Marionia rubra

Order : NUDIBRANCHIA
Suborder : DEXIARCHIA
Infraorder : CLADOBRANCHIA
Parvorder : DENDRONOTIDA
Superfamily : TRITONIOIDEA
Family : Tritoniidae

DISTRIBUTION
Known from the Red Sea but here a record from the Lembeh Strait – Indonesia

Marionia rubra is characterized by its reddish-brown body colour, and by numerous bushy gills down each side of the body.
Let me quote the description in IPN at page 337: “Color variable from deep red to light green or brown. Notum covered with large, crowded tubercles that often are covered with opaque white pigment. There are 8-12 short velar appendages that have multifid tips. Margins of the rhinophoral sheaths are broad and undulating.”
Gosliner, Terrence M., David W. Behrens & Ángel Valdés. 2008. Indo-Pacific Nudibranchs and Sea Slugs. Sea Challengers Natural History Books.
Gig Harbor, Washington. 426 pp.
Note by Bill Rudman :”This group of tritoniids needs more work. At the moment it is hard to say how many species there are in the tropical Indo-West Pacific. It is possible that species vary in colour depending on the colour of the soft-corals they are feeding on but basically we don’t know.”  At this stage we do not know if the many available names for these soft-coral feeding tritoniids represent good species or colour variations.