Meeting Abstract
Increasing surface sea temperatures are having an increasing impact on marine environments. Sea urchins are ideal model organisms to focus on, as they are excellent indicator species in regards to their response to global climate changes. They are also an ancient and relatively simple species, meaning that there are fewer internal mechanisms to deal with when observing responses. In this study, we tested the effect of higher temperatures on reproductive functions, heat shock protein expression, and ceolomic fluid (CF, a body fluid which regulates important physiological processes) conditions in Atlantic sea urchin at three different temperatures. Ten sea urchins were placed in each of six aquariums (capacity: 20-gallon) with high temperatures (28 and 32oC) and control variable (24oC) under controlled laboratory conditions for a 7-day period. For this experiment, the reproductive functions and heat shock protein expression focused on both male and female specimens. Sea urchin exposed to high temperature had the lower gonadal growth (gonad weight/body weight*100) compared to controls. The percentage of mature eggs (ova) was also significantly lower at high temperature compared to controls, indicating impaired ovarian functions at high temperatures. Sperm production also displayed a tendency to decrease from the lower to higher temperatures. Sea urchin exposed to high temperature showed an increased heat shock protein expression in eggs, follicles, and sperm, as well as increased cellular apoptosis and decreased CF pH compared to controls. These results suggest that elevated water temperature decline/acidify CF pH which might be involved in the impairment of reproductive functions and cellular apoptosis in Atlantic sea urchin.
