Marine Invertebrate of the Week: Sea Slugs

Sea slugs are very diverse marine invertebrates that lack shells. Instead of the protection of a shell, sea slugs have developed acids, toxins, stings, and camouflage. They are hermaphroditic, meaning individuals possess both male and female reproductive organs. Some sea slugs are herbivores, but most are specialized predators that feed on a single species. There are over 150 species of sea slugs in Hawai’i.

Spotted Swallowtail sea slug (Chelidonura sp.)

Spotted Swallowtail sea slug (Chelidonura sp.)

These Spotted Swallowtail sea slugs were spotted in the MLCD on Sunday. Although many sea slugs are brightly colored, some blend well into their environment. Most are also very small in size, ranging from 3/4 of an inch to up to 8 inches. The ones pictured here are about 1 inch long.

To learn more, check out these links:

• Sea Slugs of Hawaii
• Hawaiian Nudibranchs and Flatworms
• Hawaiian Sea Slugs