Sling sexing hints

[justanotherTkeeper]

So, I know it is very difficult (if not impossible) to sex slings smaller than 3/4-1" DLS

BUT there are a few indicators the experienced eye can sometimes spot - such as the growth rate. The theory is; when you have say, 2 to 4 (or more) slings from the same egg sac, you likely have some of each - boys and girls. If you monitor their growth, some of these slings will molt more often and grow faster than their siblings, despite providing all the same care, conditions, and feeding routine.

@Thawn139 posted about this once, affectionately deeming it the "S.W.A.G. approach" lol. Basically, the ones molting and growing faster would likely be males, and the slower growing slings are likely females.

Right?

So here's what I'm wondering... I got two 1/2" E. weijenberghi slings couple months ago, both same size and from same seller. I do not know for sure they are from the same sac, but circumstantial evidence says there's a good chance they're siblings. One molted 9/16, and the other molted today 10/30.

Given this is a slow-growing dwarf species, is this not a significant enough gap between molts to guess that today's T is a girl? It's very early to try using this method to make a gender guess, I know, but I can be a stubbornly impatient person lol.

Any opinions or additional information is welcome

 

[The Grym Reaper]

Basically, the ones molting and growing faster would likely be males, and the slower growing slings are likely females.

Right?

Nope, there are far too many factors that affect growth rates

 

[moricollins]

No direct correlation between growth rate and gender. Males can grow faster than females. Females can grow faster than males. No rule about which gender grows faster, even within a single species.

 

[viper69]

So, I know it is very difficult (if not impossible) to sex slings smaller than 3/4-1" DLS

BUT there are a few indicators the experienced eye can sometimes spot - such as the growth rate. The theory is; when you have say, 2 to 4 (or more) slings from the same egg sac, you likely have some of each - boys and girls. If you monitor their growth, some of these slings will molt more often and grow faster than their siblings, despite providing all the same care, conditions, and feeding routine.

@Thawn139 posted about this once, affectionately deeming it the "S.W.A.G. approach" lol. Basically, the ones molting and growing faster would likely be males, and the slower growing slings are likely females.

Right?

So here's what I'm wondering... I got two 1/2" E. weijenberghi slings couple months ago, both same size and from same seller. I do not know for sure they are from the same sac, but circumstantial evidence says there's a good chance they're siblings. One molted 9/16, and the other molted today 10/30.

Given this is a slow-growing dwarf species, is this not a significant enough gap between molts to guess that today's T is a girl? It's very early to try using this method to make a gender guess, I know, but I can be a stubbornly impatient person lol.

Any opinions or additional information is welcome

That SWAG is garbage.

Just wait like everyone else

 

[thatdadlife619]

No direct correlation between growth rate and gender. Males can grow faster than females. Females can grow faster than males. No rule about which gender grows faster, even within a single species.

If there’s never been any direct correlation, why is there so much heavy opinion out there that females ALWAYS grow slower than males? I always keep an open mind in this hobby, I’m just curious why so many keepers believe it to be true

 

[moricollins]

If there’s never been any direct correlation, why is there so much heavy opinion out there that females ALWAYS grow slower than males? I always keep an open mind in this hobby, I’m just curious why so many keepers believe it to be true

Because people will believe whatever they're told...

I have yet to see a scientific paper linking growth rates to gender in tarantulas.

There are lots of anecdotal reports on this forum from people whose females grew faster than males (from people who have 5-10 slings from the same egg sack), and vice versa.

 

[Liquifin]

Other than what kind of species it is, sex or gender of a spider has nothing to do with growth rates. I think people need to understand that every tarantula is a unique specimen just like every person. Not every person grows at the same time or rate and it should also be applied to tarantulas as well.

I think people should be happy enough to enjoy what species they have and not worry about what sex it is. People are too desperate for females these days which many of those keepers completely ignore how rare a male is. Yes, I know a male is not long lived, but just wait until he's mature then you'll see the true value for a male. I see more females for sale than males, so that's saying something.

