Roboastra tigris
Farmer, 1978

Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: ANADORIDOIDEA
Family: Polyceridae
Subfamily: Nembrothinae

DISTRIBUTION

Gulf of California

PHOTO

UPPER: Adult about to eat a specimen of Tambja abdere. LOWER: Juvenile. Both animals were collected in Bahia de Los Angeles, Baja California, 2000. PHOTOS: Angel Valdes.

It can grow to 12 inches (30 cm) in length and feeds on other nudibranchs which it grasps with its radular teeth and swallows whole. It is reported to feed on the bryozoan-feeding nudibranchs Tambja eliora and Tambja abdere and is also cannibalistic, eating others of its own kind.

Reference:
•Farmer, W.M. 1978. Tambja and Roboastra (Mollusca, Opisthobranchia) from the Gulf of California and the Galapagos Islands. The Veliger, 20: 375-385.

Authorship details
Rudman, W.B., 2000 (December 28) Roboastra tigris Farmer, 1978. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/robotigr

Related messages


Re: Roboastra tigris? from Galapagos

January 25, 2004
From: Juan Lucas Cervera

Dear Patty and Bill,
The Roboastra from Galapagos is an undescribed species that is enclosed within a submitted manuscrit co-authored by Marta Pola, Terry Gosliner and I. In the manuscript, we review all the species of the genus, as well as their phylogenetic relationships.

Regards.
Lucas.

lucas.cervera@uca.es

Cervera, J.L., 2004 (Jan 25) Re: Roboastra tigris? from Galapagos. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/12013

Thanks Lucas,
I look forward to seeing the manuscript
Bill Rudman

What is a Sea Tiger ?

July 29, 2001
From: Charlie Richardson

A few years ago I saw a nature program showing a sea tiger, a large green and black animal with a bright blue mouth that ate everything that it came across. I can't find any information on the internet about these animals. Are they some kind of sea slug? If anyone has any ideas or pictures let me know,
Thanx,
Charlie

charlie.richardson@bt.com

Richardson, C., 2001 (Jul 29) What is a Sea Tiger ?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/4934

Dear Charlie,
The animal you are interested in is probably a sea slug called Roboastra tigris. It doesn't actually eat everything it comes across, but it certainly makes short work of the nudibranchs it likes to eat. Have a look at the Roboastra tigris Page and at the messages below yours on this page for more information.
Best wishes,
Bill Rudman

Rudman, W.B., 2001 (Jul 29). Comment on What is a Sea Tiger ? by Charlie Richardson. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/4934

Re: Photos of Roboastra tigris feeding

January 14, 2001
From: Angel Valdes

Dear Bill,

Regarding your question on the bluish tinge in the region where the Roboastra and the Tambja are meeting, I'm afraid it is just a reflection from the water. I think I had my flash to close to the water when I took the photo.

Which is very interesting to me is the way Roboastra orientates the rhinophores. When the animals are crawling around they have the rhinophores oriented towards the laterals of the body (like in the first picture), but when they are close to a prey they move them forward forming a "V". I suspect they use this system to locate the position of the preys more precisely. This seems to be similar to the triangulation system used in navigation. I saw this behavior in several specimens examined and it is very spectacular.

All the best,
Angel

avaldes@calacademy.org

Valdes, A., 2001 (Jan 14) Re: Photos of Roboastra tigris feeding. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3527

Thanks Angel,
Bill Rudman

Photos of Roboastra tigris feeding

January 13, 2001
From: Angel Valdes


Dear Bill,

In answer to your request, please find enclosed two pictures of Roboastra tigris for the Forum. The upper one is a juvenile specimen, and the lower one is a picture of an adult that is about to eat a specimen of Tambja abdere. Both animals were collected in Bahia de Los Angeles, Baja California, last year.

Happy new year to you and all the visitors of the Forum.

All the best,
Angel

avaldes@CalAcademy.org

Valdes, A., 2001 (Jan 13) Photos of Roboastra tigris feeding. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3519

Thanks Angel,
Is the bluish tinge in the region where the two animals are touching, secretions from the Tambja?
Best wishes,
Bill Rudman

Rudman, W.B., 2001 (Jan 13). Comment on Photos of Roboastra tigris feeding by Angel Valdes. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3519

The Ravenous Sea Tiger

December 31, 2000
From: Josh Barrax

I watched a program a few years back and saw footage about the sea tiger sea slug, but can find no information on the web about this striking representative. Any information on where I may learn more about the sea tiger would be greatly appreciated.
Josh Barrax

barrax63@yahoo.com

Barrax, J., 2000 (Dec 31) The Ravenous Sea Tiger. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3299

Dear Josh,
I think you are probably referring to Roboastra tigris which is found in the Gulf of California. It can grow to 12 inches (30 cm) in length and feeds on other nudibranchs which it grasps with its radular teeth and swallows whole. I am afraid I don't have a photo of this interesting animal but with luck, someone reading this will be kind enough to send some photos to the Forum and some further information. One reference is:

•Farmer, W.M. 1978. Tambja and Roboastra (Mollusca, Opisthobranchia) from the Gulf of California and the Galapagos Islands. The Veliger, 20: 375-385.

Best wishes,
Bill Rudman.