Abundance and microhabitats of freshwater sponges (Spongillidae) in a Danubean floodplain in Austria
Abundance and microhabitats of freshwater sponges (Spongillidae) in a Danubean floodplain in Austria
复制标题
奥地利多瑙河洪泛区淡水海绵（海绵科）的丰度和微生境
DOI：
10.1111/j.1365-2427.2007.01747.x
复制
发表时间：
2007
影响因子：
2.7
通讯作者：
J. Waringer
中科院分区：
文献类型：
--
作者：
Iris Dröscher;J. Waringer
总结
Summary
1. This study examined the abundance and distribution of freshwater sponges (Spongillidae) at 32 sites in a floodplain on the Danube within the ‘Donau-Auen’ National Park east of Vienna, Austria. Ranked from abundant to rare, the species inventory comprised Ephydatia fluviatilis, Spongilla lacustris, Ephydatia mulleri, Eunapius fragilis and Trochospongilla horrida.
2. The presence of hard substratum was essential for the growth of sponges. Timber stands near the water and drifting dead wood increased the abundance of E. fragilis, E. fluviatilis and E. mulleri, whereas stony substrata were important for S. lacustris. A small fraction of E. fluviatilis was collected from macrophytes (Phragmites).
3. Based on the area colonised, the abundance of S. lacustris, E. fragilis and E. fluviatilis was highest (94.2–100% of the total) in floodplain waters where hydrological connectivity with the Danube was low (0–6 days year−1), whereas E. mulleri and T. horrida made up 20.3–35.9% of the total at sites connected for up to 179 days year−1. Moreover, the area colonised by T. horrida at a current velocity >0.20 m s−1 was larger than in the remaining species. Sites with E. mulleri and T. horrida had a higher silicon concentration (0.9 mg L−1) than sites where the remaining three species were collected (0.4–0.6 mg L−1).
4. In most species, the length of macroscleres (the larger spicules) was positively correlated with conductivity and negatively with pH. With respect to aberrant macroscleres, hooks were observed most frequently, whereas the proportion of centrotylotes (ie with the one on more globular swellings along the spicule) was lowest.
5. Freshwater sponges have a great deal of potential as bioindicators and restoration measures that improve floodplain connectivity will favour rare species, such as E. mulleri and T. horrida, while impairing others (e.g. E. fragilis, S. lacustris and E. fluviatilis).