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Grazer‐induced colony formation in Scenedesmus : are there costs to being colonial?
Author(s) -
Lürling Miquel,
Van Donk Ellen
Publication year - 2000
Publication title -
oikos
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.672
H-Index - 179
eISSN - 1600-0706
pISSN - 0030-1299
DOI - 10.1034/j.1600-0706.2000.880113.x
Subject(s) - scenedesmus obliquus , photic zone , colonialism , biology , photosystem ii , settling , algae , scenedesmus , botany , photosynthesis , ecology , environmental science , phytoplankton , nutrient , environmental engineering , geography , archaeology
Grazer‐induced colony formation in the common green alga Scenedesmus acutus may be interpreted as an anti‐grazer defense. Costs are to be expected because otherwise the protected colonial morph would be the norm. Analysis of growth rates, light harvesting in terms of photosystem II (PSII) efficiency using Xe‐PAM fluorescence measurements and sedimentation rates were compared among unicellular and induced colonial populations. No differences in growth rates and PSII efficiency were detected between unicellular and colonial populations. However, colonial populations had higher settling velocities than unicellular populations. Hence, costs may be attributed to enhanced sinking out of the euphotic zone resulting in reduced growth due to lower light and temperature in deeper water layers.