It’s derby time and the competition is fierce. But anglers aren’t the only ones out and about on the water; there is another land animal that likes to spend its time near water. Lucky for those that fish, this beast has a preference for fresh water. I, for one, would be a bit disturbed to find myself next to a fishing spider, which is more or less an eight-legged trawler.
No pole or entry fee is necessary for the fishing spider. It can capture and eat small fish and even little tadpoles, although it is more likely that this spider is fishing for caddisflies, mayflies, and other aquatic insects.
Nor would this arachnid want to win the derby boat, since it doesn’t need it — fishing spiders can both walk on water and go below the surface to get their prey. Even more miraculous is that the fishing spider can stay underwater for up to one hour! How they do will blow you out of the water.
It is actually not a skill, but a condition called hydrophobia; or, literally, fear of water. In this case it is not psychosomatic, but rather it is centered on the legs. This spider’s extremities are tipped with a fluid that is hydrophobic, or repels water, so this spider can skim across the surface of the water like a water strider.
Fishing spiders, unlike anglers, don’t need a life jacket either. The hairs on its abdomen trap an air bubble so that even while underwater, it can breathe. Oxygen can be obtained and carbon dioxide can be emitted into this bubble, which allows the fishing spider to spend time underwater.
While we don’t allow fishing at Felix Neck, this water-lover showed up the other day. It came to us, as so many creatures do, not by its own eight feet but in a container (in this case a Vlasic pickle jar) in a brown paper bag. It was accompanied by an adult who wanted to know what it is and how to get rid of it. These types of inquiries make my day, since I love an identification challenge.
My first guess was a wolf spider, but this would have been a really large one. The report was that it was found on a child’s floating toy in a swimming pool. Hmmm. With the help of a spider guide, we confirmed that it was a fishing spider, a hairy variety of spider that can reach up to three inches in legspan. Just to be sure, I cross checked this species in Allan Keith’s and Stephen Spongberg’s book, Island Life — a catalog of the biodiversity on and around the Vineyard, which verified the existence of one species of fishing spider, Dolomedes scriptus, on the Island.
Nowhere in the literature is it mentioned that fishing spiders have a preference for hanging out on a child’s floating toys, but this species tends to do things its own way. Fishing spiders do not spin traditional webs; instead they use their silk to create a web case to hold their eggs. The package is carried in the spider’s chelicerae (jaws), leading to an alias, the nursery web spider. The eggs mature for one week before they leave their mother and venture out into the world to seek their own fishing hole.
After identification, the fishing spider in question was set free. He was luckier than many of the fish at derby time; he was destined to be catch and release.
Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.