nomenclature
Type specimens and live specimens
21-08-2009 16:12
Perhaps did you hear about the discovery of
the
Galápagos Pink Land
Iguana
early this year? This week it was formally described
as a new species this week:
Conolophus
marthae
Gentile & Snell, 2009.
The interesting thing about their description is that their holotype is still alive. The International Code of Zoological Nomenclature states that “where the holotype or syntypes are extant specimens, by a statement of intent that they will be (or are) deposited in a collection and a statement indicating the name and location of that collection” (art. 16.4.2). There is some debate as to whether living specimens are allowed as types if they have not been deposited in a museum collection.
I find this point interesting, as the two living specimens I have in my lab belong to a new species, yet to be described. Or rather, only one is still alive since I sacrificed the other for anatomical research. Thus, while in this case the holotype is already dead and the shell and fixed body have been incorporated in the collection, the paratype is still living.
The existence of living (holo)types have stirred up a debate (Dubois, 2009, Dubois & Nemésio, 2007; Donovan, 2008, 2009; Nemésio, 2009). Dubois (2009) points out that the wording of the Code is ambiguous and does not clearly prohibit the description of a species with living type specimens. He also makes clear that the description of the Galapagos Pink Land Iguana is deliberately based on a living holotype, following after a discussion amoung scientists. The case acts thus as a test case for a provision of the ICZN and will likely become a textbook case in the future. He argues that not fixing a holotype in the collection, thus e.g. adding to the threat of extinction of the population, is sending out the wrong message from a conservationist point of view. To progress our knowledge we would always need one specimen in a scientific collection for reference, also for endagered species of which few specimens are known. For this reason, Dubois & Nemésio (2007) and Nemésio (2009) have argued for a rephrasing or amendment of the Code, making it obligatory to deposite preserved specimens of any taxon to be described.
Donovan (2008, 2009) rejects this strict reasoning and argues that one shouldn’t have to wait on actions by the ICZN (which may take considerable time) to describe a new taxon. He further sees the measures taken by Gentile & Schnell, to place a passive transponder in the holotype of the pink iguana enabling its localization, as an innovation in taxonomy. For the sake of brevity I skip here the debate on ethical questions (see Donovan 2008, 2009; Nemésis, 2009).
Suffice to say that the debate hasn’t been closed yet and awaits a decision by the Commission.
My living snail will stay alive for a while, I hope. It will be described as a new species later this year. Having read the story of the Galápagos pink iguana, I could even refer to the *living* paratype in the paper indicating that it is in the lab of the museum where it will be deposited after its death. Alive or dead, I still have a choice. If the ICZN doesn’t change it’s mind too quickly...
References:
Donegan, T.M., 2008. New species and subspecies descriptions do not and should not always require a dead type specimen. -Zootaxa 1761: 37-48.
Donegan, T.M., 2009: Type specimens, samples of live individuals and the Galapagos Pink Land Iguana. - Zootaxa 2201: 12-20.
Dubois, A., 2009: Endangered species and endangered knowledge. Zootaxa 2201: 26-29.
Dubois, A. & Nemésio, A., 2007. Does nomenclatural availability of nomina of new species or subspecies require the deposition of vouchers in collections? - Zootaxa 1409: 1-22.
Gentile, G. & Snell, H., 2009: Conolophus marthae sp.nov. (Squamata, Iguanidae), a new species of land iguana from the Galápagos archipelago. - Zootaxa 2201: 1-10.
Nemésio, A., 2009: On the live holotype of the Galápagos pink land Iguana, Conolophus marthae Gentile & Snell, 2009 (Squamata: Iguanidae): is it an acceptable exception? - Zootaxa 2201: 21-25.
The interesting thing about their description is that their holotype is still alive. The International Code of Zoological Nomenclature states that “where the holotype or syntypes are extant specimens, by a statement of intent that they will be (or are) deposited in a collection and a statement indicating the name and location of that collection” (art. 16.4.2). There is some debate as to whether living specimens are allowed as types if they have not been deposited in a museum collection.
I find this point interesting, as the two living specimens I have in my lab belong to a new species, yet to be described. Or rather, only one is still alive since I sacrificed the other for anatomical research. Thus, while in this case the holotype is already dead and the shell and fixed body have been incorporated in the collection, the paratype is still living.
The existence of living (holo)types have stirred up a debate (Dubois, 2009, Dubois & Nemésio, 2007; Donovan, 2008, 2009; Nemésio, 2009). Dubois (2009) points out that the wording of the Code is ambiguous and does not clearly prohibit the description of a species with living type specimens. He also makes clear that the description of the Galapagos Pink Land Iguana is deliberately based on a living holotype, following after a discussion amoung scientists. The case acts thus as a test case for a provision of the ICZN and will likely become a textbook case in the future. He argues that not fixing a holotype in the collection, thus e.g. adding to the threat of extinction of the population, is sending out the wrong message from a conservationist point of view. To progress our knowledge we would always need one specimen in a scientific collection for reference, also for endagered species of which few specimens are known. For this reason, Dubois & Nemésio (2007) and Nemésio (2009) have argued for a rephrasing or amendment of the Code, making it obligatory to deposite preserved specimens of any taxon to be described.