 

[cold blood]

Basically, the ones molting and growing faster would likely be males, and the slower growing slings are likely females.

Right?

wrong

I see this absolutely false speculation all the time...raise enough slings and you will see the theory holds no water.

In fact, often the opposite is often true with females out pacing males...in fact, i find the slowest growing, runty slings to most often (but not always) end up to be males.

Fact is, some males grow faster than average, others slower, others right in line with norm....and the same can be said with regard to females.

I’m just curious why so many keepers believe it to be true

because it keeps getting repeated, plain and simple....thats how misconceptions get wrongfully accepted....it gets repeated, then it gets assumed to be true.

 

[Vanessa]

If there’s never been any direct correlation, why is there so much heavy opinion out there that females ALWAYS grow slower than males? I always keep an open mind in this hobby, I’m just curious why so many keepers believe it to be true

Because some people really do experience that - they have a small amount of tarantulas and it definitely has been part of their experience that the males grew faster than females. Males can grow faster than females in some cases... just not enough to say that it is a sure bet that you can determine sex by growth rate.
You see that it is not a reliable gauge the more tarantulas that you have of different species. If I looked at my collection, and took some of the most popular species in the hobby - Avicularia avicularia, Grammostola rosea/porteri, Brachypelma - and compared my males and females, my males grew faster. However, if I look at some of my other species - the Thrixopelma, Tliltocatl, a good percentage of my dwarfs, the Bonnetina, the Euathlus, some of the faster growing Grammostola - a good percentage of them had males and females grow at pretty much the same rate and some where the females even grew faster.
It isn't that males don't grow faster than females, because they do in some cases, it's that it is not consistent enough to use growth rate as a reliable sexing tool.

 

[lazarus]

BUT there are a few indicators the experienced eye can sometimes spot - such as the growth rate. The theory is; when you have say, 2 to 4 (or more) slings from the same egg sac, you likely have some of each - boys and girls. If you monitor their growth, some of these slings will molt more often and grow faster than their siblings, despite providing all the same care, conditions, and feeding routine.

This is just a legend in my experience and I usually buy slings in groups of 3/5/8/10. The source for this legend I think is the fact that males reach maturity in fewer molts than females.
But you can sex slings with a microscope, 5th or 6th instars are usually sexable with a fairly affordable microscope.

 

[Smotzer]

I find that sexing them is often a pretty good indicator and thats about it.....

 

[Butterbean83]

This is interesting. I always wondered if the molts can determine gender when under a microscope when Ts are still slings?

 

[Brewser]

Gender refers to Social Characteristics.

 

[Butterbean83]

You know what I mean Determine the sex of the Tarantula slings.

 

[0viWan]

Interesting case study:

2x Brachypelma Klaasi. Presumably sac mates. Recieved at the same size (~1')'.

Those two were pretty much on the same molt cycle with only a few days difference. They also remained the same comperable size after each molt. Last molt was like 1.5 weeks earlier for the confirmed female, which is now ~2.5''. The confirmed male has gained considerably more size with this molt though and is now like 2,75''. I was actually surprised about the size gain in comparison. It is also worth noting, that the male now is remarkably lanky so if you put the two spiders side by side it is very obvious which one is male and which one is female.

 

[sparticus]

You know what I mean Determine the sex of the Tarantula slings.

Yes, with a good microscope and some impressive unfolding/"how did they not rip that??" skills, sex can be determined even on quite small slings. Just takes more skill and patience than most of us have acquired, so we like to guess using stuff liks growth rates. Plus you have to wait for a molt and then hope it's not shredded to get an accurate sex. Lame. Guessing is more fun, and you're about 50% likely to get it right anyway.

I have not seen a difference in size gains between male and female slings, personally. I have had one runty, slow growing sling and he matured out as a tiny male, about a year after his normal growing brother. The female and the "normal" male grew at the same rate.

