Why Higher male to female ratio??

I noticed when I started buying multiples, that I always end up with way more Males then females.
Like OBT I had over 7 MM's , and ended up with only 3 females. our of 10 Ts.
so 70% were Male. And my GBB I got 1 female 2 males , 66%.
P regalis I got 1 female , 9 males. And another I am not sure of yet hope its female.
So 90% male pokies.
Note: All of which were raised from spider-ling size 1/4".
Keepers of a very large amount of Ts , prob could help a lot on this topic.

For this ratio slings are ridiculously overprices sometimes , 1/4 price of a female.
Clearly ima need new slings eventualy though, since I lost so many Ts to being MM;s.
Anyone else have similar results?

Your results could be skewed if you're buying the larger options online.

If different sizes of a particular species (say 1/4" and 1/2") are for sale, always go for the smaller ones. They're most likely to come from the same egg sac. The smaller ones will most likely be females since females grow a lot slower. The larger ones for sale are probably skewed male.

Maybe the sellers you're buying from have found a way to sex smaller sized tarantulas, and are keeping the females for themselves.

I haven't noticed a large male to female ratio myself, however, I don't buy multiple slings. I typically buy one sling of the species I want of the smallest size they offer. I think I'm only sitting on one male brachypelma boehmei right now and everything else I have is female.

Males wander, which females tend not to do, therefore males are significantly more vulnerable to predators, requiring a higher number.

auskie said:

Your results could be skewed if you're buying the larger options online.

If different sizes of a particular species (say 1/4" and 1/2") are for sale, always go for the smaller ones. They're most likely to come from the same egg sac. The smaller ones will most likely be females since females grow a lot slower. The larger ones for sale are probably skewed male.

Maybe the sellers you're buying from have found a way to sex smaller sized tarantulas, and are keeping the females for themselves.

I haven't noticed a large male to female ratio myself, however, I don't buy multiple slings. I typically buy one sling of the species I want of the smallest size they offer. I think I'm only sitting on one male brachypelma boehmei right now and everything else I have is female.

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I don't think that's entirely true. I have experienced myself that some slings are more well endowed in growth than others, regardless of gender. My theory is that the fastest growing ones are the ones who are most likely to survive in nature. There is always the oddball sling that shoots ahead of its siblings. For example, I have two A. Avics, bought at the same time, fed at the same rate, and both are siblings. The one that turned out to be male is still only 3" in lag span while the one that ended up female is already mature (5"+) and I will be breeding her this week.

On the most part I find that your findings are consistent with what I've largely experienced. This is applicable to a number of Pokie species that I've bred, OBTs, C.darlingi,C.marshalli, P.cambridgei and P.irminia just to name a few. C. fasciatum are the only species that I found that the females of a given sac outnumbered the males.

I too used to believe males molted ahead and often hear it out of an experienced breeder. I've seen this happen MOST of the time through doubles or triplet sacmates, although only ~70%.

I've also witnessed the oddball Klaw described which could sometimes be attributed to early cannibalism. They bumped that first domino a bit early. But that could also have to do with natural selection like mentioned.

On your male issue I don't have much help as I'm sure we've all had our share of bad luck but I've never seen anything quite like THAT. I've heard of certain sacs coming out like described (leaning toward either sex) which could be the result of a number of factors but generally speaking you should expect something close to 50-50 (Even though males may be accepted in the hobby as the greater number). Otherwise I might suspect some cherry picking myself.

Yeah slings can be difficult to sex especially with any guarantee. But if you had a few to compare, certain species can be done with ease, even without magnification. If not shooting for 1i/2i your best may be a big name importer on your next batch??

Yeah I guess your right I had WAY better luck on bigger dealers, not so much otherwise.
Only one small seller gave me a good deal on the pinkblooms , which male seems to be another species of something rarer.

