- Sea Snakes: Venom, Characteristics, Behavior
- Sea Snake Species
- Echinoderms (Sea Stars, Sea Cucumbers and Sea Urchins): Characteristics, Behavior, Reproduction
- Sea Cucumbers: Characteristics, Behavior and Products
- Sea Cucumber Species: Big, Colorful, Toxic, Ugly and Edible Ones
- Sea Slugs: Strange, Violent Sex, Heads That Regrow Bodies and Sea Hare Orgies
- Solar-Powered Sea Slugs — Animals that Photosynthesize
- Nudibranchs: Characteristics, Mating, Colors
- Species and Types of Nudibranchs: Beautiful, Strange and Toxic Ones
- Plant-Like Marine Animals: Crinoids (Sea Feathers), Sea Pens and Gorgorians (Sea Fans, Sea Whips)
- Difficult-to-Classify Marine Animals: Sea Squirts, Phoronids, Bryzoans and Brachiopods
- Marine Worms: Polychaetes, Annelids and Flat, Fire and Ribbon Worms
- Weird Marine Worms: Penis Fencers, Purple Socks and Toxic Ones 55 Meters Long
- Sea Stars (Starfish): Characteristics, Feeding and Body Regeneration
- Sea Star (Starfish) Species
- Sunflower Sea Star: the Largest, Heaviest, Fastest and Most-Armed Starfish
- Crown-of-Thorns Starfish: Characteristics, Feeding, Coral Reef Damage
- Brittle Stars: Characteristics, Behavior and Unique Locomotion
