by Piter Kehoma Boll
Biogeography, as you may know, is the study of the distribution of species or ecosystems through the planet. The knowledge which comes from biogeographical surveys is valuable information for other areas, like ecology, evolutionary biology, geology and paleontology, as well as for conservation purposes. Knowing the distribution of a species may help to determine places of higher priority for conservation, as well as helping to trace an evolutionary pathway or even to determine an ancient geological event.
Despite all this advantages coming from biogeographical studies, many species have a sparse distribution record, or don’t have any at all. That’s more usual concerning “less attractive” groups, like, for example, worms or mosses, which don’t have many researchers interested in them.
I will give here an example among a species I work with. It’s a land planarian, of course; what else could it be? Anyway, the species I’m talking about is called Geoplana marmorata. Here you can see a picture of it:
G. marmorata was described in 1857 by Schultze & Müller based on material coming from Blumenau, a city in the state of Santa Catarina, southern Brazil. Later, Graff, in 1899, misidentified it as a variety of Geoplana rufiventris, another species described by Schultze & Müller in the same paper as G. marmorata. This misidentification happened probably due to the specimens examined by Graff being old ones which were kept too much time in a preservative medium, probably ethanol, making them lose their original color as when alive.
About 50 years later, in 1959, C. G. Froehlich corrected this mistake and also expanded its distribution for a new location, Rio do Testo, not that far from Blumenau. In 1967, C. G. Froehlich again expanded its known distribution to include Argentina.
There are no further publications concerning the distribution of G. marmorata, except for a paper by E. M. Froehlich, from 1978, about a Chilean species, G. caleta, which resembles G. marmorata both in external and internal morphology, but the minor differences and the great distance separating both groups seem to point to different species, though probably closely related phylogenetically.
Anyway, so concerning only what’s now found through papers, G. marmorata is only know to happen in Argentina and the Brazilian state of Santa Catarina. Well, here I say that its distribution is far greater.
Despite not being recorded in any species survey in forest remains of Rio Grande do Sul, Brazil’s southernmost state, G. marmorata is indeed found there. We, researchers from Instituto de Pesquisa de Planárias, Unisinos, know this species very well since it is found very frequently in urban environment in the metropolitan area of Porto Alegre, as well as in Santa Maria, a city in the center of the state.
I was kind of shocked as I figured out that there are no publications regarding its presence in Rio Grande do Sul. This just made me wonder about how much scientists know and, as it seems so obvious and natural, they don’t publish it, so retaining essential knowledge, which could be so useful to other researches, simply because of some lack of attention.
This has motivated me to write a paper updating the distribution of land planarian species from Rio Grande do Sul as soon as I have time, based on our protocol records at Instituto de Pesquisa de Planárias. And as a final request, I ask to those who work with research to pay attention to those subjects, so that they don’t get neglected as much.
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Froehlich, C. G. 1959. On Geoplanids from Brazil. Boletim da Faculdade de Filosofia, Ciências e Letras da Universidade de São Paulo, Série Zoologia, 22, 201-265
Froehlich, C. G. 1967. A contribution to the zoogeography of neotropical land planarians. Acta Zoologica Lilloana, 23, 151-162
Froehlich, E. M. 1978. On a collection of Chilean landplanarians Boletim da Faculdade de Filosofia, Ciências e Letras da Universidade de São Paulo, Série Zoologia, 3, 7-80
Graff, L. v. 1899. Monographie der Turbellarien. II. Tricladida Terricola. Engelmann, Leipzig, 574 p.
Schultze, M., & Müller, F. 1857. Beiträge zur Kenntnis der Landplanarien. Abhandlungen der Naturforschenden Gesellschaft zu Halle, 4, 61-74