Unlike the majority of spiders, which dwell on land, the diving bell spider spends most of its life underwater ... enlarges ...
Sea spiders look like arachnids living underwater, but they are not the same. They are marine arthropods in the class Pycnogonida and are called pycnogonids. However, they are related to spiders ...
Spiders come in all shapes and sizes ... even giant sharks, to live underwater in this video slideshow.