Donovan (2008, 2009) rejects this strict reasoning and argues that one shouldn’t have to wait on actions by the ICZN (which may take considerable time) to describe a new taxon. He further sees the measures taken by Gentile & Schnell, to place a passive transponder in the holotype of the pink iguana enabling its localization, as an innovation in taxonomy. For the sake of brevity I skip here the debate on ethical questions (see Donovan 2008, 2009; Nemésis, 2009).
Suffice to say that the debate hasn’t been closed yet and awaits a decision by the Commission.
My living snail will stay alive for a while, I hope. It will be described as a new species later this year. Having read the story of the Galápagos pink iguana, I could even refer to the *living* paratype in the paper indicating that it is in the lab of the museum where it will be deposited after its death. Alive or dead, I still have a choice. If the ICZN doesn’t change it’s mind too quickly...
References:
Donegan, T.M., 2008. New species and subspecies descriptions do not and should not always require a dead type specimen. -Zootaxa 1761: 37-48.
Donegan, T.M., 2009: Type specimens, samples of live individuals and the Galapagos Pink Land Iguana. - Zootaxa 2201: 12-20.
Dubois, A., 2009: Endangered species and endangered knowledge. Zootaxa 2201: 26-29.
Dubois, A. & Nemésio, A., 2007. Does nomenclatural availability of nomina of new species or subspecies require the deposition of vouchers in collections? - Zootaxa 1409: 1-22.
Gentile, G. & Snell, H., 2009: Conolophus marthae sp.nov. (Squamata, Iguanidae), a new species of land iguana from the Galápagos archipelago. - Zootaxa 2201: 1-10.
Nemésio, A., 2009: On the live holotype of the Galápagos pink land Iguana, Conolophus marthae Gentile & Snell, 2009 (Squamata: Iguanidae): is it an acceptable exception? - Zootaxa 2201: 21-25.
"Bulimulidae" or the confusion of progress
26-12-2006 21:16
Taxonomy is an odd
science and too often considered as old-fashioned and
out-dated. Especially now with the molecular genetic
studies, I hear often complaints from fellow
researchers at Naturalis (Leiden) that they
unsuccesfully applied for funding of projects. The
"modern" genomics-related proposals won....
However, what people tend to forget is that you can't be sure of the organism you study untill you are able to identify it properly. And that is what taxonomists are for.
When I concluded my revision of the Bulimulidae in 1979 life was fairly simple. Although the data did not allow to pinpoint the relationships between the several groups in detail, I was convinced at that time that the Bulimulidae as a whole were a solid group. In my view it consisted of 5 subfamilies: Bulimulinae, Amphibuliminae, Odontostominae, Orthalicinae and Placostylinae. Now, more than 25 years later, progress has been achieved and things are quite different.
First of all there is a nomenclatural issue. Bulimulidae as a family name appears to be pre-occupied by the Orthalicidae. And as some subfamilies have been raised to family rank, the group is now referred to as Orthalicoidea.
Furthermore the "Bulimulids" now also have an African offspring. Dai Herbert (Natal Museum) told me last year that he concluded that the genus Prestonella belongs to this group, as he will show by DNA-studies (still to be published).
Although over the years some people have worked on the group, relationships are still rather unclear. My suspicion is that a re-evaluation of the relationships at generic level, on the basis of DNA research, will reveal some truely surprising results. Sort of confusion for people interested in "Bulimulidae".... the few who are.
However, what people tend to forget is that you can't be sure of the organism you study untill you are able to identify it properly. And that is what taxonomists are for.
When I concluded my revision of the Bulimulidae in 1979 life was fairly simple. Although the data did not allow to pinpoint the relationships between the several groups in detail, I was convinced at that time that the Bulimulidae as a whole were a solid group. In my view it consisted of 5 subfamilies: Bulimulinae, Amphibuliminae, Odontostominae, Orthalicinae and Placostylinae. Now, more than 25 years later, progress has been achieved and things are quite different.
First of all there is a nomenclatural issue. Bulimulidae as a family name appears to be pre-occupied by the Orthalicidae. And as some subfamilies have been raised to family rank, the group is now referred to as Orthalicoidea.
Furthermore the "Bulimulids" now also have an African offspring. Dai Herbert (Natal Museum) told me last year that he concluded that the genus Prestonella belongs to this group, as he will show by DNA-studies (still to be published).
Although over the years some people have worked on the group, relationships are still rather unclear. My suspicion is that a re-evaluation of the relationships at generic level, on the basis of DNA research, will reveal some truely surprising results. Sort of confusion for people interested in "Bulimulidae".... the few who are.