Large Fishing Spiders are not an uncommon find in my barn. They are usually found positioned head down on the concrete block wall. When I noticed this female slipping into and out of the gap between the large sliding door and the barn wall, I figured something out of the ordinary must be happening.
I carefully opened the door and found an empty egg case and a mass of young spiderlings.
The female Fishing Spider carries her egg case with her until the eggs are near to hatching. At that point she builds a nursery web and inserts the egg case near its center.
The newly hatched spiders spend about a week living in the protection of the nursery web. During this time they utilize the last of the energy from their eggs, become competent crawlers and increase their size slightly. After their first molt, they leave the web and strike out on their own.
I’m not sure of the lifespan of these spiders, but it must take a female two or three years before she lays a batch of eggs. I may have been seeing the same spider for the last couple of years. With luck, I’ll have the good fortune of meeting some of these spiderlings when they have become adults.