Re: Ercolania coerulea from Hong Kong

March 22, 2005
From: Cynthia Trowbridge

Dear Bill and Kathe,

I have just returned from another Okinawa trip with the Hiranos and students (from Chiba University). We found 7 Ercolania species on this 5-day trip including the one shown here.

This species was found on Valonia sp. and Dictyosphaeria cavernosa at several sites on the west coast of the main island of Okinawa (Okinawajima). Specimens from Dictyosphaeria are rather bluish; animals from Valonia are not.

Locality: west coast, Okinawajima, Japan, East China Sea. Length: several mm (data in Japan). 10-15 March 2005 . shallow subtidal. Photographer: Tomohiro Watanabe

Would you call this species Ercolania coerulea? The reasons I think this may be the species include:

• Bright green from color of ingested chloroplasts
• Transparent except for reno-pericardium which is conspicuously white
• Prominent, elongate pericardium
• Digestive gland has a thin branch with short side-branches in each ceras (see close-up)
• Fine network of diverticula on dorsal surface of head
•  Long, simple rhinophores with diverticula almost to tip
• Anterior foot corners are drawn out

We will dissect the radular teeth in the next few weeks (which Kathe suggested should be large and sabot-shaped). I was hoping for a tentative identification as it may be a new record for Japan (e.g., not in Nakano 2004, Ono 2004, on the Okinawa Slug Site, or in any of Baba's papers). If colleagues from Japan have verified or unverified records of this species, I would grateful for details. Thanks!

All the best,

Cynthia

trowbric@onid.orst.edu

Trowbridge, C.D., 2005 (Mar 22) Re: Ercolania coerulea from Hong Kong. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13385

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