possible to identify gender when 1 inch from physical appearance

[friendttyy]

is it possible to identify a gender of a T when 1' since the abdomen is longer than body

 

[rob0t]

No, not by the size of the abdomen.

 

[friendttyy]

thanks i was worried all would be males

 

[Spiderkid]

Don't worry, there's a 50% chance it'll be female...you're just gonna have to wait like the rest of us

 

[Poec54]

Don't worry, there's a 50% chance it'll be female...you're just gonna have to wait like the rest of us

Because 50% is the sex ratio of humans, doesn't mean it's that way with spiders, and certainly not across-the-board with tarantulas. Some species are notorious for males being scarce, others seem to have a strong majority of males. They're evolved sex ratios based on their specific climates, geography, predators, distance between individuals, etc. Those of which males travel long distances would seem to be likely candidates to have a higher ratio of males, as some willl perish on their journey, and unmated females is not good for a species survival. Others species live in groups with burrows a few feet apart, and one male can easily service multiple females; a 50/50 ratio is overkill. Some species have several generations living with an adult female; what happen when her sons mature? Poecilotheria may share holes in retreats, adult males and females can live together for weeks, allowing the male a longer life, and more opportunities to impregnate other females. There's so many adaptations to a wide variety of habitats, that you can't assume what any species sex ratio is unless you have more to go on. It's a key piece of their survival strategy, as is how many eggs per sac and the size of the hatchlings. All of this has been fined-tuned over thousands of years for each species.

 

[EightLeggedFreaks]

Because 50% is the sex ratio of humans, doesn't mean it's that way with spiders, and certainly not across-the-board with tarantulas. Some species are notorious for males being scarce, others seem to have a strong majority of males. They're evolved sex ratios based on their specific climates, geography, predators, distance between individuals, etc. Those of which males travel long distances would seem to be likely candidates to have a higher ratio of males, as some willl perish on their journey, and unmated females is not good for a species survival. Others species live in groups with burrows a few feet apart, and one male can easily service multiple females; a 50/50 ratio is overkill. Some species have several generations living with an adult female; what happen when her sons mature? Poecilotheria may share holes in retreats, adult males and females can live together for weeks, allowing the male a longer life, and more opportunities to impregnate other females. There's so many adaptations to a wide variety of habitats, that you can't assume what any species sex ratio is unless you have more to go on. It's a key piece of their survival strategy, as is how many eggs per sac and the size of the hatchlings. All of this has been fined-tuned over thousands of years for each species.

It's probably that they read somewhere that they come out 50/50. I read that somewhere, or heard it. But yes, you're 100% correct.

 

[CEC]

I think you both are right. If you flip a coin 100 times it usually doesn't turn out 50/50 but the odds are still 50/50(heads/tails=male/female). I think that might be the confusion.
Odds can be very misleading. As Poec54 mentioned, statistics would be a better guideline or source of chance but unfortunately we do not have a tarantula census.

 

[friendttyy]

i think i should wait like the rest of you

 

[Spiderkid]

Haha I just meant that with the limited number of slings I've raised, the ratio of males to females has always been fairly constant, around 50:50. You're completely right though, for us to make any conclusions that are 100% certain, we'll have to raise thousands of slings from different sacs, under carefully controlled conditions.

 

[friendttyy]

thanks for all the input

 

[prairiepanda]

is it possible to identify a gender of a T when 1' since the abdomen is longer than body

The abdomen size doesn't really matter at any stage of life; the body shapes of each gender are generalizations and don't always apply. But at 1" you should be able to sex it ventrally if you practice with some photos of similarly sized slings.

 

[friendttyy]

thanks prairiepanda

 

[Neoza]

Because 50% is the sex ratio of humans, doesn't mean it's that way with spiders, and certainly not across-the-board with tarantulas. Some species are notorious for males being scarce, others seem to have a strong majority of males. They're evolved sex ratios based on their specific climates, geography, predators, distance between individuals, etc. Those of which males travel long distances would seem to be likely candidates to have a higher ratio of males, as some willl perish on their journey, and unmated females is not good for a species survival. Others species live in groups with burrows a few feet apart, and one male can easily service multiple females; a 50/50 ratio is overkill. Some species have several generations living with an adult female; what happen when her sons mature? Poecilotheria may share holes in retreats, adult males and females can live together for weeks, allowing the male a longer life, and more opportunities to impregnate other females. There's so many adaptations to a wide variety of habitats, that you can't assume what any species sex ratio is unless you have more to go on. It's a key piece of their survival strategy, as is how many eggs per sac and the size of the hatchlings. All of this has been fined-tuned over thousands of years for each species.

its not 50% chance by humans

 

[Poec54]

its not 50% chance by humans

Not sure what you're saying, but when humans are born (worldwide), there's a 3 percentage point higher ratio of males. By the time they reach age 20 or so, the sex ratios are equal. This has evolved over hundreds of thousands of years to compensate for the additional risks young males take in establishing their hierarchy in the group and defining their territory.

 

[korg]

thanks i was worried all would be males

Don't worry... you could just feed them a few big meals and then they would all be "female."

All of this has been fined-tuned over thousands of years for each species.

You are right about the sex ratio for different species of tarantulas not necessarily being 1:1 for various reasons, but this seems like a bit of an oversimplification. There are factors (genetic drift, etc) that can actually cause populations to evolve in ways that make survival more difficult... the process isn't necessarily progressive or all about "fine tuning."