Allolobophora kosowensis kosowensis Karaman, 1968

Milutinović, Tanja, Milanović, Jovana & Stojanović, Mirjana, 2013, Threat status and distribution of the endemic species Allolobophora kosowensis kosowensis Karaman, 1968 (Oligochaeta: Lumbricidae) in the Balkans, Journal of Natural History 49 (5 - 8), pp. 471-481 : 473-480

Allolobophora kosowensis kosowensis Karaman, 1968

Karaman 1968, Zool Anz. 181: 50: Allolobophora kosowensis .

Zicsi 1982, Acta Zool Acad Sci Hung. 28 (3–4): 431: Allolobophora kosowensis .

Omodeo 1988, Boll Zool. 55: 81: Eophila kosowensis .

Mršić and Šapkarev 1988, Acta Mus Mac. Sci. nat. 19: 24: Allolobophora (Serbiona) kosowensis kosowensis .

Mršić 1991, Monog on earth of the Bal. 191: Serbiona kosowensis kosowensis .

Stojanović et al. 2007, Arch Biol Sci. 57: 129: Serbiona kosowensis kosowensis .

Stojanović et al. 2008, Eur J Soil Biol. 44: 60: Serbiona kosowensis kosowensis .

Description

External characters: The body is 134 mm long, consisting of 265 segments. The body colour is dark grey. The first dorsal pore is in intersegmental groove 11 / 12. The prostomium is one-half the epilobius. The male aperture with a small glandular atrium lies on the 15th segment. Glandular papillae surround setae ab on segments 17, 18 and 20. The clitellum extends from segments 33 to 49, 50, 51, 52 and the tubercula pubertatis are absent.

Internal characters: Four pairs of seminal vesicles in the 9th to 12th segments and two pairs of spermathecae in the 10th and 11th segments on the septa 9 / 10 and 10 / 11. The nephridial bladder is U-shaped.

New material examined

1 exp., Pančevo, 20 May 2007, (44 ◦ 52 ′ N, 20 ◦ 38 ′ E), 205 m above sea level .

The morphological variations of A. kosowensis kosowensis individuals found in Serbia are shown in Table 2. It is evident that there are no significant morphological differences among the individuals from various localities.

Biogeographical considerations

Based on all previously published data on the distribution of A. kosowensis kosowensis , it is clear that this subspecies is exclusively endemic for Serbia.

According to the data from Fauna Europaea ( Rota 2005), this subspecies inhabits Serbia and Montenegro but this subspecies has never been registered in Montenegro ( Stojanović et al. 2008).

Pančevo (the Vojvodina Province ) is a new finding and also the northernmost point of occurrence of this subspecies in the Balkans; Priština represents the southernmost limit of distribution of this subspecies . Pančevo is the first locality for A. kosowensis kosowensis in the Vojvodina Province , in northern Serbia. The easternmost point in its distribution is Radejna ( Figure 1 ), and it does not extend beyond Sjenica (Lisa Mt) in the west ( Table 1).

As a result of our survey, the new record of A. kosowensis kosowensis extends the known distribution range of the subspecies c. 300 km to the northeast – increasing the extent of occurrence for A. kosowensis kosowensis . Based on all the sites listed in Table 1, it was possible, for the first time, to display the area of extent of occurrence for A. kosowensis kosowensis graphically ( Figure 1 ). Unfortunately, this subspecies has not been found since 2007.

However , based on the analysis of the Institute’s collection, it was discovered that two individuals of A. kosowensis kosowensis were registered at two new locations in central Serbia (173 and 590 m above sea level) and three individuals in two localities in southern Serbia (near 500 m above sea level) ( Table 1) .

Given that A. kosowensis kosowensis lives deep in the soil, while on the surface it can be found in various biotopes, it is not possible to make any assumption about the distribution centre of this subspecies. Finding it depends on the amount of water used in the formaldehyde method as well as on precipitation around the time of sampling. This is supported by the fact that this subspecies was found in Priština ( Karaman 1968) in great numbers (at a depth of over 1.5 m) while digging the city’s water supply channels. However, based on the patterns of the present distribution of A. kosowensis kosowensis , we can safely conclude that the hilly mountainous area of Serbia has the most important role for its distribution.

The distribution map of this subspecies indicates that the high mountain ranges of the Dinarides in the west, the Carpatho-Balkan Mountains in the east, and the Macedonian mountains (which belong to the Rhodope massif) in the south are barriers that this subspecies cannot cross. The localities registered in the hilly regions that extend in the same direction as the Velika Morava river indicate the only possible migratory route of this subspecies towards the north (to Vojvodina), which is not interrupted by mountain ranges. The most recent registered locality in Vojvodina (Pančevo) provides proof of this assumption.

