"(morpho)" species?

Doug Yanega dyanega at MONO.ICB.UFMG.BR
Thu Jan 7 11:19:19 CST 1999


Peter Rauch wrote:

>I suppose the one point further to make is that the dilemma of not being
>able to identify those "real" species (as you say, whatever definition
>that entails), when doing the biodiversity assessments, and having to
>"settle for" morphospecies, leads to weaknesses in the diversity
>assessments (but, are those weaknesses of the same consequence as the
>one you raised for diversity studies which use higher level
>categories...?  I'd suspect not, but as long as we're critiquing
>diversity studies...).

I don't think it's precisely the same sort of weakness, but it *can* be
similar, since the higher-taxon problem is one of fluctuating group
boundaries - and if one changes one's idea of species limits, then this
*could* happen. Of course, the likelihood of this affecting the diversity
data for a *single* sampling point is extremely small, since I don't think
one often encounters cryptic species that are sympatric (at least I haven't
heard of this; maybe I just need to be corrected). Problems with simple
mistakes in morphospecies assignment (due to non-experts doing the IDs) are
a different matter, and hard to avoid in entomological studies, at least,
though my impression is that such mistakes are actually more often
*conservative* errors (such as counting polymorphic or sexually dimorphic
species as MORE than one morphospecies). A student here did a small study
of a mite community, and discovered after the material was IDed by an
expert that he had only half as many species as he'd counted in his
morphospecies analysis, due to the presence of males, females, and various
nymphal stages of the same species. Other studies by the same and other
students here routinely count insect larvae as separate from adults in the
same samples, simply because they have no way to confirm associations. So
yes, I fully agree that working with morphospecies entails its own
assumptions and risks. Risks which could be minimized if we had a greater
number of competent taxonomists involved in such studies, but we've
lamented this point here before... ;-)

Peace,

Dr. Douglas Yanega
Depto. Biologia Geral
Univ. Federal de Minas Gerais
Caixa Postal 486
30161-970 Belo Horizonte, MG, BRAZIL
(31)-499-2579




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