Invertebrates

See our handy guide to critters found in local homes and our Central Coast Butterfly FAQ. Browse the insects and other terrestrial arthropods we’ve identified. Check out local marine invertebrates, particularly bivalve mollusks and intertidal organisms.

What is this arachnid?

Saw this on my front door today, is there an arachnologist you know who can identify it? It was a bigger spider than I typically see around here roughly the size of the largest wolf spiders I see here. To give you an idea the body was as big as my pinky fingernail and if you include the outstretched legs about the size of a silver half dollar.

Hans, Newbury Park, CA - May 6, 2022

Curator Response

Hi Hans,

Thanks for sending us your arachnid. That looks like a black harvestman with some mite parasites. Harvestmen are non-spider arachnids in the order Opiliones. You can often quickly tell a harvestman from a spider by the way the body segments appear fused. In spiders you can see the distinct two segments, but on a harvestman the cephalothorax and the abdomen look like just one connected segment.

I don't know the species pictured in your photo, but it's very similar to this one, so could be in the Protolophus genus.

Stay curious,

Collection Associate Jennifer Maupin, Ph.D.