March 20, 1999
From: Lindsay Warren
Here is another mystery from Tukang Besi Islands, [Sulawesi, Indonesia - Operation Wallacea ]
Length: 3 mm. Simple rhinophores, white with transparent tip and base. Black collar around 'neck' behind rhinophores. White oral veil. Distinct eye spots. Cerata had black base with "most incredible dazzling colours on cerata - primarily pinks and greens like tinsel. Cerata nearer the foot were shorter and generally primarily black with green tip.
Underside shows translucent edge to foot with just green and pink sparkle."
Notum never visible due to clustered cerata. Tail white and very thin. Found at a depth of 5 m in between Sarcophyton soft coral on rubble covered in algal growths. This was referred to as the 'Christmas Tree Nudibranch'!
Photo: Adam Powell.
All the best
email@example.comWarren, L., 1999 (Mar 20) Costasiella sp from Sulawesi. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/692
My first thought was that it looks like a species of Cuthona, but the apparent lack of oral tentacles on the oral veil suggests it is not. Thanks for the field notes and sketches which confirm their absence. I think it is a sacoglossan and the eyes set closely together are characteristic of the genus Costasiella. Ichikawa (1993) described quite a few species of Costasiella from the Ryukyu Islands and one of these, Costasiella iridophora is similarly speckled with iridescent specks. However your animal has a very characteristic black "collar" behind the eyes which I have not seen described for a species of this genus so it is probably a new species.
Rudman, W.B., 1999 (Mar 20). Comment on Costasiella sp from Sulawesi by Lindsay Warren.
[Message in] Sea Slug Forum. Australian Museum, Sydney.
Available from http://www.seaslugforum.net/find/692
Ichikawa, M. (1993) Saccoglossa (Opisthobranchia) from the Ryukyu Islands. Publications of the Seto Marine Biological Laboratory, 36: 119-139.
Costasiella sp. 1.? from Okinawa.
From: Yasuhiro Shamoto, August 14, 2007
Re: Costasiella from Hawaii
From: Clay Carlson, November 17, 2003
Costasiella from Hawaii
From: Dan Barshis, November 16, 2003
Costasiella from Okinawa
From: Atsushi Ono, April 28, 2002
Re: Costasiella sp. 1 from Hawaii
From: Kathe R. Jensen, February 7, 2002
Costasiella sp. 1 from Hawaii
From: Cory Pittman, February 6, 2002
Costasiella sp. 1. from South Africa
From: Valda Fraser, February 5, 2002
Costasiella sp. 1 from South Africa
From: Lindsay Warren, February 5, 2002
Costasiella sp. 1 from Sulawesi
From: Lindsay Warren, July 28, 2000
Re: Colour in Costasiella
From: Clay Carlson & Patty Jo Hoff, March 25, 1999
Chemical defence in Costasiella
From: Bill Rudman, March 24, 1999
Costasiella sp. 1. from Guam
From: C Carlson & P.J. Hoff, March 23, 1999