Project Noah

Project Noah is a tool to explore and document wildlife and a platform to harness the power of citizen scientists everywhere.

Join Project Noah Today

Purplelined Nudibranch

Ceratosoma tenue


Also known as Tenue Sea Slug, T-bar Nudibranch, Purple-edged Ceratosoma, Long-tail Ceratosoma. They feed on hydroids, coral, sponges and sea anemones, and grow to a length of about 11cm. This species can easily be mistaken for either of two species in its genus: C. gracillimum and C. trilobatum. The telling difference is the presence of extra lateral lobes in C. tenue. You can see those lobes just behind its head. (See picture #5)


Found singly or in pairs on coral and rocky reefs, in sand and rubble areas, at depths of 2 to 30m. Widespread in the Indo-Pacific region.


Spotted this elongated nudibranch at the Dayang Beach dive site in a little more than 9m of water. It measured approximately 6cm long.

No species ID suggestions


Blogie 5 years ago

Thanks, Maria! Me too, that's actually my favorite too. :)

Maria dB
Maria dB 5 years ago

especially like the fourth photo!

Davao Del Norte, Philippines

Lat: 6.95, Long: 125.67

Spotted on May 5, 2012
Submitted on May 5, 2012

Related spottings

Sinuate Ceratosoma Ceratosoma gracillimum Slender Ceratosoma Nudibranch with hitchhiking Emperor Shrimp Trilobatum Nudibranch

Nearby spottings

Ornate Ghostpipefish Giant Tun Mushroom Coral Ghost Shrimp Rainbow Mantis Shrimp