March 8, 2000
From: Bernard Picton
Here are two specimens which I think must be Halgerda willeyi - both from Taiwan (Formosa) in 1983. In view of the recent doubt re. the name formosa ..... I haven't seen the description of H. formosa or the recent paper but I hope Terry & Shireen have it right now! The smaller individual I have seen has far fewer dark makings than the larger one. I could look up my notes to get the sizes if that's important.
firstname.lastname@example.orgPicton, B., 2000 (Mar 8) Halgerda willeyi from Taiwan. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2013
Yes I think this is H. willeyi which has a wide Indo-West Pacific distribution.
The name 'formosa' doesn't actually refer to the Formosa (Taiwan), it was originally described from Reunion Id in the Indian Ocean. I am pretty sure 'formosa' means sweet or beautiful and I have this vague memory that it was this meaning that some early European explorer applied to Taiwan - because of some sweet smelling spices or perfume.
I have included the original colour figures of Halgerda formosa from Bergh, in my comments on your photo of Halgerda formosa.
Halgerda willeyi from Saudi Arabia
From: Gert Van Roey, July 22, 2008
Colour variations of Halgerda willeyi
From: Gary Cobb, September 8, 2007
Halgerda johnsonorum? at Pulau Aur, Malaysia
From: Yap Ting Wee, August 11, 2007
Halgerda willeyi from Iriomote Is., Japan
From: J.R. Pahlano Daud, April 5, 2007
Halgerda willeyi from the Kermadec Ids
From: Ian Skipworth, April 29, 2006
Halgerda willeyi ? from the Red Sea
From: Joseph De Vroe, December 2, 2005
Halgerda willeyi from Myanmar
From: Mary Jane Adams, March 26, 2003
Halgerda willeyi from Lord Howe Island
From: W.B. Rudman, January 29, 2003
Halgerda willeyi from Jervis Bay, eastern Australia
From: Allan Saben, November 22, 2002
Halgerda from the Philippines
From: Erwin Koehler, October 18, 2002
Re: Halgerda in temperate Australian waters?
From: Leander Wiseman, October 7, 2002
RE: Juvenile Halgerda sp. from Taiwan
From: Nishina Masayoshi, July 18, 2002
Halgerda iota? from Malaysia
From: Richard Houghton, July 12, 2002
Halgerda willeyi? mating with???
From: Erwin Koehler, May 2, 2002
Halgerda willeyi? from the Adriatic
From: Tom Turk, February 6, 2001
Halgerda willeyi? from Philippines
From: Fredy Brauchli, July 12, 2000
Halgerda willeyi from the Philippines
From: Bernard Picton, March 8, 2000
Halgerda willeyi from Mooloolaba?
From: Wayne Ellis, June 17, 1998