pH-taxis by the dispersal stage of choanoflagellates.

We used video microscopy to study the response to gradients of pH of choanoflagellate Salpingoeca rosetta. This choanoflagellates presents a life history that includes fast- and slow-swimming unicellular forms and multicellular colonies. In the associated data we show and quantify the presence of both types of unicellular swimmers.The data shows that unicellular fast swimmers exhibited taxis into patches of attractant. When this type of choanoflagellates is exposed to patches with different pH, we observed accumulation of cells in regions where pH is in the range of 6 to 7. In contrast, a repulsive response is observed at lower pH.