Color variation in Monocentropus balfouri

[Haksilence]

Hey all,
Out of my 3 M balfouri females (all of which are roughly the same size) all 3 have slightly different coloration.
More specifically abdominal coloration. My largest female and the second largest are the most notable difference with the largest having a very dark colored abdomen with the blue undercoat while the second largest is solid tan colored on the abdomen with zero visible blue.

Has anyone else noted this as well, could there possibly be a variety of M balfouri CF's?

Pictures when I get back from vacation.

 

[KezyGLA]

M. balfouri will vary in colour with many factors. Age, sex and proximity to moult being the main factors in colour.

In short, no. There isnt colourforms, but each specimen will vary slightly. Most differences noticed are in brightness of blue on legs and amount of blue sheen on carapace. I have noticed the abdomens going dark, some even orangish but this is mostly related to moult cycle.

 

[Haksilence]

The thing is the two females in question, last molted a week apart, with one being completely tan with no sign of blue on the abdomen, and the other maintaining that blue color throughout

 

[elportoed]

The one with the tint of blue is defective, you should send her to me, so she can be disposed of properly.... Ha ha...
I have similar experience with the coloration.

 

[Blue Jaye]

Are you sure the one showing blue on the abdomen is a female? I usually only see blue on the abdomen on males either a molt before they mature or at maturity. I have an army of balfouri. Several communals and many single individuals. And have yet to see a female with this coloration. But that may just be my personal experience. Other genetic line may show more blue in females.

 

[viper69]

In older posts here, before they were popular, those with more T, particularly on the legs approaching the body were thought to be males if I recall correctly.

 

[KezyGLA]

In older posts here, before they were popular, those with more T, particularly on the legs approaching the body were thought to be males if I recall correctly.

Yeah. Penultimate males can be spotted easily due to the amount of blue. Stretches up the femurs and carapace sometimes darkens too

 

[viper69]

Yep, it's quite striking. In those posts and the pics I've seen of this species, I haven't noticed much difference of the abdomen. Mine are small, just reached blue legs 2 months ago. Now that they are larger, they sure are ready to put up a threat pose though from time to time, amazing what a few inches does to a T!

Yeah. Penultimate males can be spotted easily due to the amount of blue. Stretches up the femurs and carapace sometimes darkens too

 

[Haksilence]

Are you sure the one showing blue on the abdomen is a female? I usually only see blue on the abdomen on males either a molt before they mature or at maturity. I have an army of balfouri. Several communals and many single individuals. And have yet to see a female with this coloration. But that may just be my personal experience. Other genetic line may show more blue in females.

I'm not positive, but I think it's female, mostly from the 70+ slings running around in her enclosure from the sac she laid

This is an older photo of the female, after her most recent molt the blue on her abdomen more matches the hue of her legs and the carapace has darkened and become more blue as well

Compared to this female, the other has a much lighter carapace and the typical full tan colored abdomen, zero blue at all on the abdomen

 

[KezyGLA]

Shes a very nice specimen. Do you have a photo of her now? I would like to see the blue abdomen. Seems very unique

 

[viper69]

Same here BJ, I'd like to see as well.

 

[Haksilence]

I'm on vacation currently, which is why I don't have a photo of the other female for comparison. But once I'm home (the 5th) I'll have current photos of each

 

[Blue Jaye]

@Haksilence well dropping a sac is definitely a sure sign of a female lol. And like I said it's just been my experience. I've paired one female with two different males in the last few years. With three sacs fro those pairings.One male being almost completely blue and the other a typical looking male. None of my females show blue on the abdomen. It's nice to see there are different color variations in females other the the tan or dark brown abdomen.

 

[Haksilence]

Yeah I'm going to keep the slings from each female separate to see if the trait is a dominant trait line and to see if it can be replicated in the next generation

 

[Haksilence]

Dark form

Normal form

both photos were taken with identical lighting without flash.

the dark form, besides the very apparent blue/dark coloring on the abdomen, the blue on the legs appear to run farther up the femur and seem to be a brighter blue. (color intensity is most likely do to molt cycle variation though)

the dark form just lard a sac and is currently brooding over about 60 or so (at least thats as many as ive counted on the surface at any given time) slings. im going to keep these separated and labeled differently from my other females slings and see if the offspring retain this coloration so see if its able to be isolated and reproduced. Im also looking to see if both forms come from the same sac.

 

[Haksilence]

also the light form appears to have black spinnerets while dark has blue

 

[Blue Jaye]

Here's some pics of my communal plus a couple of my original adult female who is also in the communal. All are her offspring. All are female.

 

[Angel Minkov]

Color variation is completely normal. No need to delve into it.

 

[Haksilence]

Here's some pics of my communal plus a couple of my original adult female who is also in the communal. All are her offspring. All are female. View attachment 251360 View attachment 251361 View attachment 251362 View attachment 251364 View attachment 251365

Very interesting. I see some of the tan, the orange, and the darker ones. Now I'm wondering what drives the variation

 

[miss moxie]

It's more than plausible that M. balfouri is a species that displays polymorphism. They're still on the new side, after all, and are still on the pricy side so they aren't something most keepers have in their collection which means there aren't as many specimens or keepers to make comparisons and note definitive differences. For example we're aware that there are a slew of OBT color forms, but OBTs are so popular and cheap and have been around a lot longer than M. balfouri so a lot more people have had a lot more time to find these color forms.

This is definitely interesting though, and probably a thread that should get bumped once in a while to get more people contributing color variants from their own specimens. I'd add some but my balfouri are still small, 2".