Effects of water temperature and pH value on covering behavior of the sea urchin Glyptocidaris crenularis

Abstract

As marine calcifying organisms, sea urchins are sensitive in the changing ocean. More information is needed about the effects of pH value and water temperature on behaviors of sea urchins. Here, we reported that pH value and water temperature significantly affected the covering behavior of sea urchins Glyptocidaris crenularis. Lower pH value (pH = 7.4) significantly reduced the time to first covering (p = 0.026), while significantly decreased number of covered sea urchins (p = 0.029) and number of shells used for covering (p = 0.007) in G. crenularis. Water temperature did not significantly affect the time to first covering (p = 0.180) or number of covered sea urchins (p = 0.157), though significantly affected number of shells used for covering (p = 0.042). The present study provides preliminary information on behavioral ecology of sea urchins. Notably, the effects of CO2 induced acidification should be further investigated in future.