H incei communals - do the slings have to come from the same sac?

[Ungoliant]

Yeah, here in the States, it very common to buy find a "breeding pair" of juveniles that are exactly the same size. Usually of the same sac. A shady business practices in my mind.

I can't imagine that it's good for the hobby to promote the breeding of siblings.

 

[EulersK]

I can't imagine that it's good for the hobby to promote the breeding of siblings.

There's a lot of debate on the matter, and neither side has any evidence to back up their claims.

Myself, I subscribe to the belief that it's not good to do. I think that a generation or two of inbreeding is alright, but not much beyond that. If it can be avoided at all, I think that it should be.

 

[Ungoliant]

There's a lot of debate on the matter, and neither side has any evidence to back up their claims.

While I would be surprised if there is any research on the long-term effects of inbreeding in tarantulas, it is known to be detrimental in so many other animals that I can't justify deliberately inbreeding tarantulas. There is no reason to breed siblings that's so compelling (particularly with commonly available species) that it outweighs all of the possible risks.

 

[EulersK]

While I would be surprised if there is any research on the long-term effects of inbreeding in tarantulas, it is known to be detrimental in so many other animals that I can't justify deliberately inbreeding tarantulas. There is no reason to breed siblings that's so compelling (particularly with commonly available species) that it outweighs all of the possible risks.

A big issue is that we have a finite pool of blood here in the States. For instance, if I ever find a male for my female Phlogius, chances are they will be directly related. Importing/Exporting laws in Australia have made that genus very hard to come by here, and the major influx we got was a few years ago from a single exporter over there. What you're saying makes sense with most species, but with tightening laws all over the globe, the issue will only get worse.

We know that invertebrates handle inbreeding much better than vertebrates. There have been many studies on the matter. But that doesn't mean invertebrates are immune to the issues.

Here's some anecdotal evidence. About a year ago, my dubia colony started going downhill. Males maturing with no wings, dwarfism running rampant, females with no antenna, and so on. That colony of tens of thousands is the result of two breeding pairs that I got for free a few years ago. The inbreeding started to catch up. Luckily, a small influx of a few dozen males every year keeps those issues at bay. It doesn't take much to mix up the genetic pool, is what I'm saying.

 

[Ungoliant]

A big issue is that we have a finite pool of blood here in the States. For instance, if I ever find a male for my female Phlogius, chances are they will be directly related.

I get what you're saying, but I draw a distinction between knowingly and deliberately breeding two siblings and simply breeding two tarantulas that are likely to be related due to limited breeding stock.

That male and female spiders often mature at different rates is thought to be a mechanism for reducing the odds of siblings mating in the wild. There's probably a reason that developed.

About a year ago, my dubia colony started going downhill. Males maturing with no wings, dwarfism running rampant, females with no antenna, and so on. That colony of tens of thousands is the result of two breeding pairs that I got for free a few years ago. The inbreeding started to catch up.

I have a small colony of inbred mealworms that will eventually need some fresh genetic material. However, I don't worry about them, because they're just feeders.

 

[EulersK]

That male and female spiders often mature at different rates is thought to be a mechanism for reducing the odds of siblings mating in the wild. There's probably a reason that developed.

I completely agree, 100%. In my eyes, that's the biggest piece of evidence against inbreeding.

I have a small colony of inbred mealworms that will eventually need some fresh genetic material. However, I don't worry about them, because they're just feeders.

If they're like my roaches, you'll start to get dieoffs. But I hear you, I probably wouldn't have cared if I wasn't selling them. Dwarf dubia feeders kind of defeat the purpose!