Although sea spiders are not true spiders, or even arachnids, their traditional classification as chelicerates would place them closer to true spiders than to other well-known arthropod groups, such as insects or crustaceans.
If you have an HDTV, we strongly recommend that you buy a Blu-ray player rather than a standard DVD player. Prices for Blu-ray players now start at less than $100, but expect to pay a bit more for a major-brand player that has 3D and wireless capbility.
The DVD you have has the latest encoding, so your antique DVD player has finally met a disc it won't play. Now days, most people update the firmware on their DVD players to stay compatible with the latest DVD encoding processes. All you need is a new DVD player. My preference is a $99 Sony.