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Resting spore formation of Leptocylindrus danicus (Bacillariophyceae) during short time‐scale upwelling and its significance as predicted by a simple model

1987; Springer Science+Business Media; Volume: 2; Issue: 3 Linguagem: Inglês

10.1007/bf02349776

1440-1703

Joji Ishizaka, Motonori Kaichi, Masayuki Takahashi,

Diatoms and Algae Research

Abstract Resting spore formation during short time‐scale upwelling and its significance were investigated in the field and by a simple theoretical model. Field observations of spore formation of Leptocylindrus danicus were made off Izu Peninsula, Japan. A rapid increase in ratio of resting spore to vegetative cell numbers indicated that L. danicus formed resting spores quickly as a response to nutrient depletion in the upwelled water, although only a very low number of resting spores was found in the upwelling. A simple model was constructed to investigate the possible advantages of spore formation during short time‐scale upwelling. This showed that there is a critical time‐scale for resting spore formation to be advantageous. The nutrient depletion period of the upwelling off Izu was shorter than the critical time‐scale determined by the model. Rapid‐sinking of resting spores may increase further the critical time‐scale, unless spores return with upwelling water. For short time‐scale upwelling, the vegetative cell may be better suited than the resting spore for enduring a short period of nutrient depletion.