February 3, 2009
From: Sully & Monika Bachel
Concerning message #2345:
Here is a nudibranch found by my wife Monika. It was moving on a sandy rock and it is probably Hypselodoris nigrolineata
What is your opinion?
Locality: La Possession, 4 m, Reunion Island, Indian Ocean, 31 January 2009. Length: 35 mm. Photographer: Sully Bachel.
firstname.lastname@example.orgBachel, S., 2009 (Feb 3) Hypselodoris nigrolineata from Reunion Is.. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22219
This is an interesting find. There are very records of H. nigrolineata since its original description in 1904. I have only ever seen a couple of live specimens so your photos area valuable addition to our knowledge. There are a number of examples of what we can call 'species pairs' found in the Indo-West Pacific with two apparently closely related species with small external differences, one species found in the western Indian Ocean and the other in the western Pacific Ocean. Hypselodoris nigrolineata has such a pair in the western Pacific which we know as H. maritima. The main differences in colour pattern are that H. nigrolineata has black tranverse smudges around the mantle edge, which are absent in H. maritima, and H. maritima usually has a submarginal yellow band on the mantle which is absent in H. maritima.