Sea Spiders are found primarily in the Mediterranean Sea and the Caribbean Sea.
There are about 1000 species of sea spider and they range in size from extremely tiny one celled creatures to a bit larger, perhaps a quarter inch.
Sea spiders have very long legs in comparison to their small bodies. They have four pairs of legs however species do exist which have five or six pairs as well.
Due to their small size and body they have no need of a breathing or respiratory system. They move oxygen and other gases by the use of diffusion.
They take nutrients into their bodies with the proboscis sucking it into their bodies from small invertebrates.
So small are these little guys that they are built with muscles that contain only one cell surrounded by other connective tissue.
The sea spider does have separate sexes except for one species which is both male and female. Females do have ovaries while the male possess his own sex organ near the digestive tract.
Scientists have surmised that their reproduction is an external one which takes place after a very short courtship, but a lot of the lives of pycnogonids are unknown.
The male of the species cares for the young and the eggs. The little ones consist primarily of a head and three pairs of legs.
Not much is known about the development of the larva. The adults are free living, while the larvae and the juveniles are living on or inside temporary hosts for them such as perhaps clams.
When the larva hatches it still looks like an embryo, and immediately attaches itself to the legs of the father, where it will stay until it has turned into a small and young juvenile with two or three pairs of walking legs ready for a free-living existence.”