Roan Stoel Two pictures taken today in he Oosterschelde, Netherlands. I could use some help identifying the two. We're thinking that they might be eubranchus rupium or tergipes tergipes.
Jørn Ari Need help with ID.
Size: 2mm , Depth: 5m, Watertemp: 6 degrees Celcius, Divesite: Munkholmbroen - Denmark
Jerry Shine I'm not familiar with the nudibranchs in Denmark, Jorn, but if I saw that in the western Atlantic, my first guess would be Eubranchus exiguus.
Jørn Ari Thanks Jerry
Brendan OonkEubranchus rupium On the back of the animal you can see the zig-zag patern. The tips of the cerata are blue-ish white.
Jørn Ari Thanks Brendan
Christian Skauge Agree with Brendan on this one :-)
Christian Skauge A little something on Eubranchus rupium from Jussi Evertsen and Torkild Bakken's blog Nudibranchia.no (english text at the bottom). This species was recently made official in Norway.
Bernard Picton The cerata are unusually swollen, but I see the green digestive gland in the body. I'm not certain of that identification, though, but I've not seen this species alive myself.
Brendan Oonk I agree cerata are somewhat swollen, but what else could it be? I know of no other Eubranchus with blue-ish white tops of the cerata and with the green zigzag line (digestive gland) showing on its body.
Bernard Picton The one thing I've learned is never to assume something is the nearest thing. If it has some differences then it could easily be an undescribed species.
Jørn Ari http://www.nudibranchia.dk/eubranchus-rupium-aeolid.html
Tony Gilbert I'd agree with that synopsis Bernard - have fallen down that pit plenty of times!
Arne Kuilman I am going to search for them tomorrow!
Tony Gilbert Ah, the joys of Grevelingen Meer and its reef balls! I know it usually has a higher-salinity, because of the sluijs, so can it actually get down to a temperature of 0C? Perhaps at a certain depth then. Last time I dived it it was 12C (June) to about 12m, then around 5-8C at 24m in darkness passed the reef balls and to a platform.
Marco Faasse Tony Gilbert, the Grevelingenmeer is almost stagnant, indeed with stratification in winter and summer. Because of this, and because of little exchange with the North Sea, surface water temp in winter can get as low as 0 (or minus 1?) degrees C, and in summer once 26 degrees has been measured! Certain species, such as dead man's fingers, you won't find in the upper 12 m in the Grevelingenmeer.
Marco Faasse I suppose the thermocline is just above the zone where dead man's fingers occur. Everything above the thermocline I consider as surface water; 0 degrees C. at 10m seems perfectly credible to me.
Tony Gilbert Rene, I was just wondering about the physics of it, salinity, density of water etc. They don't open the gates often, prob. unheard of these days I guess.
Arne Kuilman I heard from a different divers ten's of these can be found in a couple of weeks at St. Annaland if people want to search them elsewhere as well. They eat Laomedea longissima and Obelia sp.
Brendan Oonk Long rhinophores with orange bands, blue-ish white at the top of the cerata, digestive tract is visible as zigzag pattern on the back. All characteristics of E.rupium
Erwin Koehler Nudipixel places it in the genus Nudibranchus Martynov, 1998,
with the identification verified by Alexander Martynov (Zoological Museum of Moscow State University), Nudi Pixel expert...
Brendan Oonk Nudi pixel also uses the name Eubranchus rupium. WoRMS only uses Eubranchus rupium ..... And the winner is.....???
Brendan Oonk Long rhinophores with orange bands, blue-ish white at the top of the cerata, digestive tract is visible as zigzag pattern on the back. All characteristics of E.rupium
Erwin Koehler Nudipixel places it in the genus Nudibranchus Martynov, 1998,
with the identification verified by Alexander Martynov (Zoological Museum of Moscow State University), Nudi Pixel expert...
Brendan Oonk Nudi pixel also uses the name Eubranchus rupium. WoRMS only uses Eubranchus rupium ..... And the winner is.....???
