EARTHWORMS ( ANNELIDA : OLIGOCHAETA ) OF KRAGUJEVAC BASIN-A REVIEW

In this paper, we have summarized the current knowl edge on earthworm diversity in the central part Serbia, Kragujevac ba sin. The complete list of earthworm taxa comprises 37 species and subspecies, belonging to 1 3 genera of the family Lumbricidae. Among them, Dendrobaena serbica (Šapkarev, 1977) is registered for the first time i n the study area. With respect to the zoogeographic situa tion, most of the earthworm species belong to Peregrine, Endemic, and Central European chorological groups. The endemic species take part of 21.05% in the total number of the species. The most of endemic species belong to the genus Allolobophora. Summing up the endemics and the Balkanic species, 31.58% of the total lumbricid fauna shows an autochthonous character.


INTRODUCTION
One of the European hotspots of biodiversity is the Balkan Peninsula (GRIFFITHS et al. 2004).Faunistic research of Serbia, as part of the Balkan Peninsula contributed significantly to understanding the extremely diverse and complex soil fauna of the Balkan Peninsula.
Therefore, the aim of this paper is to summarize the published data on the earthworm fauna of the Kragujevac basin in order to establish the definitive list of known earthworm taxa.The list underlines earthworm diversity and provides a general overview of their distribution and zoogeographical position.

MATERIAL AND METHODS
Our investigations were carried out in the area of Kragujevac basin in the Central part of Serbia (Figure 1).Kragujevac basin is surrounded by Šumadija mountains Rudnik, Crni Vrh and Gledić Mountains.These mountains are rich in forests, river flows, pastures and mineral resources.The lowland part of the Kragujevac basin makes valley plains Lepenicа and its tributaries, the left Drača and Petrovac River, and on the right Grošnicа and Ždraljica River.The climate is moderate continental.Self-sown vegetation makes the environment of Kragujevac: woodland, meadow and wetland vegetation.Forests occupy 23% of the total area.On all over the territory of Kragujevac basin earthworms were collected from various habitats which included natural (river banks, meadows, forest community: Quercetumconfertae cerris and Fagetum montanum; mountain pasteurs) and cultivated biotopes.
Earthworms were collected using the diluted formaldehyde method complemented with digging (0.4x0.4 m 2 ) and hand sorting as well as turning over rocks, debris and logs.The earthworms were killed in 70% ethanol, immediately fixed in 4% formalin solution and transferred and stored in 90% ethanol.
Data on species were obtained from the fieldwork and from our old collections.Species identification was made according to the complex features provided in ŠAPKAREV (1978), ZICSI (1982), MRŠIĆ (1991), CSUZDI and ZICSI (2003) and BLAKEMORE (2004).
We collected all available literature data on earthworms in order to establish the definitive list of biogeographic type.It was used categorization of lumbricid species on the basis of their geographical distribution proposed by CSUZDI and ZICSI ( 2003

RESULTS
Starting from the total number of earthworms listed by BLESIĆ et al. (1998) and taking into account recent researches (mentioned above), as well as the fact that one species was found to be synonymous (Aporrectodea rosea bimastoides (Cognetti, 1901), the total number of earthworm species in the basin of Kragujevac comprises 38 taxa belonging to 13 genera (Tab.1).
Allolobophora kosowensis is exclusively endemic to Serbia.Considering that A. kosowensis species that lives deep in the soil, can be found in different biotopes.On the basis of data on the distribution of this species, it can be safely concluded that the mountainous region of Serbia has a crucial role in its distribution, so that the valley of the river Velika Morava indicates the only possible migratory route of this species to the north to the northernmost point of its spread (Pančevo, Pannonian basin) (MILUTINOVIĆ et al., 2015b).It was first described from the southern part of Serbia (KARAMAN, 1968).Later on, it has been registered in several localities in the southern, southeastern, central and southwestern parts of Serbia (ŠAPKAREV, 1988;KARAMAN and STOJANOVIĆ, 1996;STOJANOVIĆ, 1996;STOJANOVIĆ andKARAMAN, 2005, 2007;STOJANOVIĆ et al., 2008).
Allolobophora spasenijakaramani belongs to an archaic group whose center of development must have been situated on the Serbo-Macedonian tectonic plates that is a belt stretching in north-south direction along the Great and South Morava valleys, into western Republic of Macedonia and northern Greece (MRŠIĆ, 1991).It was first described from the central part of Serbia (KARAMAN, 1983;MRŠIĆ, 1991).Since then, it has been discovered in several localities in central, southeastern (KARAMAN, 1987 Besides the endemic species, the earthworm fauna of Kragujevac basin consists of species that are classified into six zoogeographic categories.One of the most common zoogeographical types of central Serbia is the widespread Peregrine group consists of species of the genera Allolobophora, Aporrectodea, Dendrobaena, Dendrodrilus, Eisenia, Eiseniella, Lumbricus and Octolasion. Widely distributed Trans-Aegean species group (Allolobophora leoni, Aporrectodea handlirschi, Ap. jassyensis and Octodrilus transpadanus) shows a range of distribution extending from Italy to Turkey (MISIRLIOĞLU, 2008;CSUZDI et al., 2011).
Aporrectodea smaragdina, Fitzingeria platyura platyura, Lumbricus polyphemus, Proctodrilus antipai and Eisenia lucens show a typical Central-European distribution.E. lucens occurring in Central Europe from the Alps to the Balkans, but it can be found also outside of this area, in the Pyrenean mountains.It could be said that it is an expanded Central European type of distribution.
In the Kragujevac basin, we registered only two species, Dendrobaena byblica and Octodrilus complanatus having typical Circum-Mediterranean type of distribution (CSUZDI and PAVLIČEK, 2005), as well as Aporrectodea georgii with Atlantic-Mediterranean type of distribution.
The diversity of fauna of Kragujevac basin is conditioned by variety of factors such as moderate continental and Mediterranean climate, variety of geological substrates, and the presence of different types of soils.The relief is dominated by vast networks of river valleys, between which rises isolated the island's mountains, up to 1200 m.Besides that, this аrea, as a part of the Balkan Peninsula, was refuge for many species of Europe, during the last ice age.All these factors have caused the heterogeneity of biotopes and, consequently, great biodiversity earthworms in this area.

Table 1 .
List of the earthworms taxa with distribution type.