I think it is primarily the luck of the draw. Some sacs will have more male than female and vice versa. I've raised multiple groups of same sac slings with varying results. Males do mature faster than females, but do not necessarily grow faster or bigger than their female sac mates. I've had males from the same sac grow at different rates and mature at significantly different sizes. I've also had a few females from different groups consistently be the largest and fastest growing of their siblings, both male and female. There is no rhyme nor reason. For the most part, ime , spiders kept under the same husbandry tend to grow at comparable rates up until the males mature. In some species, the males mature at a ridiculously young age and/or small size. I don't think there is anyone in the hobby who can accurately sex quarter inch slings such that they keep all the females to themselves and sell all the males. However, when you see folks selling "unsexed" 3 and 4 inch juveniles, that raises a red flag. Although it is possible to never get an intact molt from some individuals to be able to molt confirm the sex.

Formerphobe said:

I don't think there is anyone in the hobby who can accurately sex quarter inch slings such that they keep all the females to themselves and sell all the males. However, when you see folks selling "unsexed" 3 and 4 inch juveniles, that raises a red flag. Although it is possible to never get an intact molt from some individuals to be able to molt confirm the sex.

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Right I did notice where he's added in that "all = quarter inch," only I haven't seen too many .25" poec. Just assumed it was a bit exaggerated and we were talking about slings?? Not sure where a "sling" stops but I feel 1.5" is where some spiders could be interpreted even if it may not be 100% accurate. 3" with exuvium could later be confirmed.

It is mostly luck but reguardless of size there's no argument that there are those who weed out their slings juvies etc when possible. Which I suppose isn't as low as labeling it female without "guaranteed" or screw it let's add the guaranty but keep it vague or not back it up. Aint right but it happens.

90% is a pretty extreme ratio. Lately I've been thinking about temps pokies are incubated. There are quite a few reports of 100 fertilized embryos with half developing. A current sac of mine had been kept at a consistent 80- 82 f which yielded only 27 ewl which are now a few weeks into n2 phase. Decided to drop to 70-75 to see what could be done about the rest those eggs. Days later legs began to form. It may be common to have a wide range for stages in this genus but theres weeks here with nothing inbetween. A buddy of mine had a sac of ornatas not too long ago. I remember him mentioning how weird it was that they all seemed to be coming out female. Even though many people probably don't hold on to large portions of their projects, if any part of this genus might be temp sex dependent I figured it would have been discovered awhile back and never by me, an amateur breeder. Just a thought really.

klawfran3 said:

I don't think that's entirely true. I have experienced myself that some slings are more well endowed in growth than others, regardless of gender. My theory is that the fastest growing ones are the ones who are most likely to survive in nature. There is always the oddball sling that shoots ahead of its siblings. For example, I have two A. Avics, bought at the same time, fed at the same rate, and both are siblings. The one that turned out to be male is still only 3" in lag span while the one that ended up female is already mature (5"+) and I will be breeding her this week.

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I bought 3 H. incei slings and they were all kept the same. I done a trade and sent one off, one was growing quicker then the other two, which I figured was a male so I shipped one of the slower growing ones. A few months later, the one I sent matured into a mature male. I was able to sex the other two and turns out, I shipped the only male away!

Yeah And , how many keepers actually keep records? or Male to female ratio of there baby Ts.
so many Ts too hard to keep track of , once you go past 30-50 range.

Biollantefan54 said:

I bought 3 H. incei slings and they were all kept the same. I done a trade and sent one off, I one was growing quicker then the other two, which I figured was a male so I shipped one of the slower growing ones. A few months later, it matured into a mature male. I was able to sex the other two and turns out, I shipped the only male away!

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cold blood said:

Males wander, which females tend not to do, therefore males are significantly more vulnerable to predators, requiring a higher number.

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+1, males have a higher chance of getting killed, which logically would result in more males after time.

cold blood said:

Males wander, which females tend not to do, therefore males are significantly more vulnerable to predators, requiring a higher number.

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For most species. It's dangerous traveling with hungry predators out.

