matter anymore.

When establishing a new species in the hobby, it would be best to start with as many wild reproductive pairs as possible, but for the rest of us, we just can't worry too much about inbreeding because it will happen, there's nothing we can do about it, and eventually it won't matter.

For completeness, there's a little more to the story:
1) differences among animals with different reproductive strategies: unlike humans, spiders are "r-selected" -- having very many offspring, with only a few that survive to reproduce --> that factor decreases the potential harm of inbreeding
2) differences between species genome size and complexity: spiders have large and complex genomes like we do (a little larger and more complex than the human genome, actually) --> that factor increases the potential harm of inbreeding

I wrote down some of this in another post, in different words:
https://arachnoboards.com/threads/breeding-from-same-sack.337346/post-3095064

Though most people from most parts of the world already know this: I want to caution everyone that inbreeding in humans is definitely very bad.
Charles Darwin himself ran into that problem and suffered the consequences.
And there might be a certain person here who knows that these comments are directed disapprovingly at him! Shame on you, @<unnamed person>!

 

[A guy]

Also, in lion prides in the wild when an old patriarch is beaten by his son for domination; the son will mate with its sisters and mother.

 

[curtisgiganteus]

Also, in lion prides in the wild when an old patriarch is beaten by his son for domination; the son will mate with its sisters and mother.

Which is interesting because in solitary big cats and wolves there is a genetic buffer against inbreeding. Females will fight off related males attempting to breed with them

 

[A guy]

Which is interesting because in solitary big cats and wolves there is a genetic buffer against inbreeding. Females will fight off related males attempting to breed with them

Yeah, inbreeding isn't uncommon as people think it is in the wild. It's even a way to preserve the strongest gene. The strongest male will breed with every female available including those very closely related to him

 

[CrazyOrnithoctonineGuy]

Also, in lion prides in the wild when an old patriarch is beaten by his son for domination; the son will mate with its sisters and mother.

This isn't what usually happens. Young males will leave the pride to take over another pride.

 

[A guy]

This isn't what usually happens. Young males will leave the pride to take over another pride.

Of course! I'm not saying that this is what normally happens but it is not that uncommon.

People need to understand that nature doesn't have a magical barrier that prevents inbreeding and that it almost never happens but quite the contrary

 

[FredSlaine]

I recently talked with an entomologist who mentioned that the dispersal by ballooning of some spiders, like jumping spiders, might very well explain the fact that reducing inbreeding in these spiders is desirable if one wants to end up with strong individuals. Theraphosids, which do not disperse much, if at all, and certainly do not use ballooning, are almost immune to many negative effects that inbreeding could bring.

 

[AlbaArachnids92]

Really enjoying this thread actually. I'll even admit I find it difficult to get over the initial 'inbreeding =bad' thought process.
Quite enlightening to hear how common place it is, as far as wild spiders go. Not something I had actually put a lot of thought into.

From a hobby/captive perspective, I see the origins of these captive species rarely give the option of genetic diversity, I can also think of examples where it could actually become necessary but would have thought it as a positive to avoid this where possible?
For example, T with some kind of defect kept in captivity (increasing rates of survival to maturity) then being bred back to a sibling/parent. Would this not leave the opportunity for increased severity of the defect in future generations?

Or is this me still just saying "inbreeding bad"?

Theraphosids, which do not disperse much, if at all, and certainly do not use ballooning, are almost immune to many negative effects that inbreeding could bring.

For my own understanding, is this that the effects do not seem to have an adverse outcome to the overall function of the T? Or that they lack the genes that would otherwise be affected through inbreeding?

 

[A guy]

Really enjoying this thread actually. I'll even admit I find it difficult to get over the initial 'inbreeding =bad' thought process.
Quite enlightening to hear how common place it is, as far as wild spiders go. Not something I had actually put a lot of thought into.

From a hobby/captive perspective, I see the origins of these captive species rarely give the option of genetic diversity, I can also think of examples where it could actually become necessary but would have thought it as a positive to avoid this where possible?
For example, T with some kind of defect kept in captivity (increasing rates of survival to maturity) then being bred back to a sibling/parent. Would this not leave the opportunity for increased severity of the defect in future generations?

Or is this me still just saying "inbreeding bad"?



For my own understanding, is this that the effects do not seem to have an adverse outcome to the overall function of the T? Or that they lack the genes that would otherwise be affected through inbreeding?

But let's be real, we really don't know. Everything we have on "inbreeding bad" is just based on what we know about different organisms and not tarantulas in particular. And like mentioned before, established captive population of certain species of tarantulas can possibly be traced down to only a handful of wild caught specimens.

Could it be that they evolved to get rid of the negative effects of inbreeding in order to survive millions and millions of years? I mean they had all the time they needed to do so. Maybe? No? Yes? We don't know.

If they did, is it really the strangest and most unbelievable thing in nature? I don't think so considering we have animals that can even regenerate a whole body from a single limb.