Abstract
The area of Donji Kamenjak (Istria, Croatia) is locus typicus for the species Octodrilus istrianus Mršić, 1991. However, the whole earthworm fauna has not been investigated. Given that O. istrianus is an endemic species to the Istrian region, this fact inspired our research in this small, but unique location. Field samplings were conducted over a two-year period (2020–2021), with biannual collections in both spring and autumn. In total, we identified nine earthworm species, including eight from the Lumbricidae family and one from the Acanthodrilidae family. We confirmed the presence of O. istrianus Mršić, 1991 and, for the first time in Croatia, documented the presence of Microscolex dubius (Fletscher, 1887). The most abundant species was Octodrilus kvarnerus Mršić, 1987, also an endemic species for this area. The endemic species O. istrianus in this surveyed area faces threats from habitat degradation, mechanical land cultivation practices, wild boars foraging and the impact of tourism during the majority of the year.
References
- Baubet, E., Ropert-Coudert, Y. & Brandt, S. (2003) Seasonal and annual variations in earthworm consumption by wild boar (Sus scrofa scrofa L.). Wildlife research, 30, 179–186. https://doi.org/10.1071/WR00113
- Bogdanović, S., Iveša, N., Temunović, M. & Ljubičić, I. (2018) Plant Diversity of Gornji Kamenjak (Istria, Croatia). Agriculturae Conspectus Scientificus, 83 (3), 195–204.
- Boyer, S., Kim, Y.N., Bowie, M.H., Lefort, M.C. & Dickinson, N.M. (2016) Response of endemic and exotic earthworm communities to ecological restoration. Restoration Ecology, 24 (6), 717–721. https://doi.org/10.1111/rec.12416
- Briones, M.J.I. & Schmidt, O. (2017) Conventional tillage decreases the abundance and biomass of earthworms and alters their community structure in a global meta‐analysis. Global change biology, 23 (10), 4396–4419. https://doi.org/10.1111/gcb.13744
- Buckley, T. R., Boyer, S., Bartlam, S., Hitchmough, R., Rolf, J. & Stringer, I. (2015) New Zealand Conservation status of New Zealand Earthworms, 2014. New Zealand Department of Conservation.
- Csuzdi, Cs., Pop, V.V. & Pop, A.A. (2011) The earthworm fauna of the Carpathian Basin with new records and description of three new species (Oligochaeta: Lumbricidae). Zoologischer Anzeiger, 250, 2–18. https://doi.org/10.1016/j.jcz.2010.10.001
- Csuzdi, Cs., Szederjesi, T., Marchán, D.F., Sosa, I.D., Gavinelli, F., Dorigo, L., Pamio, A., Dreon, A.L., Fusaro, S., Moretto, E. & Paoletti, M.G. (2018) DNA barcoding of the Italian anecic Octodrilus species in rural (vineyard) and forested areas with description of Octodrilus zicsiniello sp. nov.(Clitellata, Megadrili). Zootaxa, 4496 (1), 43–64. https://doi.org/10.11646/zootaxa.4496.1.5
- Farfan, M.A., Guerra, C.A., Hedlund, K., Ingimarsdóttir, M., Barrios, E., Cox, N., Dahlberg, A., Delgado-Baquerizo, M., Eisenhauer, N., Lundesjö, M. & Orgiazzi, A. (2024) Preliminary assessment of the knowledge gaps to improve nature conservation of soil biodiversity. Soils for Europe, 1, e118853. https://doi.org/10.3897/soils4europe.e118853
- Granval, P. & Muys, B. (1995) Predation on earthworms by terrestrial vertebrates. In: Golovatch, S. & Penev, L. (Eds.), Proceedings of the International Union of Game Biologists XXII Congress. Pensoft, Sofia, Bulgaria, pp. 480–491.
- Guerra, C.A., Bardgett, R.D., Caon, L., Crowther, T.W., Delgado-Baquerizo, M., Montanarella, L., Navarro, L.M., Orgiazzi, A., Singh, B.K., Tedersoo, L. & Vargas-Rojas, R. (2021) Tracking, targeting, and conserving soil biodiversity. Science, 371 (6526), 239–241. https://doi.org/10.1126/science.abd7926
- Hackenberger Kutuzović, D. & Hackenberger Kutuzović, B. (2013) Checklist of the earthworm fauna of Croatia (Oligochaeta: Lumbricidae). Zootaxa, 3710 (1), 1–30. https://doi.org/10.11646/zootaxa.3710.1.1
- Hackenberger Kutuzović, D., Hackenberger Kutuzović, D., Đerđ, T. & Hackenberger Kutuzović, B. (2019) ErIK—a software-based identification key for earthworm species of Croatia. Zootaxa, 4613 (3), 594–595. https://doi.org/10.11646/zootaxa.4613.3.11
- Hackenberger, D.K. & Hackenberger B.K. (2014) Earthworm community structure in grassland habitats differentiated by climate type during two consecutive seasons. European Journal of Soil Biology, 61, 27–34. https://doi.org/10.1016/j.ejsobi.2014.01.001
- Horvat, I. (1949) Nauka o biljnim zajednicama. Nakladni zavod Hrvatske, Zagreb
- Koren, T. (2022) The Diversity of Moths (Lepidoptera: Heterocera) of Significant Landscape Donji Kamenjak and Medulin Archipelago, Istria, Croatia. Annales: Series Historia Naturalis, 32 (1), 237–260.
