Mediterranean, [Records from Caribbean and Japan need confirmation].
Antalya, Turkey, May 2002., Depth: 15m, Size: approx 4cm. Photo: Baki Yokes.
Notarchus is a genus of Sea Hare in which the parapodia are almost completely fused. There is a small anterior opening to allow an exchange of water to the mantle cavity. They have no shell. They are able to escape from danger by swimming by jet propulsion. A most spectacular if inelegant display which I have described in a message below.
There are two described species, Notarchus punctatus with an armed penis and Notarchus indicus without. N. punctatus is recorded from the Mediterranean. Baba, (1938) describes a subspecies N. indicus armatus from Japan, and subsequently Marcus (1962) removes it to the species N. punctatus, and identifies Caribbean animals as N. punctatus armatus. Notarchus indicus is known from much of the Indo-West Pacific under various names. Clearly the Caribbean and Japanese records need to be clarified and the subspecies armatus re-evaluated.
• Philippi, R.A. (1836) Enumeratio molluscorum siciliae. Berlin.
Rudman, W.B., 2002 (June 11) Notarchus punctatus Philippi, 1836. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/notapunc
June 13, 2002
From: Baki Yokes
The southern coast of Turkey has dense populations of Notarchus punctatus. They are found in sea grass meadows. The 6 specimens in the lower right photo, show how well established the species is, around Antalya, Turkey.
Photos: Baki Yokes
Place: Antalya, Turkey
Dive site: Uc Adalar
Date: May 2002
Size: all about 4cm
Yokes, B., 2002 (Jun 13) Notarchus punctatus from Turkey. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7199
Thanks for the photo of it swimming - I like the way it tumbles through the water like an out of control party balloon.