Notes and new data on the distribution of a non-native oligochaete: Branchiura sowerbyi (Beddard, 1892) in Croatia

Abstract

The freshwater oligochaete Branchiura sowerbyi is indigenous to southeast Asia, but can be found inhabiting most of Europe. This tubificid was even described for the first time outside of its natural area of occurrence: in the garden of the Royal Botanic Society in London. It has spread over all continents except Antarctica, and in Europe it has been found in 23 countries. The presence of this non-native species may affect other species' relationships in the benthic community and thus have substantial effects on food webs of aquatic ecosystems. Our goal was to present the first comprehensive overview of the distribution of this potentially invasive species in Croatia as a basis for the future monitoring of the species distribution. In Croatia, B. sowerbyi was found for the first time in 1954 in Varaždin's thermal stream and the following year in the lake of the Botanical garden, Faculty of Science, University of Zagreb. To date, B. sowerbyi individuals were found on 64 different sites in Croatia, mostly occupying the Pannonian Lowland Ecoregion (ER 11) with only two findings in the Dinaric Western Balkan Ecoregion (ER 5). Vučković, N., Pozojević, I., Kerovec, M., Dorić, V. & Mihaljević, Z.: Pregled istraživanja i novi nalazi rasprostranjenosti alohtonog maločetinaša Branchiura sowerbyi u Hrvatskoj. Nat. Croat., Vol. 28, No. 2., 455-462, Zagreb, 2019. Prirodni areal rasprostiranja vrste Branchiura sowerbyi je jugoistočna Azija, no ovaj se maločetinaš može pronaći u slatkovodnim ekosustavima diljem Europe. Čak je i prvi opis ove vrste tubificida bio izvan njegovog prirodnog areala rasprostiranja, točnije u botaničkom vrtu "Royal Botanic Society" u Londonu. Ova vrsta danas je prisutna na svim kontinentima osim Antartike, a u Europi je zabilježena u 23 zemlje. Prisustvo ove alohtone vrste može imati još neutvrđene implikacije na zajednice slatkovodnih makroskopskih beskralježnjaka, kao i na funkcioniranje hranidbenih mreža unutar ovih zajednica. Cilj ovog rada bio je izraditi sveobuhvatan pregled distribucije ove vrste na području Hrvatske kao bazu za buduće nadziranje širenja te vrste. U Hrvatskoj je vrsta B. sowerbyi nađena prvi put 1954. godine u termalnom potoku u Varaždinu, a već sljedeće godine pronađena je u Botaničkom vrtu Sveučilišta u Zagrebu. Dosad je vrsta zabilježena na 64 različite lokacije na području Hrvatske, većinom u Panonskoj ekoregiji (ER 11), dok je u Dinaridskoj ekoregiji (ER 5) dosad zabilježena na samo dvije lokacije.

Macroinvertebrate Community Responses to Multiple Pressures in a Peri-Urban Mediterranean River

“…The non-native species B. sowerbyi, a thermophilous tropical species tolerant to several toxins, is favored when the substrate has important quantities of sludge from effluents [65], which is exactly the case of Laspias. Moreover, this species is characterized by high distributional spreading and breeding rates, which could cause various instabilities in freshwater ecosystems, such as habitat degradation [66]. Therefore, communities were characterized by low local taxa richness and exhibited similar composition both in space and time.…”