dejayM's picture

Spirorbis spirorbis

Observed: 22nd August 2010 By: dejayM
Biological Recording In ScotlandHighland Biological Recording GroupOrkney Biodiversity Records Centre
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Spirorbis plus

Here we have a few spiral worm cases on a dried seaweed frond. I suspect few people report them as they are quite small - here between 2 and 5mm (yes, peedie)
The first picture shows case upon case with most of them coiled sinistrally (from the mouth) - they are, almost certainly, Spirobis spirorbis.
But there are others, precious few, coiled the other way, that is dextrally.
I'd be very interested to see uploads of spiral worm cases which are sinistral - left handed and also other regional variations.
The second pictures show size, the rule is in half mm segments.
The third shows a variation in tube structure.
The last, bottom right, picture shows a spiral worm tube inside an old whelk shell. It definitely coils tuther way.

Species interactions

No interactions present.


scubamann's picture


I have agreed with your identification though my field book gives the Latin name as Spirorbis borealis, but it is an old book and names are often changed.

dejayM's picture


Yes, I got into 'trouble' using the other name.
Remember though, is is the name of the creature which produced this secreted structure.
Well done and thanks

ChrisMcA's picture

2-way spirorbis?

If Collins' Sea shore's right all spirorbis species coil same way, clockwise (& explain that they call them sinistral as it's "from the pt of view of the worm"). It also has 2 smaller dextral species, 1 on lobsters & 1 on limpets. (but maybe, like some shells, there's the rare exception?)

dejayM's picture

Direction of coil

Oh dear then, I wonder if I have sinistral mixed with dextral?
And yes, I cannot help but think this a very specialised business.
I have uploaded another picture, this is INSIDE a whelk shell - note that it coils, well, in the other direction!
I have a friend in Australia - I wonder the Southern Hemisphere the......

ChrisMcA's picture

Your 4th is, almost

Your 4th is, almost certainly,Janua pagenstecheri, (former Spirorbis p.) which accdg to collins seashore has 3 ridges on it, which you can see in high magnfcn, found lwr shore & sublittoral, & on "rock,stones, shells, & occasionally corallina". But if you search in google for spirorbinae you'll find a p.d.f. by the jrnl of marine biol, etc 1962, about S. corallinae & other spirorbis, & includes S. spirillum, another 'dextral' or anticlockwise species, "abundant & widespread sublittoral"

dejayM's picture


Thanks ChrisMcA - very helpful
I am on the case at the moment to find out MUCH more about these and there will be other postings this year.

dejayM's picture


I've just noticed the spelling mistake in the ID panel.
But I don't think correcting it to the WoRMS accepted will populate the panel with Wiki, NBN etc. In any case there are agreements.
I swapped dextral for sinistral in the text
Note my new posting here -

dejayM's picture

a mess

After a year of waiting I changed the ID to the old name (using the drop-down). But Wiki, EoL and NBN know the up-to-date one.