Fishing spiders are a specific species of spiders that live near bodies of water. The spiders can stretch out as long as 70 millimeters, making them very large and intimidating looking. Many people fear fishing spiders for this reason. After all, they are kind of scary looking.
With that being said, fishing spiders are harmless. Fishing Spiders are not poisonous. Although they can bite and deliver poison, their poison is not dangerous unless you are specifically allergic to it. Most people agree that fishing spider bites are no more severe than a bee sting.
Read on to find out more.
Fishing Spiders: A Complete Overview
Fishing spiders are members of the Nursery-Web family or Pisauridae family. This means that they are semi-aquatic and hunt on land and water. Their large and hairy body structures can distinguish them. Their bodies are decorated with black, brown, gray, and white patterns.
Often, fishing spiders are mistaken for wolf spiders, but their bodies are typically slimmer. Like all spiders, they have two body segments, eight legs, fangs, and eight eyes. They differ from most spiders in how they can walk and hunt on water.
Where They Get Their Name
Fishing spiders get their name from their food sources and hunting action. The spiders often hang out around the edge of bodies of water because they can attack insects on land, but they can also sink their bodies underwater to hunt small fish and tadpoles.
The fact that these spiders can go underwater is due to their bristly hairs. The hairs on their body trap air bubbles that they can use to breathe while underwater. As a result, fishing spiders can wait underwater until their prey comes by.
Their hair is so effective at trapping air bubbles that they can stay underwater for more than 30 minutes at a time. So, they wait there until an unsuspecting insect lands on the water or a fish swims by.
Walking on Water
Do you remember when you were a kid, and you would try to walk on water as you saw in the cartoons? You were probably disappointed every time to find out that you couldn’t do it.
Fishing spiders tell a different story. They can walk on water. Well, sort of. Though they often hold onto vegetation at the edge of the water, the spiders can run over the water to attack their prey.
To understand how fishing spiders can do this, we have to have a little physics lesson. All water has a surface tension. The surface tension is caused by water molecules attracting to each other more than they attract the air. Though we can’t see it, the surface tension creates a rubbery layer on the water.
To us, surface tension is very weak. We can effortlessly break through the surface tension. Similarly, we can throw a rock in the water and watch it sink all the way to the bottom. Fishing spiders, however, are light enough that the surface tension supports their weight.
Fishing spiders have hydrophobic short hairs on their legs that repel the water from their bodies. This means they do not get wet and can use surface tension to move on the water.
They use surface tension by creating dimpled pits in the water’s surface with their legs. The surface tension then pushes the water back together, allowing the fishing spider to remain on top of the water.
How They Move
Interestingly, the surface tension only holds the fishing spider above the water – it can’t help them move. If the spiders move their feet, they sink. It is the slipperiness of the water that helps them move. This makes it look like the spider is running, even though it is not.
Fishing spiders move on the water by rowing. This is the most popular moving technique of fishing spiders because it is easier on their bodies.
They use the pits created by their feet to have a rowing motion. The pit retracts whenever the fishing spider moves its foot from front to back. This allows the pit to force the spider forward. All the while, the fishing spider keeps the front and rear legs motionless so that it can stay above the water.
Another movement strategy that fishing spiders use is called galloping. To go faster than 1 meter per second, they choose to gallop. This technique is extremely difficult for fishing spiders, and they only do it to catch prey or escape from danger.
How they gallop is by raising their legs so that they are almost vertical. Then, they immerse their legs in the water. After the spider pushes its legs down and back, the water retracts, pushing the spider forward. The forward and up motion from the water prevents the spider from sinking.
To get somewhere a little faster without the need of a gallop, fishing spiders sail. Sailing is whenever the spider lifts his two front legs towards the wind to allow it to push the body like a sailboat. Since the water is so slippery, even the slightest wind can push the spider forward.
How They Hunt
Fishing spiders wait at the edge of a stream or still water while they are hunting. This allows them to hunt on water or on land.
The predator looks for ripples on the water to detect prey. Once the ripples are detected, the fishing spider runs across the water’s surface to catch the prey with its forelegs. The spider then bites the prey and injects venom so it can kill and eat.
Fishing spiders place their back legs on land and their front legs on the water. Because of how sensitive their hairs are, fishing spiders can calculate the prey’s direction and their distance to it. Fishing spiders will sometimes use silk ropes, so they don’t go past the insect.
Although fishing spiders primarily hunt on water, they hunt on land too. In fact, fishing spiders will hunt just about anything they can get their fangs on. With that being said, they run away from animals much bigger than themselves, like humans.
