The relevance of desmids in the biological typology and evaluation of fresh waters P. F. M. Coesel OriginalPaper Pages: 93 - 101
The use of microsystems for the evaluation of the effect of toxicants Kees Kersting OriginalPaper Pages: 102 - 108
Orconectes limosus (Raf.) andAstacus astacus L. (Crustacea, Decapoda) in The Netherlands J. F. M. Geelen OriginalPaper Pages: 109 - 113
Immigrants among the animals of the Delta-area of the SW. Netherlands K. F. Vaas OriginalPaper Pages: 114 - 119
Geographical distribution and biology ofDreissena polymorpha Pallas P. Leentvaar OriginalPaper Pages: 120 - 122
The immigrant triclad flatwormDugesia tigrina (Girard) (Plathelminthes, Turbellaria). Range-extension and ecological position in The Netherlands G. Van Der Velde OriginalPaper Pages: 123 - 130
The introduction of the alien amphipodGammarus tigrinus Sexton, 1939 (Crustacea, Amphipoda) in The Netherlands and its competition with indigenous species Sjouk Pinkster OriginalPaper Pages: 131 - 138
