On the holotype of Phyllidiopsis sinaiensis

September 9, 2003
From: Michael Schroedl

Hi Bill,
This is a contribution to the discussion on Phyllidiopsis sinaiensis.

I was quite surprised to see Bernard’s photograph of the “holotype” of P. sinaiensis. Redescribing that species, Alexander Fahrner and I re-examined a specimen from the British Museum of Natural History that was labelled as being the holotype of P. sinaiensis (BMNH 1986.231; see photograph) that clearly differs from that shown on Bernard’s photograph. The museum specimen refers to the original description of a single specimen by Yonow (1988) and to its redescription by Brunckhorst (1993). Thus, the specimen from the BMNH is the holotype of P. sinaiensis and Bernard’s photograph must have been somehow confused. Bernard’s specimen resembles Phyllidiella pustulosa due to tubercle pattern and black rhinophores. The principal distinguishing features of P. sinaiensis are as described by Fahrner & Schrödl (2000), including the central tubercle ridge, more or less large and multicompound, broad based, pink tubercles, bicoloured rhinophores with a black tip and the stalk black posteriorly and pink anteriorly, well developped rhinotubercles, the very elongate muscular oesophageal segment, the distinct stomach and the extremely long, convoluted prostate that is bound together by connective tissue. In some specimens, the bases of the tubercles may fuse leading to a predominantely pink dorsum with only a few black lines. The preserved holotype was described to show low and not compound dorsal tubercles by Yonow (1988) and Brunckhorst (1993) but this can be easily explained by the artificial abrasion of all central notum tubercles of the holotype (see Fahrner & Schrödl, 2000).

All specimens currently posted under P. sinaiensis but Bernard’s “holotype” appear to be true P. sinaiensis. In addition, the specimen from Jordan, Aqaba, of Erwin Koehler currently identified as Phyllidiopsis krempfi is certainly P. sinaiensis. Other P. krempfi apparently do not show a distinct tubercle ridge as characteristic for P. sinaiensis. Anyway, some P. krempfi at least externally may look quite similar to P. sinaiensis, and it may be tested by anatomical or molecular means whether or not P. sinaiensis is a Red Sea relative of the Indo-Pacific P. krempfi in the future.

• BRUNCKHORST, D.J. 1993. The Systematics and Phylogeny of Phyllidiid Nudibranchs (Doridoidea). Records of the Australian Museum, Supplement 16: 1-107.
• FAHRNER, A. & SCHRÖDL, M. 2000. Redescription of Phyllidiopsis sinaiensis (Yonow, 1988) (Nudibranchia: Doridoidea: Phyllidiidae), with a review of the Red Sea Phyllidiidae. Journal of Molluscan Studies, 66: 467-476.
• YONOW, N. 1988. Red Sea Opisthobranchia 1: The family Phyllidiidae (Mollusca: Nudibranchia). Fauna of Saudi Arabia, 9: 138-151.

Cheers,
Michael

schroedl@zi.biologie.uni-muenchen.de

Schroedl , M., 2003 (Sep 9) On the holotype of Phyllidiopsis sinaiensis. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/10101

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