Trechaleid Spider with Young

July 19th, 2010 - 10:44 PM | Filed under Featured Creatures | No comments

The first thing I photographed after arriving in Caraça Natural Park was this hunting spider, found wandering in an unpaved parking area.

Trechaleid Spider with Young | January 25, 2010 | Caraça Natural Park, Minas Gerais, Brazil

Up until I started preparing to write this post, I figured this was a wolf spider. After reading to learn more about the parenting behavior shown here, I’m now convinced it is instead a species in the family Trechaleidae. What first tipped me off was a similar photograph in this little book:

Spiders (Collins Gem)
by Paul Hillyard

Several identifying characteristics are mentioned for the particular species pictured. After some online searching, most appear to be shared by other species of the family.

The middle eyes are smaller than those of a wolf spider. Compare the image below with a wikipedia image of a wolf spider.

Detail of eyes, smaller than those of a wolf spider

Every time I looked at certain images, something struck me as odd about the legs. Indeed, something mentioned by the book above is “carved” leg endings, which I assume is a misprint for “curved”.

Curved tarsus

Trechaleids also have a circular carapace, here being overrun by spiderlings:

Circular carapace viewed from above

Whereas wolf spider young are carried on the mother’s back after emerging, Trechaleids carry their young on the egg sac. Here’s a closeup of the spiderlings on the egg sac. The lighter colored area at the bottom has some shed skins. In some of my photos, it looks like it might be an emergence point.

Spiderlings and shed skins on egg sac

As you can see in the initial photo above, the spiderlings were nicely grouped on the egg sac. Then this ant somehow climbed aboard and started wreaking havoc. That’s why there are spiderlings scattered over the mother’s carapace in some of these photos.

Inconvenient ant

Lastly, here’s a not so great image of the entire spider (and the marauding ant).

Entire spider

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