Janolus praeclarus
(Bouchet, 1975)
Order: NUDIBRANCHIA
Suborder: ARMININA
Family: Zephyrinidae
DISTRIBUTION
Known only from Senegal
PHOTO
Dakar, Senegal. April 1999, On Tacoma wreck at 10m. Photo: Patrice Petit de Voize
The body is translucent orange with parts of the viscera showing through the body wall. The brown digestive gland duct is clearly visible in each ceras. The white-tipped rhinophores are orange, as is the inter-rhinophoral crest. A thin, opaque white line, runs around the anterior half of the mantle just inside the cerata, curving in about halfway down the body to form an incomplete circle. A similar line runs around the posterior half of the mantle but it joins in the midline to run forward as a single line within the anterior circle. The white lines are not always present in their entirety. The cerata have an orange subapical band, and directly below that a creamy white or yellow band, which on the dorsal side of each ceras forms a white streak, which runs some distnace down the ceras. There is a cream yellow broken liine along the dorsal midline of the posterior foot.
Grows to at least 25mm in length. Bouchet (1975) reports finding it on the bryozoan Bugula fulva at 22 metres depth. It is at present known only from Senegal.
Reference:
• Bouchet, P. (1975) Nudibranches nouveaux des cotes du Senegal. Vie et Milieu, 25(1): 119-132.
Rudman, W.B., 2003 (May 1) Janolus praeclarus (Bouchet, 1975). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/janoprae
Related messages
Janolus praeclarus and its egg-ribbons
July 10, 2003
From: Marina Poddubetskaia
Dear Bill,
Here is Janolus praeclarus from Dakar. This species is quite common in Senegal. But 'Fayis' is THE site of Janolus. In this place I saw a multitude of J. praeclarus, I have never seen so many specimens of one species in the same place before. It was incredible! The largest specimen I saw was about 40mm in length.
Also, there were a lot of egg-ribbons and I had some difficulties to take good photos because of great surge. I saw one animal start laying but there were too much movement in the water and it abandoned the attempt quickly.
Date: June 07, 2003
Location: Dakar, Senegal, Eastern Atlantic
Site: Fayis
Depth: 17-19m
Size:
Animal: 25-30mm
Egg ribbon: 10-15mm in diameter
Photos: Marina Poddubetskaia - Nembro website
Best wishes,
Marina.
nembro@nembro.info
Thanks Marina,
For an animal which has only been reported a couple of times, you have given us some valuable information on its natural history. I have included [lower right], from one of your photos, a full size copy of the plant-like growth which is obviously abundant around the animals. This is an arborescent [=bushy] bryozoan - most probably the food of Janolus praeclarus.
Best wishes,
Bill Rudman
Re: Janolus from Senegal
May 3, 2003
From: Richard Willan
Dear Bill,
The Janolus from Senegal is J. praeclarus (Bouchet, 1975: pp 127-130, pl.1, fig.3, text fig. 5.). The original specimens were found on the bryozoan Bugula fulva at 22 metres depth, off Snake Island, which is close to Dakkar.
• Bouchet, P. (1975) Nudibranches nouveaux des cotes du Senegal. Vie et Milieu, 25(1): 119-132
Regards,
Richard Willan
richard.willan@nt.gov.au
Willan, R., 2003 (May 3) Re: Janolus from Senegal. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9845Thanks Richard,
The ceratal colour pattern seems very distinctive.
Best wishes,
Bill Rudman
Janolus sp. from Senegal
May 2, 2003
From: Marina & Patrice
Dear Bill,
Here is another beautiful find from Dakar, Senegal. Have you any idea which species of Janolus it is ?
These photos were taken by Patrice on the Tacoma wreck in April 1999, at a depth of 10m.
The first animal has something between rhinophores. Is it an egg-mass of a copepod parasite ?
Best wishes,
Marina Poddubetskaia
nembro@nembro.info
Patrice Petit de Voize
PdeVoize@aol.com
Dear Marina & Patrice,
I don't recognise this species of Janolus. The creamy subapical band on the cerata should make it identifiable if it has a name. The orange lump between the rhinophores is certainly pronounced. It is the caruncle or inter-rhinophoral crest which is one of the distinguishing features of the genus Janolus, and is considered to have some sensory function.
If anyone recognises the species, there input would be appreciated.
Best wishes,
Bill Rudman
