Topic: Rhizostoma octopus/pulmo

Hi Chris,

I have recently come across a problem with the Barrel Jellyfish (Rhizostoma pulmo) and the apparent differing understanding of the relationship between this species and Rhizostoma ocotpus (which currently the UKSI shows as being a synonym of R.pulmo).

The issue began on iNaturalist as can be seen from the discussion on the following link:  https://www.inaturalist.org/observations/32489790.  Here the user on iNat (wyattp11) notes that the international understanding is now that R.pulmo and R.octopus are separate species with differing distributions


wyattp11 commented:
Yes, that is all old, incorrect information. There has been considerable work done recently, the life cycles of both have been independently described:
https://link.springer.com/article/10.10 … 006-0594-8
https://link.springer.com/article/10.10 … 011-1730-7

And even more recently it was shown that R. octopus may actually comprise several species or sub-species:
https://academic.oup.com/biolinnean/art … 82/2440366

A third species, R. luteum is now recognized which was also synonymized into R. pulmo previously. This species separates the two around the Iberian Peninsula.


WoRMS seems to support this - see here:  http://www.marinespecies.org/aphia.php? … tributions and  http://www.marinespecies.org/aphia.php? … ;id=152203

Thanks for your help - it looks like Rhizostoma pulmo will need to be split once more.


Steve J. McWilliam


Re: Rhizostoma octopus/pulmo

OK, I think that as the name has remained distinct and wouldn't have been used to enter records for pumilio, I will just restore it to it's own taxon which will mean that any records for it will follow it.

Chris Raper, Manager of the UK Species Inventory, Angela Marmont Centre for UK Biodiversity,
Natural History Museum, Cromwell Road, London, SW7 5BD.  (tel: 020 7942 5894)
also Tachinid Recording Scheme (http://tachinidae.org.uk/)