Physiological response of the cold-water coral Desmophyllum dianthus to different salinity and temperature regimes

This study investigates the effect of hypersalinity, both alone and in combination with elevated temperature, on the cosmopolitan cold-water coral Desmophyllum dianthus from the Chilean Fjord region to assess its acclimatization potential to Mediterranean conditions, where the species can also be found. Specimens were collected in Comau Fjord (Chile) and maintained in aquaria at the Alfred Wegener Institute (Germany) in three different treatments for three months: 1) Control with Chilean temperature (11°C) and salinity (31), (2) Chilean salinity with Mediterranean temperature (12°C), and (3) Mediterranean temperature and salinity (12°C and 38, respectively). The growth rate of the corals was investigated at the end of the 35-day acclimatisation pertiod and after 50 days under experimental conditions. The short- and long-term respiration rate of the corals was measured after 3 and 50 days of exposure. Polyp extension rates were determined 5 times per week both in the morning and in the evening.