Underwater Spiders

Diving bell spider

Photo of a diving bell spider by Dr Stefan Hetz.

Professor Roger Seymour (School of Earth & Environmental Sciences, University of Adelaide) and Dr Stefan Hetz (Institute for Biology, Humboldt University) have provided new insights into the lives of diving bell spiders (Argyroneta aquatica), which are air-breathing spiders that spend the majority of their lives underwater.  The researchers’ study revealed that the spiders trap air in dome-shaped webs they build between aquatic plants.  These bubbles act as gills, extracting oxygen from the water and providing enough air for the spiders to breathe for more than 24 hours.  The spiders come up to the surface about once a day to supplement their air supply.

Up until now, scientists did not know how long the spiders stayed under water or how they used the diving bells to breathe.

According to Seymour:

Previous research had suggested the spiders had to come to the surface as often as every 20–40 minutes throughout the day.  Instead, we found that the spiders could sit still for long periods of time, continuing to use their diving bells to extract oxygen even from the most stagnant water on a hot day. Being able to stay still for so long – without having to go to the surface to renew the air bubble – protects the spiders from predators and also keeps them hidden from potential prey that come near.

Each spider constructs a net of silk in vegetation beneath the surface and fills it with air carried down on its abdomen and rear legs.  The spiders spend their entire lives submerged and even lay their eggs in their diving bells.  They are fascinating creatures but unfortunately they are becoming increasingly rare in Europe.

Seymour and Hetz’s findings will be published in The Journal of Experimental Biology.

Diving bell spider

Photo of a diving bell spider by Dr Stefan Hetz.

2010 Interesting Animal Discoveries

As 2010 comes to a close, we thought it would be fun to take a look back at some of the amazing animal discoveries that came to light in the past year.

Israel’s “Lifting Door” Spider
With a leg span of 14 cm (5.5 in.), a new spider found in the dune of the Sands of Samar in Israel is the largest of its type in the Middle East. In addition, scientists have concluded that Cerbalus aravensis is a nocturnal spider that lives in an underground den with a “lifting door” made of glued sand particles so the den remains camouflaged.

Cerbalus aravensis spider

Photo by Yael Olek


Ecuador’s Scaly-Eyed Gecko

Recent exploration by U.S. and Ecuadorian researchers have found more than 30 new species of animals in Ecuador, including the scaly-eyed gecko. A full-grown scaly-eyed gecko is small enough to sit atop the eraser of a pencil. These geckos crawl along the forest floor, making them difficult to spot.
Scaly-eyed gecko


Dinosaurs’ True Colors

Two groups of researchers using electron microscope technology have determined the true colors of two species of dinosaurs.  Sinosauropteryx, a turkey-sized carnivorous dinosaur, had reddish-orange feathers and striped tail.  Anchiornis huxleyi, a chicken-sized dinosaur, had black and white wings and red crown – similar to some woodpeckers.

Sinosauropteryx, a feathered dinosaur

Sinosauropteryx, a feathered dinosaur


All-Black King Penguin

An extremely rare all-black penguin was photographed near Antartica by Andrew Evans of National Geographic.  The king penguin doesn’t look like his tuxedoed counterparts because of what one scientist described as a “one in a zillion kind of mutation.”
All-black king penguin


World’s Largest (and Toughest) Spider Web

A newly discovered spider in Madagascar builds the longest and largest orb webs in the world. The spider, called Darwin’s bark spider, builds webs over rivers that can measure up to 2.8 square meters (about 30 square feet)!  The webs are made of the toughest biomaterial yet discovered and can catch 30 or more insects at any given time.
largest spider web


Reclusive Loris Photographed

One of the most reclusive primates in the world, the Horton Plains slender loris, has only been spotted four times since 1937. So rare were sightings that researchers thought this loris had gone extinct sometime between sightings in 1939 and 2002.  As deforestation has led to a decline in all populations of slender loris, researchers made the effort this year to study the nocturnal primates in their native habitat in Sri Lanka and southern India.  This photo was taken as part of the study.
Horton Plains slender loris


Giant Penguin Fossils

Scientists in Peru uncovered the fossils of a Water King, a giant 5-foot penguin that weighed twice as much as an emperor penguin (the world’s largest living penguin) and lived 36 million years ago.  The fossils, which included well-preserved feathers and scales, led scientists to determine that the Water King had brown and gray feathers, unlike the black and white feathers we associate with modern penguins, and it was a very strong swimmer and diver.
Giant Prehistoric Penguin

New Species of Spider Discovered in Israel

Cerbalus aravensis spider

Photo by Yael Olek

With a leg span of 14 cm (5.5 in.), a new spider found in the dune of the Sands of Samar in Israel is the largest of its type in the Middle East.  It was discovered in the southern Arava region in Israel and given the scientific name, Cerbalus aravensis.

Although scientists still need to conduct a full study of the creature, they do know that it is a nocturnal spider that lives in an underground den with a “lifting door” made of glued sand particles so the den remains camouflaged.

The Israel Land Administration plans to continue mining the Sands of Samar, which will reduce this spider’s habitat and jeopardize its survival.

For more information, see NatGeo News Watch.

Vegetarian Spider

vegetarianspiderNational Geographic reports that the Bagheera kiplingi, a jumping spider, has been recently identified as the only vegetarian spider in the world. Of the 40,000 species of spider in the world, this is the only species that eats primarily non-meat. Although the Bagheera kiplingi will occassionally eat ant larvae, they mainly eat acacia plant buds.

Read the whole article at National Geographic.