 

[Butterbean83]

Yes, with a good microscope and some impressive unfolding/"how did they not rip that??" skills, sex can be determined even on quite small slings. Just takes more skill and patience than most of us have acquired, so we like to guess using stuff liks growth rates. Plus you have to wait for a molt and then hope it's not shredded to get an accurate sex. Lame. Guessing is more fun, and you're about 50% likely to get it right anyway.

I have not seen a difference in size gains between male and female slings, personally. I have had one runty, slow growing sling and he matured out as a tiny male, about a year after his normal growing brother. The female and the "normal" male grew at the same rate.

I'll be able to tell with my Harpactira pulchripes because they don't get much past 2" I hear. It's a 3cm Sling at the moment so I'm gonna get another one soon so I have more chance of one being female. Yeah it seems hard enough to keep a molt intact to determine the sex even of an adult Tarantula, none of mine have molted yet.

 

[Ultum4Spiderz]

I'll be able to tell with my Harpactira pulchripes because they don't get much past 2" I hear. It's a 3cm Sling at the moment so I'm gonna get another one soon so I have more chance of one being female. Yeah it seems hard enough to keep a molt intact to determine the sex even of an adult Tarantula, none of mine have molted yet.

My female lp are larger then males all about same age 8-10 years, still waiting for males to hook out but talk about long lived . People used to say they grow lightning fast but in my case nope .

Whats your Lasiodora size ??

well i will be putting that to the test with a friend he is of the same opinion, and feeds them huge meals as well as keeps them warmer than me the spiderlings he got from me are already leagues ahead of the ones i am raising myself, but i do wonder if it will impact their maximum size...

arachnoboards.com

 

[Butterbean83]

My female lp are larger then males all about same age 8-10 years, still waiting for males to hook out but talk about long lived . People used to say they grow lightning fast but in my case nope .

Whats your Lasiodora size ??

well i will be putting that to the test with a friend he is of the same opinion, and feeds them huge meals as well as keeps them warmer than me the spiderlings he got from me are already leagues ahead of the ones i am raising myself, but i do wonder if it will impact their maximum size...

arachnoboards.com

That's awesome in a way that they haven't grown as quick as possible and lived longer, it seems.to be the case with G Rosea and Aphonopelma species, slower growing species live longer. I do hear a lot that LPs grow quickly, some maybe at a medium rate, I guess it's a case of temperature and feeding for the most part but not all, I guess some just have varying genetic growth rates. What temps do you keep them at? I tend to keep all my Ts at 22-25c and turn them down to 19-21c late at night.

I'm in the UK so I couldn't tell you what that is in farenheit. I'd have to look it up. I'm sure you're feeding as regularly as everyone else so I'm guessing some individual LP clutches are different. I don't own an LP though my Ts that should grow the biggest I have an Acanthoscurria Geniculata juvenile female and a Phormictopus Auratus sling. Both of them should get 7-8" I would imagine, that's it the Phormictopus Auratus is a female.

 

[Ultum4Spiderz]

That's awesome in a way that they haven't grown as quick as possible and lived longer, it seems.to be the case with G Rosea and Aphonopelma species, slower growing species live longer. I do hear a lot that LPs grow quickly, some maybe at a medium rate, I guess it's a case of temperature and feeding for the most part but not all, I guess some just have varying genetic growth rates. What temps do you keep them at? I tend to keep all my Ts at 22-25c and turn them down to 19-21c late at night.

I'm in the UK so I couldn't tell you what that is in farenheit. I'd have to look it up. I'm sure you're feeding as regularly as everyone else so I'm guessing some individual LP clutches are different. I don't own an LP though my Ts that should grow the biggest I have an Acanthoscurria Geniculata juvenile female and a Phormictopus Auratus sling. Both of them should get 7-8" I would imagine, that's it the Phormictopus Auratus is a female.

Room temperature around 70-77 . 72-77 during summer /70 winter . And yes regularly fed weekly to monthly depending on abdomen size . Well fed .