Tarantula sex chance?

[philipkovachev]

Hey I wanted to buy five tarantulas of one species hoping that they will be both male and female in my collection,but just to be sure,the chances of having one from both sexes are good right?Or are they more female?Do I have a good chance of having both of the two sexes?

 

[Giygas]

There is no definite or more females/males. You have quite a good chance of getting at least 1 male and 1 female from buying 5. Also, if you end up with an extra mature male, you could always trade it for some more slings.

 

[Storm76]

Didn't you plan to move soon? If so, I wouldn't invest into more T's if you're uncertain that you can take them with you...?


Just my opinion.

 

[Amoeba]

General Answer: Flip a coin five times or break out your TI-83 and there is your probability.

 

[paassatt]

General Answer: Flip a coin five times or break out your TI-83 and there is your probability.

Couldn't have said it better myself.

 

[jayefbe]

Chances of receiving a pair:
2 - 50%
3 - 75%
4 - 87.5%
5 - 93.75%
n. (1-(1/(2^(n-1)))*100 = % prob of pair given n individuals

 

[philipkovachev]

Hey thank jayefbe that answers rules dude!!

---------- Post added 04-19-2012 at 06:28 AM ----------

Actually I am going to move after 5-6 years.

 

[Storm76]

Although I personally wouldn't breed T's from the same sack...however - does someone have some data on inbreeding / breeding different bloodlines outcomes and the like? Curious about the subject anyways...

 

[Hobo]

What Jayefbe said.

Though, that's assuming there is a 50/50 ratio of males to females in a given sac (assuming you are buying from sac mates). I've read a few anecdotes that seem to suggest that some species produce more males than females.

 

[jayefbe]

A hobbyist have inbred OBTs probably over 9-10 generations at this point. I owned a few of his inbred slings (I think 8 generations at that point) and they were completely fine. Absolutely no difference between the inbred OBTs and other OBTs I have owned. Some species do not exhibit inbreeding depression, which appears to be the case with tarantulas. I personally see no problem with inbreeding. If new information comes forth displaying reduced fecundity or survival rates then I'll re-think my opinion but I doubt it'll happen. I imagine inbreeding is quite prevalent, if there was inbreeding depression we would have seen it by now.

---------- Post added 04-19-2012 at 11:32 AM ----------

What Jayfbe said.

Though, that's assuming there is a 50/50 ratio of males to females in a given sac (assuming you are buying from sac mates). I've read a few anecdotes that seem to suggest that some species produce more males than females.

I've heard that too. It was suggested that Lampropelma species may have a higher male ratio than 50/50. I'm not sure if anyone has followed that to say conclusively if that's the case. If there were any species for which it would be advantageous to have a skewed sex ratio, tarantulas would be them. Males typically only have a single reproductive breeding season, while females can have many. This may lead to an overabundance of females, which would mean that an increase in ratio of males would provide an increase in fitness. Mechanisms for skewing sex ratios are not incredibly common, but multiple methods have evolved in different organisms, so it's at least possible.

 

[Storm76]

Thanks for the info, JFB. I just brought it up since I heared it often that it's considered a nono with certain species, especially Avics. Anyways, that's a subject for another thread. Sorry for hi-jacking.