As a mainly hilly-mountain subspecies, it is only the individuals of A. kosowensis kosowensis from the Vojvodina Province (Pančevo) and the central part of Serbia (Kragujevac and Žitorad–a) that have been observed at an altitude of about 200 m, whereas in the other regions the subspecies can be found much higher. Most individuals have been found (in 80% of registered sites) at altitudes from 450 to 1030 m above sea level ( Table 2). These data, together with our results, indicate that the habitat of A. kosowensis kosowensis is mainly hilly mountains. These biogeographical considerations support Pop (1949), who hypothesized that earthworms were primarily of mountain origin, and from these places some species have migrated to closely located mountains as well as to the neighbouring hills and lowlands. However, most lowland species are usually widely distributed, although they have also been found at high altitudes. On the basis of these standpoints, Pop concluded that earthworms were obviously mountain animals.

Despite our intensive search, this subspecies has not been found in other regions of Serbia. Nevertheless, the fact that A. kosowensis kosowensis occurred in the Vojvodina Province, which represents the northernmost occurrence of this subspecies, is remarkable and could give us the right to expect further infiltration of a greater number of individuals to the north. Alternatively, the region of Vojvodina is under strong anthropogenic influence, so it is possible that the distribution of this subspecies will stop there.

Threat status and responsibility

Taking into account all previous biogeographical considerations, it is evident that there are a great number of limiting factors acting on the distribution of this subspecies. Consequently, it is necessary to apply the IUCN analysis and to evaluate the threat status of this rare subspecies. Data from all the investigations conducted so far are available, so it is possible to determine the threat status of A. kosowensis kosowensis on a global level. However, in applying the IUCN criteria on a global level, criterion B is the most important for invertebrates. Criterion B is based on the range size of a species (area of occupancy or extent of occurrence). Extent of occurrence is defined by the IUCN as “the area contained within the shortest continuous imaginary boundary that can be drawn to encompass all sites of present occurrence of a taxon”. Area of occupancy is defined as the area that is occupied by a taxon within its extent of occurrence.

Allolobophora kosowensis kosowensis is a rare subspecies known from altogether 18 locations on the Balkan Peninsula. The area of occupancy for A. kosowensis kosowensis is around 100 km 2.

The analysis based on the IUCN (2011) Red List Categories shows that A. kosowensis kosowensis has an Endangered status [B2b (ii, iii, iv, v) c (ii, iii, iv, iv)] on a global level.

Identifying A. kosowensis kosowensis as an endemic subspecies also indicates that it is the subspecies potentially in need of conservation or at least in need of monitoring for future negative changes. However, threat status does not always reflect actual conservation requirement ( Gärdenfors 2001) and it is necessary to determine the importance (i.e. responsibility) of a specific area for the global survival of a species. The concept of national or regional responsibility as a criterion for assessing conservation priorities is receiving increasing attention ( Schnittler et al. 1994; Keller and Bollmann 2004; Schmeller et al. 2008). Regional and national responsibility is a biogeographic criterion associated with distribution range. The responsibility concept was developed to underline the importance of a localized population for the global survival of a species. This criterion reflects whether the study area encloses a large part of the distribution of a species. Species may have a limited distribution and be endemic to a small area, where national responsibility for their conservation is high. Since A. kosowensis kosowensis is an endemic subspecies whose distribution is limited to one part of Serbia, it is clear that the state of Serbia has a very high responsibility for the global survival of A. kosowensis kosowensis .

Conclusions

Endemic species, particularly those of local and stenolocal distribution, greatly contribute to species diversity. The identification of target species for conservation is therefore a topic of particular interest.

Allolobophora kosowensis kosowensis , as a restricted endemic and endangered subspecies, is more exposed to threats and therefore its biological features should be the subject of preferential attention for conservationists. One of the aims of this study was to determine the conservation status of A. kosowensis kosowensis . Precise evaluation of its conservation status is a necessary condition to successfully prevent its extinction. We performed this study particularly because the countries of the Balkans do not have their own red lists for earthworms and none of the species has a legally protected status. Our knowledge of the distribution and abundance of A. kosowensis kosowensis is still imperfect. This means that threat status must be viewed as a working hypothesis based on the best available information. In addition, the analysis for assessing the vulnerability of species of a particular fauna is per se a never-ending dynamic process. Hence, this study provides a guide and stimulus for further study.

Figures

Figure 1. The distribution map of Allolobophora kosowensis kosowensis in the Balkans.