Micrathena gracilis

She’s got venom! She wears black, and she’s spiky like a demon! She’s a maiden of death, leaving behind her vicious fangs a string of hideous, staring corpses. Yeah! She delivers APOCALYPSE!

 . . . Well, if you’re a leafhopper, that is.

This little predator is often called the “spined micrathena,” but then again all three of our micrathenas are spiny, so you might as well learn its proper name: Micrathena gracilis (my-cruh-THEE-nah grah-SILL-us). By the way, I’m not being reverse-sexist by calling her a “her.” In almost all cases, when you see a spider living in a web, it’s a female. As a general rule, spider males are quite small, rarely spin webs, and have a single goal in life. And they don’t tend to live very long :/

Micrathenas are notorious for being one of the spiders that commonly builds webs across hiking trails. Micrathenas create beautiful and delicate orbs. There’s nothing clumsy about their webs. They’re shimmery and full of parallel lines so closely spaced that a mosquito cannot sneak through, and the spiders (which prefer to rest belly-up) move about their homes with grace, walking forward with their front three pairs of legs and using the back pair as a smooth-sliding hanger for the giant hind end. Usually, when seriously harassed, micrathenas plummet straight to the ground for safety.

Jumping Spiders

Jumping spiders live all around us. In fact, there are more than 4000 different species of jumpers.

The jumping spider can jump 20 to 60 or even 75-80 times the length of their body. If you were just five feet (1.5 m) tall and could jump like that, you could leap over the Buddha statue in Japan which is 328 ft (110 m) tall (one of the world’s tallest statues).

When a jumping spider is moving from place to place, and especially just before it jumps, it tethers a filament of silk to whatever it is standing on. Should it fall for one reason or another, it climbs back up the silk tether.

All  jumpers have eight eyes, and two of the eyes seem enormous for such a little body. Jumpers have a superb vision which is better than any other kind of spider. With his eight eyes a jumper can see in almost every direction at once. When it is darkest, you are looking into its retina and the spider is looking straight at you.

Jumping spiders are also very famous for their curiosity because jumpers in contrast to other  arachnids are seemingly interested in whatever approaches them. If approached by a human hand, instead of running away to safe place as most spiders do, jumpers will usually leap and turn to face the hand. Further approach may result in the spider jumping backwards while still eyeing the hand. The curious little creature will even raise its forelimbs and “hold its ground”.

Their big eyes are so sharp, they can see things clearly from as far away as 20 times the length of the spider’s body. No wonder, scientists who study jumping spiders say they’re some of nature’s best stalkers – as good as lions and tigers. They usually see their prey before their prey sees them!

Vampire sea spiders

Weird spider-like creatures that live at the bottom of the ocean and use a 'straw' to suck on their prey are baffling scientists.

These sea spiders, some of which are blind, are defying scientific classification. 

Marine zoologist Dr Claudia Arango of the Australian Museum in Sydney agrees they are arthropods, but which type? 

She presented her research on these unusual and poorly understood animals recently at the Scientific Committee on Antarctic Research meeting in Hobart.

"They are very weird looking animals," says Arango.

For over 100 years, scientists have been puzzling over how exactly to classify sea spiders or pycnogonids.

They crawl along the bottom of the sea floor, sometimes more than 6000 to 7000 metres down, where they live in the dark, feeding on slow-moving soft-bodied sponges and sea slugs.

The creatures are segmented and have an exoskeleton, which makes them an arthropod, the same grouping as crustaceans, insects, centipedes and spiders.

But they also have a very strange collection of features, including a unique feeding structure.

"They have a proboscis that's like a straw that they insert into the animals and suck out the juices," says Arango.

Such features make it difficult to fit them into any of the known groups of arthropods.

"They look like spiders, but they are not real spiders," says Arango. "It's been very hard to place them in a position within the tree of life."

Arango has been studying the diversity and evolution of sea spiders.

She has been using DNA and morphology to construct a family tree, using 60 species of sea spiders from all over the world.

This Antarctic sea spider has a 70-centimetre leg span
 (Image: Claudia Arango)

Some scientists believe that sea spiders make up a new very primitive group, at the base of the arthropod family tree.

But Arango's findings so far support another theory: that they are more closely related to the arthropod group that includes spiders and scorpions.

She stresses these are only preliminary conclusions though, and the jury remains out.

Arango says the most interesting sea spiders live in Antarctica. They are more diverse, more abundant, bigger and weirder than other sea spiders, she says.

"That makes them a very sexy and attractive fauna."

One type of Antarctic sea spider has an extra body segment giving them five pairs of legs instead of the usual four pairs.

Another type has extremely long legs spanning 70 centimetres. 

Arnago says the diversity and abundance of sea spiders in Antarctica means they probably play a very important role in its ecology, although this is yet to be elucidated.