There are some females tend to live in close proximity to each other and one male can safely service multiple females, so a sex ratio in favor of females would be in the best interests of those species.

---------- Post added 06-29-2015 at 05:29 PM ----------

Ultum4Spiderz said:

Yeah And , how many keepers actually keep records? or Male to female ratio of there baby Ts.
so many Ts too hard to keep track of , once you go past 30-50 range.

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We need to look at the big picture; what so-and-so gets as a sex ratio for a handful of slings he bought is too small a sample to be worth anything. What's needed is for entire sacs to be kept and raised until they can be sexed. This needs to be done multiple times for each species. I don't know of it ever being done once.

Maybe If I get a sack I will try raising them all and see. I am trying to breed P regalis right now I love this species.

Poec54 said:

For most species. It's dangerous traveling with hungry predators out.

There are some females tend to live in close proximity to each other and one male can safely service multiple females, so a sex ratio in favor of females would be in the best interests of those species.

---------- Post added 06-29-2015 at 05:29 PM ----------




We need to look at the big picture; what so-and-so gets as a sex ratio for a handful of slings he bought is too small a sample to be worth anything. What's needed is for entire sacs to be kept and raised until they can be sexed. This needs to be done multiple times for each species. I don't know of it ever being done once.

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Ultum4Spiderz said:

Yeah And , how many keepers actually keep records? or Male to female ratio of there baby Ts.
so many Ts too hard to keep track of , once you go past 30-50 range.

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I keep meticulous records on every t I've ever owned. There have been several occasions where I thought I knew what I had based on markedly different growth rates...turns out its pretty random if growth rates are what you are going by.

2 P. cams, one ate like a beast, grew like a weed, the other fasted constantly, hid all the time and molted with less frequency. Turns out the fast growing big eater, was the female, the stubborn eater/molter, despite fewer molts, matured male after about 13 months.

3 P. fasciata, one was very reclusive, grew slower and appeared lighter in color. One grew like a weed...the other was the slowest grower...all 3 varied greatly in growth...yet all 3 turned out male.

I had 2 P. irminia, again, the faster growing, better eating specimen was, in fact, the female.

5 C. marshalli slings, one of them grew sooooo much faster than the other 4 that I was convinced it was a male...wrong again....it turned out to be the ONLY female of the 5....the smallest btw, is the smallest by far, yet its a confirmed male. All 5 ate extremely well, and molted at a very similar pace.

There's other examples going the opposite way, the way one may expect, where the males out grow the females. Guessing by size is just that, a guess....you may guess right, you may guess wrong.

Many other examples have shown a male and female growing at near identical paces.

Ultum4Spiderz said:

Yeah And , how many keepers actually keep records? or Male to female ratio of there baby Ts.
so many Ts too hard to keep track of , once you go past 30-50 range.

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I keep detailed records on all of my tarantulas. I currently have about 80, plus "inventory".

To get a proper answer to male to female ratio you need to deal with way higher numbers than anyone in this hobby does. If you flip a coin 10 times or even 500 times for that matter, you are likely to get an uneven ratio between crown and denomination. You need to do it several thousand times to get a statistically significant number, so I doubt we´ll ever find out the true male to female ratio when it comes to Ts.

Good job coldblood .,Formerphobe. I hope more keepers will follow suit and keep rack or growth. T hobby is still very young.

Little is known about Ts ,did rick west retire? He was cool
too bad arachnologist pay sucks , anyone experienced on this forum could be an expert.

Ultum4Spiderz said:

Good job coldblood .,Formerphobe. I hope more keepers will follow suit and keep rack or growth. T hobby is still very young.

Little is known about Ts ,did rick west retire? He was cool
too bad arachnologist pay sucks , anyone experienced on this forum could be an expert.

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Rick has not retired, he still identifies new Ts, including one very recently.

Cool Great news!

viper69 said:

Rick has not retired, he still identifies new Ts, including one very recently.

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