When is a Spider not a Spider? | @mblwoodshole Published on September 13, 2016 FacebookPinterestTwitterLinkedin Anoplodactylus sp., sea spiders (class Pycnogonida) caught in Vineyard Sound. Pycnogonids are marine arthropods, not actual spiders, and are found from the Caribbean to the Polar seas. A video posted by Marine Biological Laboratory (@mblwoodshole) on Sep 9, 2016 at 5:45pm PDT Post navigation ← Scientists Work to Solve Westport River’s Eroding Salt Marsh Mystery | Buzzards Bay Coalition Q & A with Roger Hanlon | Current Biology Magazine →