Roboastra luteolineata (Baba, 1936) 105mm
OPISTHOBRANCH OF THE WEEK
Opisthobranch of the Week Data
Frequency on Okinawa:
- Order: NUDIBRANCHIA
- Suborder: Doridina
- Family: Polyceridae
[brackets indicate range for all Okinawa-collected specimens of the species]
- Individual Collection No: RFB #2141
- Location: Seragaki, Okinawa (26° 30.4'N, 127° 52.6'E) [Horseshoe, Seragaki]
- Date: 3 May, 1989 [14 Apr '89, 3 May '89, 11 May '89, 23 Dec '91, 16 Mar '97]
- Depth: 40ft (12m) [10ft, 20ft, 40ft, 160ft, 185ft]
- Water temperature at 20ft: 74.5°F (23.6°C)
- Size: TL 105mm [53mm, ca.75mm, 95mm, 105mm, 115mm]
- Specimen deposited: RFB Personal Research Collection (different individuals of the species deposited at Cal Acad Sci)
Roboastra luteolineata is considered to be rare on Okinawa; five specimens have been collected including the first, which was collected on 14 April, 1989. The above featured animal was found during a mid-morning SCUBA excursion crawling upon the surface of open sand within a meter of a dead stony coral reef.
Roboastra luteolineata was first described by Baba (1936), as Nembrotha luteolineata, from Ishigaki Island, Japan. There seems to be quite a bit of confusion in the popular literature between this animal and Tambja affinis. Bill Rudman (1999) points out the most distinctive external feature of this species is the milky green markings between the rhinophores, which distinguish it from other black nembrothids with yellow longitudinal lines down the body.
The only other Roboastra species I've found here to date (September, 1999) is Roboastra gracilis.
- Baba, K. 1936. Opisthobranchia of the Ryukyu (Okinawa) Islands. Journal of the Department of Agriculture, Kyushu Imperial University 5(1):1-50, pl. 1-3.
- Rudman, W.B., 1999 (February 22). Roboastra luteolineata (Baba, 1936). [In] Sea Slug Forum. http://www.austmus.gov.au/seaslugs/robolute.htm.
Page Date: 13 Sep '99
Page Modification Date: 22 Oct '01
Digitally manipulated photo
Copyright © 2001 Robert F. Bolland