The latest AquaPlanta (2001/4) contains a review on Christel Kasselmann's latest book on the Echinodurus genus. If the review (by Josef Bogner)is an indication, then this book is going to clear up a lot the questions surrounding E.tennellus. Unfortunately, as always with Kasselmann's books, it will be in published in German. There's no reference to other language releases. Michael Eckardt