Take a look at this revisited specimen...



Working from known specimens it is possible, though, to sometimes acquire a certain familiarity for a species, even when one can't be entirely certain. Here, I think I see a certain typical fatness or roundness of the abdomen and possibly a more golden color than one see in T. zebra... The difference is subtle, but possibly distinguishable? We'll have to wait to see if a couple more turn up.

-K

> The difference is subtle, but possibly distinguishable?

Speaking for myself, I can't see a difference. Take a look at this T. zebra, identified by the epigyne:


The general appearance, including the shape of the abdomen and the color, looks the same to me. Subtle roundeness in one versus another might only be the difference between a meal or two, or camera angle.

I'd also like to see more T. sabulosus specimens. Unless some very distinctive habitus feature becomes apparent, though, I'd say the only reliable way of telling females of the two species apart will be by the epigyne. Maybe such a feature is mentioned in the literature? Kaston (1981) compares the two species, but doesn't mention any reliable habitus differences. Anyway, let me know if anything turns up in your reading. You're far more up on the literature than I am. :)

T. sabulosus is also found in Alberta, so I will be double-checking the "zebras" I find next spring, just in case. So far, though, all of the epigynes I've looked at have been T. zebra. I hope I find one that isn't. :)

Yes, John, I have to admit you are right. Perhaps I was being too optimistic. Well, let's wait until we've seen a few more specimens of both species and then perhaps we'll see a difference (or not).