Fishing spiders almost exclusively hunt at night. The night time is when their main predators, birds, are asleep. This allows them to safely hunt.
The Lifespan of a Fishing Spider
Like all spiders, fishing spiders are born in eggs and hatch as small adults. The females lay their eggs on a silky baseplate. They then wrap the eggs into a ball-shaped aggregate.
Once the ball is made, the females carry the egg ball in their mouth until they find a safe place for them to hatch. Whenever they find a safe place, the females build a web, attach the ball to it, and cover the ball until it hatches.
Whenever the eggs hatch, hundreds of little spiders may come out. Unlike humans, spiders are basically born as small adults. They can live on their own immediately after being hatched. As they grow, they shed their skin.
In the wild, snakes and birds are the fishing spider’s biggest predator. Sometimes, dragonflies will hunt the young spiders, too.
There are also parasitic wasp species that feed on the fishing spider. They sting the spider, paralyze it, and lay eggs in its body. Once the eggs hatch, the baby wasps eat the spider from the inside out. Some wasps will even go under the water surface to sting the spider.
A Fishing Spider Bite
Like all spiders, fishing spiders have fangs that they use to bite their prey. Whenever they bite their prey, venom is released. This venom is deadly to the fishing spider’s insect or fish victims. However, fishing spider bites are harmless to humans, often no more severe than a bee sting.
Fishing spiders are unlikely to bite humans in general. Normally, they run away from humans without ever having the opportunity even to bite one.
Fishing Spider Bite Symptoms
Nonetheless, a fishing spider can bite you. Most reports state that a fishing spider bite is followed by immediate burning pain at the sight of a bite. This pain is similar to the pain from a bee sting. The area will then become red with minor local tissue necrosis.
The only time you would have a severe reaction to a fishing spider bite is if you are sensitive to specific spider venoms. If you react more severe than a bee sting, contact a health provider immediately. This means that you are allergic to the specific spider venom.
Fishing Spiders in Pools
Since fishing spiders love bodies of water, don’t be surprised if you find one in your pool. Although the fishing spider is not aggressive to humans and their venom is not harmful, you may want to get rid of them, nonetheless. They are unsightly and a little scary looking.
How to Get Rid of Them
If you want to get rid of your fishing spider friend, you have two choices: you can either relocate the spider or kill it. Here is how to do both:
- Non-Kill: Use a net with small holes to catch the spider. Make sure the holes are small enough so that the spiders do not fall out. Empty the net in an area far away from the pool. During the transportation process, put the spider in a container with holes for airflow.
- Kill: Spray insecticide around the perimeter of your pool line. Chlorpyrifos in liquid concentrate will work effectively. This option uses chemicals to kill the spider. For a safer alternative, you could also sprinkle food-grade diatomaceous earth around the pool and yard. This will effectively break down the spider skeletal system, but it is more natural to the ground and your family.
After getting rid of your fishing spider, put your best foot forward by preventing them from coming back. Even if you effectively get rid of the fishing spiders, they can come back. Below are a few simple tips that you might want to use:
- Relocate Them to a Galaxy Far, Far Away: If you went with the no-kill route, make sure that you relocate them far enough away from your pool that they won’t get back. If you only relocate them a short distance from your pool, they may creep back to the water.
- Avoid Using Lights: Lights often attract spiders in search of prey. Remove any lights from your pool, so that way spiders are not drawn to them.
- Remove Hiding Areas: Spiders are unlikely to stay in areas where they cannot hide. Remove any wood or compost piles near the pool because these are ideal hiding places for many fishing spiders.
Wolf Spider vs Fishing Spider
Many people mistake a fishing spider for a wolf spider. Both spiders look similar, and neither are deadly. You don’t need to have extreme caution if you don’t know what kind of spider you are dealing with. Both types are non-deadly to humans.
If you want to know if you are dealing with a wolf spider or fishing spider, think about where they are located. Fishing spiders are often found around bodies of water, while wolf spiders are almost always found on dry land.
Similarly, you can look at their bodies. Both spiders have similar coloration and size, but wolf spiders tend to be leaner. In other words, if the body of the spider is much thicker, you’re probably dealing with the fishing spider, not a Wolf spider.
Although you might be terrified of a fishing spider if you are an insect, you have no reason to fear them if you are a human. Their bite is rare and no more dangerous than a bee sting. It temporarily hurts, but your body quickly recovers.
Still, fishing spiders deserve respect. Try your best to leave them alone. If they are invading your space, feel free to relocate them, or kill them. If you find them out in nature, try your best to leave them as they are, and respect their hunting area. Though they cannot kill you, leave them be.