Scenedesmus is is a cosmopolitan green freshwater algae.
Because of the colonial symmetry of Scenedesmus, its size/shape
differences and abundant cytological features (both LM and EM), it first
seemed that individuals could easily be distinguished and classified. Because
biologists often examined samples of Scenedesmus taxa at only one point
in time, they tacitly assumed that there was stability of form.
Are there data confirming stability of form?
On the other hand, preserved collections are not useful
material to support an alternate hypothesis.
The result: hundreds of species and innumerable subspecific taxa were
identified and described.
In Scenedesmus Phenotypic Plasticity the author presents
- Early reports of variability or polymorphism, along with their
routine dismissal as supposedly irrelevant observations.
- Chapters concerned with geographical distribution, culture
techniques, history and the Scenedesmus unicell, indicating the
need for the renaissance of the phenotype.
The concept of an ordered developmental sequence is developed and discussed.
Data from numerous laboratories, whether cytological,
morphological, biochemical, ecological or physiological, which
lend support to the concept of plasticity in all strains. Numerous
supposed taxa are but ecomorphs of rather complex taxa.
History: Collecting and Cataloging 9
Geographical Distribution of Scenedesmus Species 27
Cytology and Reproduction 49
Culturing Algae: Impact on Scenedesmus Development 85
Unicells: A Scenedesmus Ecomorph 109
Scenedesmus Phenotypic Plasticity: Scope and Consequences 146
A Broadly Defined Species: Scenedesmus armatus 188
Phenotypic Plasticity in Multi-spined Species: Response to Nutrients & Temperature 215
Selection of Stable Characters: Morphology Yesterday, Today, Tomorrow 256
Phenotypic Plasticity: Past, Present and Future 275
Scenedesmus Identification Recognizing Phenotypic Plasticity 302
References - Index 339