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Topic: Taxon - use of seg. and agg.

Hi all

I'm trying to map some records I've received from a Recorder 6 system into MapMate and amongst which are some mollusc records which have the taxon suffix "seg." I have not seen used before.  I have got as far as working out this is used to show a segregate of a wider aggregate group. 

For example, I have aggregate and segregate taxa for species:

Carychium minimum agg.
Carychium minimum seg.

Vitrea crystallina agg.
Vitrea crystallina seg.

Would I be right in thinking that the segregate is being used in the same way as sensu stricto? i.e. it segregates a single species? 

I know that there is binomial form for each of these species in Recorder 6 as well, so wanted to check that the segregate was not a narrower grouping of species in the wider aggregate.

I appreciate this is not strictly a Recorder 6 related question!

Best wishes

Neil Fletcher
Bucks & Milton Keynes Environmental Records Centre

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Re: Taxon - use of seg. and agg.

my understanding is the Agg. and Seg. in Recorder have the same meaning as sensu lato and sensu stricto, and many years ago (in the time of Recorder 3, there was an intention to standardise these suffixes, i.e. all agg/seg or all s.l/s.s. but it never happened so there are a mixture of terms all basically meaning the same thing!

I await to be corrected by Chris Raper, but he might not be watching this thread, as this is really a species dictionary query!

Craig

Craig Slawson
Staffordshire Ecological Record

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Re: Taxon - use of seg. and agg.

Many thanks Craig, I will confirm directly with Chris.

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Re: Taxon - use of seg. and agg.

I have noticed that "seg." does tend to get used quite a lot for molluscs and as it isn't my group I'm not 100% sure of the nuances. But after reading up on this I think the taxon concepts only get created when someone proposes a split in an existing taxon, where they suspect they have found a cryptic species. The original concept is the "agg." and the split concept is the "seg." but when taxonomic consensus arrives at a decision then they might upgrade the "seg." to a new named species (I presume with a different binomial) and the "agg." would remain to contain records of the pre-split situation. The "seg." effectively becomes a junior synonym of whatever the new species is called.

This is very similar to how taxonomists use "s.l." and "s.s." but biological recorders often use "agg." to denote a taxonomic concept that contains very close species that are unidentifiable without specialist techniques but where they might want to take the records anyway at this less-precise level.

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/)