Dear Jean-François

According to Eggers T. O. / Eiseler B. 2007: Bestimmungsschlüssel der Süsswasser-Spongillidae Mittel- und Nordeuropas, Lauterbornia 60: 1–53 (http://shop.lauterbornia.de/product_info.php?products_id=180).

It seems to be E. muelleri. Diagnostics length and width of amphidiscs are approximately equal (longer than wide in E. fluviatilis). Macrosclera can also have spines (these lacking in E. fluviatilis).

Les echantillons sont de quelle station?

Best wishes, meilleurs salutations

Daniel

Thank you for your answer. I found the sample in the river Seine Near Nogent-sur-Seine. 48°29'45.04"N 3°28'6.32"E

I have other pictures from the same sponge.

Best wishes

Dear Jean François

according to the nuew photos I think Ehydatia muelleri ist correct.

Compare with the key attached form the «Stresemann» most actaul edition of 2019 (but unhappily in german).

Best wishes

Daniel

Thank you very much. The PDF is great.

I found also Trochospongilla horrida near the River Seine in a smal river. 48°28'7.69"N 3°25'31.92"E.

Best Wishes