Theory 72/Freshwater & Wetland/Riverine fish
Fish Follow Flow and Structure
The claim
Riverine fish assemblage diversity is set by the ratio of flow variability to habitat complexity, so a variable river with simple habitat supports fewer species than a stable one with complex habitat.
01Mechanism
Species specialise on flow conditions or on structure; the ratio determines how many niches exist.
02Prediction
Diversity should track the ratio.
03Refutation
Diversity tracking flow alone would remove habitat.