Herviella yatsui
(Baba, 1930)
Order: NUDIBRANCHIA
Suborder: AEOLIDINA
Family: Glaucidae
DISTRIBUTION
Quite common intertidally under stones on both the Pacific and Japan Sea coasts of Japan.
PHOTO
Shimoda, Izu Peninsula, Sagami Bay, Japan. In tide pool (Depth: 0.3m). 30 Sep 2001. Size: about 8-10mm. Photo: Jun Imamoto.
The skin of Herviella yatsui is translucent clear, with the colours of the viscera showing though. The main colour features of the animal include the head being marked by a black U with the arms extending into the basal half of the oral tentacles. There can also be a short black line on either side of the head beneath the rhinophores. The rhinophores have a black band about halfway along their length and the region above this band is partially or totally pigmeneted white. The dorsal part of the body is covered in irregularly shaped black spots but these are absent from the sides. There are also scattered white spots over the head, dorsum and sides of body. There is a white line or series of spots down the dorsal midline of the posterior foot ('tail').
The cerata have scattered black spots on the dorsal side, usually arranged in two clusters. The upper cluster is usually very dense and forms a black ring near the ceratal tip. The ceratal tip is colourless with a subapical band of white. There can also be a second band of white, or patch of white spots, midway along the cerata. It grows to approximately 15mm in length.
References:
• Baba, K. (1930) Studies on Japanese nudibranchs 3. A. Phyllidiidae. B. Aeolididae. Venus, The Japanese Journal of Malacology, 2(3): 117-125. (Pl.4)
• Baba, K. (1966) The anatomy of Herviella yatsui (Baba, 1930) and H. affinis Baba, 1960 (Nudibranchia - Eolidoidea). Publications of the Seto Marine Biological Laboratory, 14: 1-6,Pls.1-2.
Rudman, W.B., 2001 (October 2) Herviella yatsui (Baba, 1930). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/hervyats
Related messages
Herviella sp. ? from India
November 5, 2009
From: Vishal Bhave
Concerning message #4563:
I got this aeolid in rock pool at low tide beneath the rock encrusted with tiny hydroids and bryozoans, Richard Willan has suggested it could be a species of Herviella.
.Locality: Undi - Ratnagiri, 15 centimeters, Maharashtra, India, Arabian sea, 31 October 2009, Intertidal, beneath the rock, in rockpool. Length: 8 mm. Photographer: Vishal Bhave.
Vishal Bhave
vishalbhave@gmail.com
Bhave, V.J., 2009 (Nov 5) Herviella sp. ? from India. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22748
Dear Vishal,
I would agree that this is most probably a species of Herviella. The arrangement of the black pigmentation and absence of orange rings on the cerata, suggest that this is Herviella yatsui which is at present known only from Japan. As I have said in response to a number of your messages, we know little about most of these animals, so photos and records like this are valuable additons to our knowledge.
Best wishes,
Bill Rudman
Herviella yatsui from Japan
October 25, 2002
From: Jun Imamoto
Dear Bill,
I found this sea slug in a tide pool. I also found the same species there last year, too. This sea slug seems to be common in this place. I saw 4 individuals, 2 of which I photographed. I am happy if these reports are useful for your research.
Date: 21 Sep 2002
Location: Shimoda, Izu Peninsula, Sagami Bay, Japan
Size Approx: 8mm
Depth: 0.3m (Intertidal)
Temperature: 25C
Best Regards,
Jun Imamoto
http://umiushi.zive.net/
imamoto@wips.co.jp
Dear Jun,
Thanks for these further photos of Herviella yatsui. It is certainly a valuable addition to our understanding of this species
Best wishes,
Bill Rudman
Herviella yatsui from Japan
October 4, 2001
From: Jun Imamoto
Dear Bill
Though we went for scuba diving, the sea was so rough we couldn't dive. Instead we looked for any sea slugs on the nearby beach. We found a pool of about 30cm depth with many sea slugs. There was one sea slug which I couldn't name. I think that it is of the Facelinidae family.
Place: Izu Peninsula, Shimoda, Sagami Bay, Japan (Suzaki is near.) Depth: 0.3m. 30 Sep 2001. Size: about 8-10mm., Water temperature: 26C degrees.
Best Regards,
Jun Imamoto
imamoto@wips.co.jp
Dear Jun,
I am sorry you couldn't go diving but pleased that you found this interesting pool. This sea slug is one of many which seem to be found only in the intertidal region and so are often never seen by diving. Your species is Herviella yatsui which Baba reports is quite common intertidally under stones on both the Pacific and Japan Sea coasts of Japan. I have prepared a new page for the Forum on this species.
Best wishes,
Bill Rudman
