Critter of the deep - Episode 3: Sea spider

Sea spiders are exclusively marine arthropods. They look a little bit similar to land spiders the arachnids, but they are in their own special group the Pycnogonida.

They can be very small, but the large specimen I have in my hands is from the Ross Sea in Antarctica, where sea spiders are found in large numbers and with high species diversity.

Male sea spiders carry eggs under their body with one of their appendages called an oviger, and when they hatch the babies are carried around by their dad while they are still developing.

Sea spiders use their long straw like proboscis to eat their prey - animals like soft corals, anemones and sponges. They have a very skinny body so their guts and reproductive organs extend down into their long skinny legs. They also do not have gills or lungs, so they absorb oxygen through their cuticle, (hard shell-like skin).

Here’s an article about genetic research done on Antarctic sea spiders:
niwa.co.nz/sites/niwa.co.nz/files/import/attachments/spiders.pdf

Here’s an interesting article about how Sea spiders eat:
frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-018-0250-4

NIWA contacts D7: 
Research subject: Biodiversity