Spiders demonstrate astonishing intelligence. Certain orb web weavers actually build dummy spiders out of dead insects they've captured and glue the parts together with their silk (which reflect UV rays). When a wasp decides to go get a spider for lunch, their senses, which use UV rays, are fooled into believing the dummy to be real and attack it about 60% of the time giving the spider just enough time to escape. Many military defense mechanisms used on planes, vehicles and ships work on this same principle.
When I stated earlier than spiders could go back to the ocean if they chose, it was because some already have.
Desis martensi build little silk-lined air chambers in rubble left between tides. The tides come in then go out leaving behind stranded marine life that the spiders then come out to eat enjoying a smorgasbord of seafood. The one pictured here is enjoying a shrimp.
A giant sea spider from Antarctica with a 10" diameter leg span. These were only recently discovered. Their existence came as a complete surprise.
Arctic sea spider. Much smaller than their Antarctic counterparts.
The horseshoe crab is NOT a crab but an arthropod very closely related to arachnids. They are so ancient in design as to be considered living fossils. They range in size from a coin to a washtub.
Horseshoe crabs resemble trilobites a great deal. Trilobites were arthropods from about 500-250 million years ago. One of the first successful macroscopic life forms. In them one also sees centipedes. millipedes, sow bugs and other creatures. They ranged from small to very large in size and were very diverse. This fossil is from my own collection.
One can see how a trilobite-like creature could eventually evolve into the spider.
Australian funnel web spider--very toxic.
As dangerous as this spider's bite is, she is a lovely spider in her own little way.
Australian funnel web spider with mites around her beady, little eyes. These mites are not parasitical but simply use her to get around.