Obelia geniculata

Penny Martin is this an egg sac on Obelia geniculata ???

David Kipling Yes, looks like tiny nudi. Tergipes tergipes perhaps?

Penny Martin thanks .... didn't see the nudi ..... but will look out for it now but possibly need better eyes or a magnifying glass !!

David Kipling Very very hard to see in field - essentially impossible underwater, can sort-of do it if you see eggs by eye and then bring fluff to surface to look afterwards with a decent loops. Easiest under a microscope, these nudis are only 1mm long!

David Kipling http://www.habitas.org.uk/marinelife/species.asp?item=W14860 "Habitat: Feeds on several species of Obelia but especially Obelia geniculata (normally found on kelp fronds). The spawn consists of small white capsules."

Erling Svensen Out diving today. A lots, lots of Doto's, Gods know what kind of Doto? May be Doto coronata? Also quite many E. exiguus but they are very small now. In 2-3 weeks they become bigger (small is less than 4 millimeter - big is 5 - 7 millimeter).

Christian Skauge Beautiiiful! Woulf guess D. coronata but as you know they're almost impossible... :-)

Bernard Picton These are the Doto coronata which eat Obelia geniculata I think, Erling. We need to test, probably by sequencing a bit of DNA, to see if they are the same as the one you had the other day, which was eating Obelia dichotoma (probably). There are more or less identical, but bigger, animals eating Sertularia argentea, slightly darker ones eating Abietinaria abietina, and ones which look more or less the same eating several other hydroids. Carissa Shipman will like to see these.

Carissa Shipman It will be great to find out how genetically divergent these cryptic species are from one another. Still working on photographing them and then Terry will dissect them to look at their reproductive systems. Then I will get DNA! So much to do, but I must be systematic about it.

Erling Svensen The hydroid (best I could find). I will dive tomorrow and take some new ones. The tubercles are deep red in colour.

Bernard Picton Looks like an Obelia to me, perhaps Obelia dichotoma (if that's a single species as we currently use the name).

Erling Svensen If its Obelia, does it helps with the Doto?

Bernard Picton No-one really knows what the original Doto coronata is. The drawing in Gmelin, 1791, shows an animal on a Eudendrium or Obelia-like hydroid and it was cast up on the dutch coast. Carissa Shipman is working on Doto now, but they have to be one of the most difficult genera to sort out the species. DNA will help, but we still need to be able to see diffeerences between them; photographs, spawn and food will help sort that out I think. Doto coronata is the type species of the Genus Doto, so knowing which animal should bear this name is particularly important, especially if the genus needs to be split at some time in the future. I have one similar to this on the same hydroid, but will need to wait until I'm back at work next week to get the pictures. There are Doto on Obelia geniculata on kelp too, with bright pink spots. They might not be the same species.

Sarah Bowen Ah yes, I've got a Doto with bright pink spots from a dive up the Cleddau in Pembrokeshire. I'll dig it out later and post it, as I can't remember what it was found on (which won't necessarily be its food source if it's just out for a walk!)

Carissa Shipman Why do my comments keep disappearing on here?

Bernard Picton Carissa, there are three threads here on this specimen, photo, close-up and food. Also the thread with the most recent comment comes back up to the top so things don't stay in order. And the comments fold up so that only the most recent ones are showing until you click "View all x comments...". I see a comment from you on the full animal comments section, did you lose others?

Bernard Picton Also the search seems to work well - in Search this group (top RHS) enter Doto and hit return...

Christian Skauge I told you so :-) It works beautifully, and you can even combine search terms: Try 'doto erling' to see what he's been writing, and leave the others out ;-)

Penny Martin is this an egg sac on Obelia geniculata ???

David Kipling Yes, looks like tiny nudi. Tergipes tergipes perhaps?

Penny Martin thanks .... didn't see the nudi ..... but will look out for it now but possibly need better eyes or a magnifying glass !!

David Kipling Very very hard to see in field - essentially impossible underwater, can sort-of do it if you see eggs by eye and then bring fluff to surface to look afterwards with a decent loops. Easiest under a microscope, these nudis are only 1mm long!

David Kipling http://www.habitas.org.uk/marinelife/species.asp?item=W14860 "Habitat: Feeds on several species of Obelia but especially Obelia geniculata (normally found on kelp fronds). The spawn consists of small white capsules."

Penny Martin is this an egg sac on Obelia geniculata ???

Richie West Bit baffled by this wee trio, can anyone help? I thought the very dark nudi might be Flabellina pedata but both it and the tiny white processed one look like they are munching on red algae, not hydroids. I have other pics which clearly show the larger one has been eating seaweed. And what about the nudi on the right with orange-tipped processes that looks like it's eating Nemertesia?

Sarah Bowen Orange swollen tips to cerata suggests Eubranchus. Now I look again at the dark one with white tips they look that swollen but pointy Eubranchus sort of shape....

Sarah Bowen That nice Mr Picton says that there's a colour morph of Eubranchus farrani where the normal translucent white can be replaced by a purple-black or tawny orange hue. And they eat Obelia geniculata, which often grows on algae. Sound plausible?

Jennifer Jones I agree Sarah, and congrats to you Richie for a brilliant photo showing different colour morphs!

Richie West Thanks Sarah and Jen. Mystery solved!

Kerry Lewis Wowsers!

João Pedro Silva The dark ones are Eubranchus farrani. The smaller one has the characteristics of Eubranchus linensis (white tips of the oral tentacles and rhinophores) but E. farrani is so variable and the one on the left has also white tips of the rhinophores and oral tentacles... but definitely not a Janolus.

David Kipling Just so I'm clear ... there are three nudis here. [1] Biggest, far left, dark with white tips. [2] Middle sized, right hand side, orange tips. [3] Smallest one near middle/bottom, grey with white tips. Which are you saying is which João Pedro?

João Pedro Silva [1] and [2] E. farrani; [3] E. linensis OR E. farrani.

João Pedro Silva Check my latest of E. linensis (much more common than E. farrani here): http://www.flickr.com/photos/jpsilva1971/6919061696/

David Kipling I don't think we've ever had UK records for E linensis (according to NBN and Habitas).

David Kipling To me, [3] has the "feel" of a baby version of [1]. Richie West ... could you post a cropped version so we can see the little one in more detail please?

João Pedro Silva That's why I'm in doubt regarding [3]. I also think it's more likely to be E. farrani. But there are records of E. linensis as far north as The Netherlands.

Jennifer Jones I think all three are E. Farrani