The Spider that Lives Underwater

Spiders know no math! Yet they are masterful architects and construct webs with precise geometry. The complexity of the spider web has inspired research for decades. Spiders live in cracks and nooks, and perch atop trees, all with their web-weaving skills. They can even use their webs like a parachute to fly! This technique is called ballooning. As they’ve won areas on land, and somewhat in the air, it might be just wishful thinking to picture spiders living underwater.


Or, maybe some already do?


As the name suggests, diving bell spiders dwell in clean water bodies with aquatic vegetation. Diving bell spiders are 8 mm to 15 mm (0.3 to 0.6 in) long and have a gray or brown body. Their abdomens are covered in hair. They are the only species of spider that can live underwater. Just like their terrestrial counterparts, diving bell spiders need air to survive. How do they manage to breathe air underwater?


To know how these spiders achieve this feat, we must account for two special features.


First, they spin waterproof webs.


Second, they have water-repellent hairs on their abdomen.


The spider uses two techniques to arrange for air in water.


#1 The spider encloses its abdomen in a bubble of air, like a tiny personal oxygen tank. Much like scuba divers, they can carry this air bubble as they venture out to prey on aquatic critters and even tadpoles. The spider has to refill its air supply often. To do so, the spider surfaces and captures air on its hairy abdomen. Since the hairs repel water, the trapped air can form a bubble.


#2 The second method is a work of web art. Diving bell spiders weave a waterproof web that can trap air bubbles. The “diving bell,” as the web has been named, has a few more tricks up its sleeve. The web can “breathe” dissolved oxygen in from water, just like the gills of fish. To replenish its “airy household,” the spider infuses it with air bubbles that it carries on its abdomen.


These spiders live out the entirety of their lives underwater, despite having all the features akin to land spiders. A diving bell spider can practically do anything, from eating to laying eggs, in the air pocket of its web.


Flesch Kincaid Grade  Level: 6.1


Flesch Kincaid Reading Ease: 72.7

Copyright @smorescience. All rights reserved. Do not copy, cite, publish, or distribute this content without permission.

Join 20,000+ parents and educators
To get the FREE science digest in your inbox!