- Lehmitz, R., Römbke, J., Graefe, U., Beylich, A. & Krück, S. (2016) Rote Liste und Gesamtartenliste der Regenwürmer (Lumbricidae et Criodrilidae) Deutschlands. In: Gruttke, H., Binot-Hafke, M., Balzer, S., Haupt, H., Hofbauer, N., Ludwig, G., Matzke-Hajek, G. & Ries, M. (Eds.), Rote Liste gefährdeter Tiere, Pflanzen und Pilze Deutschlands, Band 4 (Wirbellose Tiere), Teil 2. Landwirtschaftsverlag, Münster. Naturschutz und Biologische Vielfalt, 70 (4), 565–590.
- Ljubičić, I., Britvec, M., Jelaska, S.D. & Husnjak, S. (2014) Plant diversity and chemical soil composition of rocky pastures in relation to the sheep grazing intensity on the northern Adriatic islands (Croatia). Acta botanica Croatica, 73 (2), 419–435. https://doi.org/10.2478/botcro-2014-0003
- Ljubičić, I., Paulik, H. & Bogdanović, S. (2020) Habitat mapping of protected landscape of Donji Kamenjak, Istria (Croatia). Journal of Central European Agriculture, 21 (3), 676–685. https://doi.org/10.5513/JCEA01/21.3.2697
- Marchán, D.F. & Domínguez, J. (2022) Evaluating the Conservation Status of a North-Western Iberian Earthworm (Compostelandrilus cyaneus) with Insight into Its Genetic Diversity and Ecological Preferences. Genes, 13 (2), 337. https://doi.org/10.3390/genes13020337
- Monroy, F., Aira, M., Gago, J.Á. & Domínguez, J. (2007) Life cycle of the earthworm Octodrilus complanatus (Oligochaeta, Lumbricidae). Comptes Rendus Biologies, 330 (5), 389–391. https://doi.org/10.1016/j.crvi.2007.03.016
- Mršić, N, (1987) Description of the five new species of the genus Octodrilus Omodeo 1956 (Oligochaeta: Lumbricidae). Biosistematika, 13 (1), 37–44.
- Mršić, N. (1991) Monograph on earthworms (Lumbricidae) of the Balkans (Part I & II). Slovenska akademija znanosti in umetnosti, Ljubljana.
- Pop, A.A., Pop, V.V. & Csuzdi, Cs. (2010) Significance of the Apuseni Mountains (the Carpathians) in the origin and distribution of Central European earthworm fauna. Zoology in the middle east, 51 (sup2), 89–110. https://doi.org/10.1080/09397140.2010.10638462
- QGIS Development Team (2024) QGIS Geographic Information System 3.28.3
- Rutgers, M., Orgiazzi, A., Gardi, C., Römbke, J., Jänsch, S., Keith, A.M., Neilson, R., Boag, B., Schmidt, O., Murchie, A.K. & Blackshaw, R.P. (2016) Mapping earthworm communities in Europe. Applied Soil Ecology, 97, 98–111. https://doi.org/10.1016/j.apsoil.2015.08.015
- Škorić, A. & Bogunović, M. (1987) Geografija tala. In: Škorić, A. (Ed.), Pedosfera Istre (sa pedološkom kartom). Projektni savjet pedološke karte Hrvatske, Posebna izdanja, knjiga 2, Zagreb.
- Stojanović, M. & Karaman, S. (2006) Threat status and distribution of the earthworm genus Helodrilus Hoffmeister, 1845; sensu Zicsi 1985, on the Balkans and the neighboring regions. Biodiversity & Conservation, 15 (14), 4601–4617.
- Stojanović, M., Milutinović, T. & Karaman, S. (2008) Earthworm (Lumbricidae) diversity in the Central Balkans: An evaluation of their conservation status. European Journal of Soil Biology 44 (1), 57–64. https://doi.org/10.1016/j.ejsobi.2007.09.005
- Stojanović, M., Sekulić, J. & Trakić, T. (2017) Distribution and threat status of the endemic earthworm Allolobophora dofleini (Oligochaeta, Lumbricida) on the Balkan Peninsula. North-Western Journal of Zoology, 13 (1), 136–143.
- Topić, J. & Šegulja, N. (2000) Floristic and ecological characteristics of the southernmost part of Istria (Croatia). Acta Botanica Croatica, 59 (1), 179–200.
- Trakić, T., Valchovski, H. & Stojanović, M. (2016) Endemic earthworms (Oligochaeta: Lumbricidae) of the Balkan Peninsula: a review. Zootaxa, 4189 (2), 251–274. https://doi.org/10.11646/zootaxa.4189.2.3
- Vidaček, Ž. (1979) Osnovna pedološka karta sekcije Pula 1, mjerila 1:50000. Projektni savjet za izradu pedološke karte SR Hrvatske, Zagreb
- Vuković, N. (2010) Rt Kamenjak. In: Nikolić, T., Topić, J. & Vuković, N. (Eds.), Important plant areas of Croatia. Školska knjiga Zagreb, Hrvatska, pp. 374–378.
- Winding, A., Singh, B.K., Bach, E., Brown, G., Zhang, J., Cooper, M., Dion, P., Mele, P., Eisenhauer, N., Pena-Neira, S. & Lindo, Z. (2020) State of knowledge of soil biodiversity: status, challenges, and potentialities. Food and Agriculture Organization of the United Nations. https://doi.org/10.4060/cb1928en
- Zeiss, R., Eisenhauer, N., Orgiazzi, A., Rillig, M., Buscot, F., Jones, A., Lehmann, A., Reitz, T., Smith, L. & Guerra, C.A. (2022) Challenges of and opportunities for protecting European soil biodiversity. Conservation Biology, 36 (5), 13930. https://doi.org/10.1111/cobi.13930