Warty Nurdibranch, Phylidiella pustulosa, Kai Islands, Moluccas, Indonesia

Dorid Nudibranch, Mexichromis multituberculata, Ambon, Moluccas, Indonesia

Neon Sea Slug, Thecacera picta, Triton Bay, West Papua, Indonesia

Sap-sucking sea slug (Elysia ornata), Malapascua, Cebu, Philippines, Southeast Asia, Asia

Nudibranch, Jorunna funebris, feeding on blue sponge, Haliclona sp., Monkey beach, Puerto Galera, Mindoro, Philippines.

Dorid nudibranch, Glossodoris averni, La Laguna, Puerto Galera, Mindoro, Philippines.

Polycerid nudibranch, Nembrotha cristata, external gill detail, Puerto Galera, Mindoro, Philippines..

Pyjama Chromodoris quadricolor (Chromodoris Quadricolor) Magnificent star snail, nudibranch, Red Sea, Aqaba, Kingdom of Jordan

Nudibranch Eye-spotted warty snail (Phyllidia ocellata) crawls through coral reef in search of food, Indian Ocean, Mascarene Islands, Mauritius, Africa

An Imperial commensal shrimp (Periclimenes imperator), photographed at night on the Spanish dancer nudibranch (Hexabranchus sanguineus), that it calls home, Philippines

Mediterranean Dorid Slug, Hypselodoris elegans, Tamariu, Costa Brava, Mediterranean Sea, Spain

Swimming Flatworm, Pseudoceros spec., Short Dropoff, Micronesia, Palau

Swimming Flatworm, Pseudoceros spec., Short Dropoff, Micronesia, Palau

Nudibranch (Dendronotus robusta) on brown algae commonly called kelp Tasiilaq, East Greenland

BLUE DRAGON (Glaucus atlanticus). A small peacic slug that measures only about 2 cm and is generally associated with the Portuguese frigatebird (Physalia physalis) or the blue button (Porpita porpita) on which it feeds. They can also appear in intertidal pools. Marine invertebrates of the Canary Islands, Tenerife.

Blue Dragon (Glaucus atlanticus) hanging. Small slug that measures only about 2 cm and is generally associated with the Portuguese man of war (Physalia physalis), although it also usually appears in intertidal pools. Marine invertebrates of the Canary Islands, Tenerife.

BLUE DRAGON (Glaucus atlanticus). Small slug that measures only about 2 cm and is generally associated with the Portuguese man of war (Physalia physalis), although it also usually appears in intertidal pools. Marine invertebrates of the Canary Islands, Tenerife.

Blue Dragon (Glaucus atlanticus). Small slug that measures only about 2 cm and is generally associated with the Portuguese man of war (Physalia physalis), although it also usually appears in intertidal pools. Marine invertebrates of the Canary Islands, Tenerife.

Nudibranch ( picta azorica). This subspecies is known only from the Azores. Santa Maria Island, Azores, Portugal, Atlantic Ocean

Four-colour nudibranch (Godiva quadricolor) on a plastic bottle in Laguna Torrefumo, Mediterranean sea, Italy

Giant Doris (Felimare picta), off Calella de Palafrugell, Costa Brava, Spain

(Dendronotus robusta) nudibranch on brown algae commonly called kelp in front of an iceberg, Tasiilaq, East Greenland

Four-colour nudibranch (Godiva quadricolor), Laguna Torrefumo, Gulf of Naples, Tyrrhenian Sea, Mediterranean Sea

Detail of a Krohn's Doris (Felimida krohnien) moving on rock, Ile d'Oleron, France