Siphopteron sp. 1 (ca. 3mm)
OPISTHOBRANCH OF THE WEEK
Opisthobranch of the Week Data
Frequency on Okinawa:
- Order: CEPHALASPIDEA
- Family: Gastropteridae
[brackets indicate range for all Okinawa-collected specimens of the species]
- Individual Collection No: RFB #3585-D
- Location: Seragaki, Okinawa (26o 30.4'N, 127o 52.6'E)
- Date: 4 May, 1997 [only a single collected specimen]
- Depth: 180ft (55m)
- Water temperature at collection depth: 70oF (21oC)
- Size: TL ca. 3mm [only a single collected specimen]
- Specimen deposited: California Academy of Sciences
- Photo Data: Original Kodachrome shot at 4:1
Siphopteron sp. 1 is considered to be very rare in the waters of Okinawa's main island as I have seen and collected only the single above featured animal. It was found as a collaterally-collected specimen shortly following a SCUBA excursion. Later at home while observing material in a sorting bowl, originally composed of a zip-loc bag of misc. cnidaria, algae, coral rubble and sand, this tiny gastropterid was found swimming about by actively flapping its parapodia. This behavior was noted again moments later in a small glass photo tank.
Rudman (1999) commenting in the Sea Slug Forum feels that this animal should perhaps be considered a species of Gastropteron as there is no indication of the siphonal crest characteristic of the genus Siphopteron. Ono (2004) illustrates several similar 3mm & 4mm animals in his recent book* (as Gastropteron spp. 1 & 2, pp. 24-25). Until the taxonomy is confirmed I'll leave the animal as an unknown species of Siphopteron.
* This beautifully illustrated book is available from:
- Gosliner (1989) chose the generic name Siphopteron in reference to the prominent siphonal crest and parapodial "wings" which characterize members of the genus.
- Gosliner. T.M. 1989. Revision of the Gastropteridae (Opisthobranchia: Cephalaspidea) with descriptions of a new genus and six new species. The Veliger, 32(4): 333-381.
- Ono, Atsushi. 2004. Opisthobranchs of Ryukyu Islands, Rutles, Inc., Tokyo, Japan. 304pp.
- Rudman, W.B., 1999 (July 27). Comment on Siphopteron sp. 1? from Okinawa by Bob Bolland. [Message In] Sea Slug Forum. http://www.austmus.gov.au/seaslugs/list.htm.
Page Date: 26 July '04
Page Modification Date: 26 Jul '04
Digitally manipulated photo
Copyright © 2004 Robert F. Bolland