March 22, 2005
From: Cynthia Trowbridge
I have been working with Yoshiaki and Yayoi Hirano and their students (Chiba University) for several years. We have just completed our 6th sacoglossan survey of Okinawa and I venture to comment on some of the 'Placida dendritica' (in the broadest sense) species found in Okinawa.
Locality: west coast of Okinawajima, Okinawa, Japan, East China Sea. Depth: 1 m . Length: several mm (data in Japan). 10-15 March 2005. rocky intertidal or shallow subtidal. Photographer: Tomohiro Watanabe.
I agree with Kathe's statement [#4177] that the French Polynesian 'Placida dendritica' really belong to Ercolania. This species (or a sibling one) is very common in Okinawa but I will present details about it separately.
Next, there are two species (?) of 'Placida' associated with Codium in Okinawa. The first is very, very, very common: we have collected hundreds on Codium intricatum and some on the coexisting C. arabicum. They were on Codium during every one of our 6 trips -- thus, this species appears to be present all year around. The radular teeth are blade-shaped but I have not looked at the reproductive system yet. I have started sequencing the COI gene of this animal. I think that this species may be what Kathe was calling Stiliger / Placida verticillata....? [Photos: A, B ]. I would be eager to hear others' views.
The second form or species (?) is much less common [Photo: C]. We have only collected 2 individuals of this from Codium (March 2005). This animal looks much more like what Baba (1986) called Placida sp. (=Hermaea dendritica). It has shorter rhinophores that flare a bit terminally. It looks much more like the Placida sp. (sensu Baba 1986) that we find in Sagami Bay.
Baba K (1986) Anatomical information on Placida sp. = Hermaea dendritica of Baba, 1937 and 1955, from Japan. Shells and Sea Life 18:21-22
Finally, we have yet another Placida species associated with Bryopsis from Okinawa and Izu Peninsula. I will present that species separately.
I would be keen to hear what you think about these sacoglossans.
Trowbridge, C.D., 2005 (Mar 22) Re: Okinawa Placida sp.?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13388
I think I will leave this for Kathe to comment on
Re: Okinawa Placida sp.
From: Kathe R. Jensen, June 21, 2002
Okinawa Placida sp.
From: Bob Bolland, June 20, 2002
Re: Placida dendritica (?) from French Polynesia
From: Kathe R. Jensen, February 16, 2002
Placida dendritica (?) from French Polynesia
From: Daniel L. Geiger, December 20, 2000
Placida dendritica? from Taiwan
From: Jui-Sheng Chang, March 11, 2000