Tiny Mygalomorphae (USA Natives)

[cacoseraph]

Tiny Mygalomorphae (USA Natives)

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The recent post on the Microhexura montivaga (Spruce-fir moss spider) ( http://www.arachnoboards.com/ab/showthread.php?t=117703 ) has gotten me thinking about tiny mygs again.


I was wondering what the smallest mygs in the USA were?


I think maybe Hexurella might be small? obviously Microhexura is pretty tiny.

What are the other small ones out there? (bonus points for being in southern california)

[Lelle]

Antrodiaetus sp. are no giants

[cacoseraph]

nice, i will look into them. thanks

[cacoseraph]

Hexurella rupicola makes lenticular egg cases that are 1.5-2mm across and contain 4-7 eggs!

i think this might be one of the smallest mygs in the united states

adult female total bodylenth, including chelicerae is 4.5mm!!!!!!
this spider probably has a DLS of under 1cm!!!!



Megahexura fulva total bodylength of mature female (including chelicerae) is 18mm. carapace is 5.6mm long and 4.7mm wide
(in Claremont, Glendora, Los Angeles, Murietta, Idylwild, and many many more places! )




both of these species can be found in Murietta, CA! anyone up for a trip?!


http://digitallibrary.amnh.org/dspac...25/1/N2687.pdf

[Christian Elowsky]

Nice bit of digging Andrew. If you do find any, please share the pics here! At 4.5 mm they'll just about jump up and bite your nose off! Sheesh. It seems to me looking for these would be like that scene in "Honey I blew up the Kids" with goggles and all!

[cacoseraph]

well, the paper cited is very informative... it has a bit of refernce to where the spiders are found, microhabitat-wise at each locality

it is still frightfully close to the proverbial needle in a haystack though!

i shall enlist the aid of BugBoy... a scabies in his own right and son of one of our officers... he finds really cool stuff EVERYWHERE we go.


the really crummy thing... i *might* have found one of these tiny species the very first time i went bug hunting... and killed it from bad husbandry. i had never kept spiderlings or anything (and they are very much the size of normal tarantula spiderlings) and most likely dessicated it to death

happily the paper leads me to think that Megahexura fulva is VERY common and Hexurella rupicola (incidenitly that names means Little Hexura Rock Inhabitant (the paper is VERY informative!)) is by no means rare
H. rupicola can be found in Murrieta, Riverside County, CA; Johnson Canyon and Lower Otay Lake, San Diego Couny, CA. DANG! i love living in CA!!! Those locations are probably like 100 miles appart so i suspect the range is fairly large

[Christian Elowsky]

I wonder how much genetic isolation is going on in those populations across that range?

Hmm... sounds like a solid thesis to me with some additional work, such as adding a few more species. I wonder if enough isolation has occurred to make up a few species thought the range, it's not like these are going to balloon or walk all that distance!

[cacoseraph]

Originally Posted by Christian Elowsky

I wonder how much genetic isolation is going on in those populations across that range?

Hmm... sounds like a solid thesis to me with some additional work, such as adding a few more species. I wonder if enough isolation has occurred to make up a few species thought the range, it's not like these are going to balloon or walk all that distance!

oh gods i hope not. it will make me have to treat these like local apomastus (with cryptic species that are found syntopically i am trying to convince everyone to line breed until we can do some gene analysis (like that is likely to happen and if so, like it is likely we will have the spiders afterwards))

but if any myg would balloon it would be these... the babies are going to be frightfully small!

[wburke17]

Originally Posted by cacoseraph

i shall enlist the aid of BugBoy... a scabies in his own right and son of one of our officers... he finds really cool stuff EVERYWHERE we go.

You know Dylan(BugBoy) is always up for a challenge

[cacoseraph]

i am making a digestion of info available on Hexurella rupicola here:
http://scabies.myfreeforum.org/about1022.html