Re-Discovery of the "Extinct" earthworm
Fimoscolex sporadochaetus by researchers of Embrapa and American Universities
The earthworm
Fimoscolex sporadochaetus Michaelsen, 1918, cited on the oficial Brazilian list of extinct species (http://www.mma.gov.br/port/sbf/fauna/classe5c.html) was re-discovered on February 07, by George Brown (Embrapa-Ministry of Agriculture of Brazil), Samuel James (University of Kansas), Seana Davidson (University of Washington) and Nicolas Pinel (also Univ. Wash.). The researchers were looking for earthworms as part of two projects studying earthworms as environmental indicators (Embrapa-funded), and the diversity of bacterial symbionts living in earthworm nephridia (NSF-funded).
The earthworms were found living in the topsoil of an Atlantic Forest reserve in Itacolomi State Park, near Ouro Preto, Minas Gerais. The species is small (about 7 cm long), and rather similar to a widespread and well known species (the most common in Brazil),
Pontoscolex corethrurus (Müller, 1857). "At the moment of discovery, we joked around that it might even be the long-lost
F. sporadochaetus." However, we would only know for sure when it was looked at and dissected under the scope. "To our joy, when Samuel James compared the earthworms we collected to the original description, they matched perfectly!"
The species had been described from a single specimen in 1918, by J.W. Michaelsen, from a neighborhood of Belo Horizonte (Gorduras), Minas Gerais, Brazil. Fifty one years later, a few individuals were collected in a secondary forest near Conselheiro Lafaiete, South of Belo Horizonte, by the eminent Brazilian taxonomist Gilberto Righi (deceased). He complemented the original description with a few more details and a drawing of the earthworm's cocoons, in a paper published in 1971 [1].
Since then, the earthworm had not been seen again, and in 1998 it was listed as endangered in the Red List of Minas Gerais [2], primarily due to habitat destruction. The former collection sites in Belo Horizonte and near Conselheiro Lafaiete had become urbanized, and it was suspected that the earthworm was endangered of extinction.
In 2003, primarily due to the absence of sightings and the continued reduction in habitat, the species was considered extinct. However, it continued to live in at least one fragment of Atlantic Forest in the state of Minas Gerais, Brazil. It was only awaiting to be re-discovered by those willing to look hard enough for it (and lucky enough to find it).
Rare animals, particularly those that require digging to collect, such as earthworms, are not easy to find, and can often elude their potential capturers, as was posted recently in the message on the rediscovery of the Palouse worm in Idaho. The present case illustrates, once again, the need for more extensive fieldwork and further efforts to discover the range of this earthworm, that is, other natural habitats where it may still lie in hidding.
Habitat alteration certainly can be damaging to most native animals, including earthworms. However, fortunately there are still many fragments in the State of Minas Gerais, with suitable habitat, where the species may still exist. At least, for the moment, we know that the species is protected in a State Park.
Of the more than 300 known specis of earthworms in Brazil, 260 are native [3]. Of these, about 80% are known from only one (the type locality) or a few localities. In some cases this may be a case of real endemism and restricted distribution, but in others, it may only be an artifact of relatively small sampling effort. Some of these species may actually be endangered, but much further work is necessary to establish the true range of these species, and to adequately assess their present status of (extinction) danger.
For further information on the discovery, please access (in portuguese) the following site of Brazilian Government:
www.brasil.gov.br/noticias/ultimas_noticias/minhoca Posted by George G. Brown
Researcher Embrapa Soybean
March 11, 2006.
References:
[1] Righi, G. 1971. Sôbre alguns Oligochaeta brasileiros. Pap. Avul. Zool., S. Paulo. 25(1), 1-13.
[2] Righi, G. 1998. Oligoquetas. In: Machado, A.B.M., da Fonseca, G.A.B., Machado, R.B., Aguiar, L.M. de S. & Lins, L.V. (eds) Livro vermelho das espécies ameaçadas de extinção da fauna de Minas Gerais. Fundação Biodiversitas. Belo Horizonte, Brasil, pp. 571-583.
[3] Brown, G.G. & James, S.W. 2006. Biodiversidade, biogeografia e ecologia das minhocas no Brasil. In: Brown, G.G. & Fragoso, C. (eds) Minhocas na América Latina: Biodiversidade e ecologia. Embrapa, Londrina. in press.
