Wild Fact #499 – Ewwwww – Dock Spider

Wild Fact #499 – Ewwwww – Dock Spider

Dock Spider

Female with Babies - Photo by N.V?lavi?ien? (Wikimedia)

Now I know a lot of my readers will not be too pleased with today’s Wild Fact but while visiting my parents place this past weekend, I learned that they are in the midst of quite the battle with the infamous Dock Spider. Apparently they keep finding nests with hundreds of baby spiders around their deck and dock. I am not going to lie, this even creeps me out. These spiders are huge and the thought of hundreds of baby spiders roaming around the house…….ewww. If you are not familiar with the Dock Spider, it may just be that you call them something else. These wonderful “little” critters are also known as Fishing Spiders, Raft Spiders and Wharf Spiders. Let’s see if my parents need to be worried about being taken over by these bugs.

Almost all Dock Spiders are semi-aquatic with the exception of one odd ball spider that can be found in Southwestern USA that prefers to live in trees. Talk about being the black sheep (or spider) in the family. There are over 100 species of Fishing Spiders in the world and almost all of them hunt in a similar fashion. They wait patiently by the waters edge until they detect the faint ripples of an innocent insect passing by and then at the last moment the deadly spider runs across the water to subdue their victim with the claws on the front legs. Once they have the prey in their clutches it is lights out for the insect as the Dock Spider injects the life-sucking venom into the helpless animal. Whoa… wait a minute! Dock Spiders have venom? Should my parents be selling their house? Nah, their venom is pretty much harmless to humans (I still don’t recommend testing this theory though).

Fishing Spider

Female Guarding her Nursery - Photo by Bryce McQuillan (Wikimedia)

So what is with all the eggs laying around everywhere in Northern Ontario right now? Well, the type of Dock Spider found in these parts have an interesting breeding behaviour. The females will typically lay about 500 eggs (Yes, I said 500) but before setting up the nursery, which is usually composed of leaves or in rock crevices (and apparently on decks and docks), they will carry their egg sacs in their fangs for up to 3 weeks. Usually the female Dock Spider will live long enough to lay 2 or even 3 sets of egg sacs before dying. I have a hunch this rule doesn’t apply to the ones my family keeps finding.

Dock Spider Fast Fact – I know this fact is running a little longer but I thought you would like this interesting adaptation. When a Dock Spider is threatened they will typically submerge themselves in the water. Once underwater tiny air bubbles will gather on the spiders hairs allowing them to remain submerged for 10 to 15 minutes. That is pretty cool, eh?

Okay, I hope you enjoyed our creepy Wild Fact.  See you tomorrow!

2 Comments

  1. Avatar
    mom August 09, 2011

    Ewww…totally gross. If they make it in the house….(which the decks and docks are far enough way)….the house is gone. sorry Nathan but these little guys I will keep destroying.

  2. Avatar
    Mary Lou November 11, 2011

    Just to let you know – I was bitten by a dock spider through my bathing suit last July at the cottage, went into anaphylactic shock and just made it to hospital in time. IV epinephrine and fluids and an overnight stay and I was fine. The fang marks were very visible on my hip with a 7inch area of redness all around. I now must carry an epipen and benadryl. It may not have that effect on everyone, but I don’t recommend taking a chance.

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