constantlycurious's picture

Unknown egg sac on the seaweed Chondrus crispus

Observed: 26th June 2013 By: constantlycurious

Single egg sac 2 mm a cross/1/4 mm thick on exposed Chondus crispus (Carrageen) seaweed. South East England. On other pieces of the same seaweed there were other egg sacs laid in rows of up to 7, one behind the other.
Great site. Never used before. Hopefully somebody can help id this. Thanks.

Species interactions

No interactions present.


ChrisMcA's picture

It's the egg case of a netted

It's the egg case of a netted dog whelk, but which species? Have you still got the case or did you measure it?

gramandy's picture


..only 2mm as in the description not 5mm.

ChrisMcA's picture

I'm very interested in these

I'm very interested in these flask-shaped eggcases as there's 2 species which are supposed to differ in size (although both are small)

ChrisMcA's picture

I guess you didn't keep it;

I guess you didn't keep it; but I'm assuming yours is about 5mm high. see eg, with several views showing the size, & also or
But if it was 2mm high that'd be really interesting as that's the height of thick-lipped egg cases & there are no photos of them at all either on the net or in books

gramandy's picture

and could still... L.obtusata at this size.

ChrisMcA's picture

I see Gramandy you've now

I see Gramandy you've now agreed to my ispot ,put up so constantlycurious could see the scale of these things; & I see you'd actually agreed to dejays periwinkle eggs (as did I), so in your ID here instead of the incredible link "we have a string of comments" (what kind of help is that?) you could have given the link, which shows them as eggs in a blob of jelly, totally different from this flask shape. So based on your ID & further comment I believe a retraction is called for

ChrisMcA's picture

Even as a comment your id

Even as a comment your id would be totally uncalled for! based on any pictures? Based on "a string of comments going around"? have you seen what they're commenting on? Have you bothered to check the links I gave?

dejayM's picture

Incredible links

That Graham is trying hard to establish the correct ID is admirable. Teasing and challenging the merest tiny detail is good for iSpot, certainly for me.
Chris is right, this is a capsule, unlike the ones pertaining to Flat Ps. which are all clearly little 'blobs'.
As for scale here Graham, sometimes it's important, often not - this one IS and you've said 2mm so I infer that it might be the same (or near) height.
That might make it Nassarius incrassatus (WoRMS)

ChrisMcA's picture

It would be if he was.How

It would be if he was.How exactly is a totally false ID with no link at all to check it out with trying hard!!!

ChrisMcA's picture

That is rubbish dj, he's

That is rubbish dj, he's given an ID based on nothing whatever, which is irresponsible; in what away is this flask similar to those periwinkle eggs. As a result we're stuck with a totally false ID. & we aren't sure of the scale; & NB constantlycurious states there were others laid in rows which Lebours specifically says incrassatus doesnt do

gramandy's picture

getting rather tired...

...of insulting comments - any more and I will report these as inappropriate. I missed the comment about laid in a row up to 7 and therefore I have agreed to your ID. Perhaps we can put all this to rest now.

ChrisMcA's picture

thank goodness

thank goodness

ChrisMcA's picture

constantlycurious, when I

constantlycurious, when I said netted dog whelk egg case initially I meant hinia species,as there's no english for the genus; & a further complication is the genus has 2 names, so there's more of the same eggs under reticulatus. [But NB I note your's is the biggest of all the photos on Ispot]
On the other hand I can't show any incrassatus eggs as there aren't any anywhere on the net. So see what youthink of all these links; eg is the scale of right. the lack of any other evidence is why I've ID'd it as hinia reticulata; but if you're sure it's 2mm please get some more photos with scale

dejayM's picture


Fergus, if you do come back to this, your first and EXCELLENT post. Then don't fret too much about the not-very-light (slightly unpleasant) banter here.

A decent ID will come, with more agreements.
You should go to Edit and re-select the group to Invertebrates, that way a few more people will see this post and offer wisdom or agreements.

JoC's picture

Nassarius egg cases

I just read this in A Student's Guide to the Seashore, Fish & Fish, says of Nassarius,(as the currently accepted genus name for these two netted dog whelks) which may be of interest.

N. incrassatus: 'egg capsules laid in clusters on hydroids, bryozoans & Zostera, each capsule containing 50-80 eggs'
N. reticulatus: 'egg capsules are laid in rows on Zostera, on red seaweeds & sometimes on hydroids and stones. Each capsule contains up to 300 or more eggs.'

This one is on a red seaweed, so I'll just start counting the eggs now......


dejayM's picture

Old name

Yep (where have you been Jo?)
There are well over 200 and it's on Chondus crispus..
If we are to believe Fish & Fish (and we should) then there is no doubt.
The Haywood and Ryland Handbook appears to have no description of the egg capsules.
I obviously now need to buy the new F&F.
We might now accept then that the WoRMS preferred Nassarius reticulatus (Netted Dog Whelk) is the owner of this capsule.
The only question is, should we agree with the old name? I have and so, I see, has Graham.
I'd say Furgus (constantlycurious) has described this incredibly well.

ChrisMcA's picture

Yes but what about the 2mm

Yes but what about the 2mm across; what sort of camera would give such a large photo?

dejayM's picture

millimetres and lenses

Well a few things there. For some reason you have deduced a height of 5mm in your ID but I inferred that it might be the same (or near) height (from my 'Incredible Links').
Graham was quick to remind us that 2mm is in the original EXCELLENT description.
That, generally, I trust your judgement (Chris) regarding IDs and Jo's summary style as in 'Nassarius egg cases' allows me to support your ID.
There's not much more until reasoning changes - that is likely to come from you or Jo - so when it does I'll join in again.
As for the camera. constantlycurious has cropped a much larger photo. The egg-case image is just on the verge of degrading because of enlargement. My small pocket camera (Lumix TZ) is capable of just such a feat. My guess is that constantlycurious has used a macro lens on a decent DSLR. My DSLR (which I don't use for field photos) is capable of producing 1:2 ratio (half life size) so would easily show the eggs in a 2mm capsule - see the original images in my -taken with my pocket TZ9