Agriculture Reference
In-Depth Information
Conservation of the Endemic
Species in the Carpathians..........................................139
Octodrilus
includes a quite well-defined group of lumbricid earthworm species and has
a relatively simple history. rley (1895) established the genus
The genus
Octodrilus
for lumbricids based on
eight widely paired rows of setae, regardless of pigment. V. Pop (1941, 1948), for phylogenetic
considerations, modified the diagnosis of the genus, keeping in it only species without red pigment.
Omodeo (1956) divided the genus into the subgenera
Octolasion
based mainly on
the number of spermathecae; these subgenera were raised to the rank of genera by Bouch (1972).
Zicsi (1986), based on the position of the male pores, divided the latter genus into two genera,
Octolasium
and
Octodrilus
Octodrilus
and
Octodriloides
.
In this concept,
Omodeo (1956) includes medium-size to very large earthworms without
pigment or pigmented in hues of gray or brown, with widely paired setae, four pairs of seminal
vesicles, and five to eight pairs of spermathecae in the genus
Octodrilus
. The clitellar organs are
very constant and characteristic of the species.
Most
species have relatively small distribution areas in central and eastern Europe
or in North Africa. Endemic species occur in the Alps, Carpathians, and Dinara Mountains. A very
few species, such as
Octodrilus
Octodrilus complanatus
, are widely distributed in Europe.
is difficult to study because of many closely related species,
often improperly described, with overlapping diagnostic characters. At least 54
However, the genus
Octodrilus
Octodrilus
species
รพ
have been described to date (Zicsi and Pop 1984; Pop 1989:
Mrsic
1991). In the Romanian
Carpathians, 11 species and 7 subspecies are known (Pop 1941, 1948, 1973; Zicsi and Pop 1984;
Pop 1991) (
Table 7.1
,
Figure 7.1
).
species. They occur
mostly in remote mountain regions, mainly on limestone soils, in which their sampling is very
difficult. Hence, studies of
Very little is known about the general biology and ecology of
Octodrilus
species have been neglected. During 20 years of research in
the Carpathians, in different projects studying the structure of mountain ecosystems, we have
collected many samples of earthworms belonging to
Octodrilus
species. Some of the local earth-
worm populations, especially those in the Apuseni Mountains, raised difficult taxonomic problems,
particularly concerning the variability of certain characters. Taxonomic studies have led to more
theoretical ones, such as of the patterns of speciation, followed by ecological studies, in both the
field and the laboratory. The research direction that took shape covered a large range of topics
concerning many aspects of this interesting group of earthworms.
Results of this research have been presented at various international symposia on earthworm
ecology. These results include (1) the first attempt to separate
Octodrilus
species by numerical
taxonomy (the Darwin Centenary Symposium on Earthworm Ecology, Grange-over-Sands, U.K.,
1981); (2) the theoretical background of
Octodrilus
species discrimination based on a hypothesis
of accelerated insularlike speciation (the Michaelsen Memorial Symposium on Terrestrial Earth-
worms, Hamburg, 1987); (3) the structure of earthworm communities and the role of large
Octodrilus
Octo-
drilus
species in building up certain so-called vermic characters in mountain soils (the Rosa
Symposium, Bologna, Italy, 1985; Fourth International Symposium on Earthworm Ecology (ISEE
4), Avignon, France, 1990; the 11th International Colloquium on Soil Zoology, Jyvskyl, Finland,
1992; and ISEE 5, Columbus, OH, 1994); and (4) molecular taxonomy research (the ISEE 7,
Cardiff, U.K., 2002).
This chapter provides a summary of the main results of all this research, whether previously
published or not. In addition, new laboratory research on the structure of deoxyribonucleic acid
(DNA) in
Octodrilus
species is presented.
