Garveia nutans

Tony Gilbert About 30mm, Menai Straits, 10m. I am wondering whether this is a C. verrucosa, as it has a number of the characteristics, such as distinct orange cerata, and very grainy, and there are a couple of white spots on the body (not seen on this image, but another I have). C. brownii are less orange, more red, or orange-red and perhaps not as grainy. It was the different colouration that drew my attention. I had seen and photographed several C. brownii on the same dive and in the locale. The rhinophores are not ringed, but slightly ribbed, and have some white markings - as do the propoidal tentacles; the cerata have white rings at the end, with opaque quartz coloured tips.The tail has a white stripe down its centre. https://www.facebook.com/media/set/?set=a.236433703157387.57884.100003722780643&type=1#!/photo.php?fbid=239389106195180&set=a.236433703157387.57884.100003722780643&type=3&theater

Bernard Picton Coryphella rufibranchialis. I just rescued this from synonymy after seeing photos from Erling Svensen and Jorn Ari but it will need to be published I suppose, not that it needs a paper... The white on the long tail is diagnostic... Interesting that it seems to be on Garveia nutans; that is worth following up as there is plenty of that hydroid in Strangford Lough where C. rufibranchialis is common. They certainly swap onto Tubularia indivisa when they get big, but I noticed the small ones were in a different place and presumably eating a smaller hydroid. Nice.....

Tony Gilbert Thanks Bernard, I probably wouldn't have id'd this as C. verrucosa rufibranchialis. I've another shot that clearly shows two white spots at the base of the first cerata, and better image of the Garveia nutans hydroids. The difference beteen this and the parent is that the parent has a long tail with a broken/spoted white line, right? Would you also say, if this species is found on Garveia nutans, then that would be diagnostic of C. rufibranchialis or does its parent eat G. nutans as well or just T. indivisa? https://www.facebook.com/media/set/?set=a.236433703157387.57884.100003722780643&type=1#!/photo.php?fbid=240047172796040&set=a.236433703157387.57884.100003722780643&type=3&theater It was certainly found in a very strong tidal stream, which was starting to run quite badly when I was photographig this. It was on The Cable dive at Menai Straits, the area between the cable and Ynys y Moch island - at the reef start around 10m. Garveia nutans is quite prevalent here as is T. indivisa.

Bernard Picton Tony - you misunderstand me. You need to read up on the biological species concept. I'm saying that there are two species - C. verrucosa and C. rufibranchialis. It is particularly important as C. rufibranchialis is the TYPE species of Coryphella. http://evolution.berkeley.edu/evosite/evo101/VA1BioSpeciesConcept.shtml

Bernard Picton http://en.wikipedia.org/wiki/Type_species

Tony Gilbert Ok, thanks Bernard, yes more reading!

Tony Gilbert I usually check WoRMS: http://www.marinespecies.org/aphia.php?p=taxdetails&id=162691 Also, I found another web-record from the Straits, taken Sept 2011, which is reassuring to know others are finding them as well: www.conchsoc.org/node/6073

Brendan Oonk I'm looking for a reference to the maximum size of Doto sarsiae. Can anyone help me?

Carissa Shipman Picton's paper from 1992. Genetic divergence and cryptic speciation in two morphs of the common subtidal nudibranch Doto coronata(Opisthobranchia: Dendronotacea: Dotoidae) from the … The size of the animal should be in there.

Carissa Shipman I need some D. sarsiae for my research. It is the last species within the complex that I need. If you have access to live specimens of D. sarsaie, let me know.

Brendan Oonk Would be great if i would find one. Would be my first :) (Sorry Carissa.....)

Brendan Oonk You were right: the size is in there. Thanks!

Carissa Shipman No problem. I am studying these little buggers for my Masters. It is quite a challenge, but I am not giving up.

Ian Smith Hi Brendan, it's very like Doto coronata. I wouldn't have had the confidence to identify those I found or its prey without Bernard's help. To find it, I'd look for Sarsia exima and Garveia nutans, otherwise it's like spijkers op laag water zoeken . I found several on G. nutans on a small stone at extreme low water spring tide. They ranged from 2mm (assumed identity as with several adults - impossible to id in isolation) to 8.5mm length. One helpful feature I discovered was prominent head crests running forward from the rhinophores - D. coronata lacks them. Images of my finds, including close up of crests, G. nutans and link to Bernard's image of S. exima are at http://www.conchsoc.org/spaccount/Doto-sarsiae I stated max size as 9mm to just top my 8.5mm specimen, but possible it could go bigger than my experience. Cheers Ian