Hypselodoris maculosa (Pease, 1871) 23mm
OPISTHOBRANCH OF THE WEEK
Opisthobranch of the Week Data
Frequency on Okinawa:
- Order: NUDIBRANCHIA
- Suborder: Doridina
- Family: Chromodorididae
[brackets indicate range for all Okinawa-collected specimens of the species]
- Individual Collection No: RFB #3663-A
- Location: Horseshoe Cliffs, Okinawa (26o30.0'N, 127o50.9'E) [Horseshoe, Seragaki, Tengan]
- Date: 28 June, 1998 [24 collected since 14 Mar '87]
- Depth: 10ft (3m) [10ft (17 indiv), 20ft (2 indiv), 30ft, 40ft, 140ft, 175ft, 180ft]
- Water temperature at collection depth: Not recorded
- Size: TL 23mm [5mm ~ 25mm]
- Specimen deposited: RFB Personal Research Collection
Hypselodoris maculosa is considered to be common on Okinawa; twenty-four specimens have been collected since the first was collected on 14 March, 1987, although numerous others have been seen but not collected. The animal is typically found on Okinawa while crawling amid live stony coral reef environments, as was the featured animal above.
H. maculosa is similar in appearance to another Okinawan chromodorid, Thorunna australis. Bill Rudman (1998) points out that although T. australis has "some similarities to some colour forms of Hypselodoris maculosa but whereas that species has multiple longitudinal white lines Thorunna australis has only one on either side of the mantle. Both species have reddish bands on the rhinophores, always one in T. australis but up to three in H. maculosa." Here are images of two additional specimens of H. maculosa.
The species is widely distributed from the western Indian Ocean of Tanzania, the Red Sea, Christmas Island, the western Pacific coast of Australia and Enewetak (all Rudman, 1986), and Guam and Okinawa (Gosliner & Johnson, 1999).
- Gosliner, T. M. and Johnson, R. F. 1999. Phylogeny of Hypselodoris (Nudibranchia: Chromodorididae) with a review of the monophyletic clade of Indo-Pacific species, including descriptions of twelve new species. Zool. Journ. Linnean Soc. 125:1-114, with 62 figures.
- Rudman, W.B. 1986. The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Noumea purpurea and Chromodoris decora colour groups. Zoological Journal of the Linnean Society 86(4): 309-353.
- Rudman, W.B., 1998 (November 11) Thorunna australis (Risbec, 1928). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/thoraust
Page Date: 27 Sep '99
Page Modification Date: 27 Sep '99
Digitally manipulated photo
Copyright © 2000 Robert F. Bolland