The mean righting times of the sea urchins (A- long spined urchin and B- rock boring urchin) when compared to increasing temperatures.

Within this study, it was found that both species of sea urchin acclimatized to the changing temperature over time.  However, even though they both acclimatized, they did have different thermal tolerance levels.  The long spined urchins had the biggest range of thermal tolerance during the winter, and a much smaller range for the summer; the rock boring urchin, however, had the opposite.  The rock boring urchin had a large range of thermal tolerance during the summer, and a much smaller range during the winter.  This difference in thermal tolerance may be due to where these urchins can be found during the day.  The long spined urchins are often found out in the open during the day, while the rock boring urchins spend most of the day crammed between rocks and coral.  Since the rock boring urchins are hidden they are protected from the ever changing environment surrounding them.  Since the urchins are protected  they are less likely to be affected by the drastically changing temperature, and thus have less of a need for a higher thermal tolerance.
     
As can be seen from the figure above, the urchins also had very different righting times when the temperature was below the thermal tolerance.  There is one main theory for the different righting times (other than the idea of urchins having different thermal tolerances). It could be due to the fact that the long spined urchins have longer spines, which they used to flip themselves over.  Whereas the rock boring urchins don't have these long spines, so have to use other means such as their tube feet, to flip themselves over, which is much more time consuming.

Further studies need to be conducted to further understand how the changing temperatures of the water will affect the urchins.  The studies need to focus on both the long term and the short term effects of the changing environment.  Further studies also need to be conducted to figure out how fast the temperature can change before the sea urchins are unable to acclimatize.  This will give us an idea of how rapid the temperature change needs to be before the sea urchins are killed off, thus severely affecting the coral reefs ecosystem.    

Information Credit: Sherman E.  2015.  Can sea urchins beat the heat? Sea urchins, thermal tolerance, and climate change.  [Cited November 16, 2015].  PeerJ 3:e1006  Available from: http://dx.doi.org/10.7717/peerj.1006

Photo Credit: Sherman E.  2015.  Can sea urchins beat the heat? Sea urchins, thermal tolerance and climate change.  [Cited November 15, 2015].  PeerJ 3:e1006  Available from: http://dx.doi.org/10.7717/peerj.1006