Sexual Reproduction of Mediterranean Scleractinian Corals

Abstract

The reproduction of scleractinian corals is a fundamental process for maintaining their populations and is essential for understanding the corals’ ecology. However, it has been described in less than 30 % of known species. The majority of these studies were carried out in the tropics. In the Mediterranean, data are limited to historical observation by Lacaze-Duthier and more recent in-deep research on reproductive biology of Balanophyllia europaea, Leptopsammia pruvoti, Cladocora caespitosa, Astroides calycularis, Caryophyllia inornata and the invasive species Oculina patagonica. The Mediterranean Sea is characterized by marked seasonal patterns of seawater temperature that is driven by photoperiod and solar radiation, distinctive of temperate latitudes. Temperature and photoperiod are some of the environmental factors that influence organisms at all structural levels by controlling their physiological and reproductive processes. Climate change is leading to variations of environmental factors such as temperature, which could affect the population biology of corals by reducing their reproductive efficiency, as confirmed by several studies. This chapter focuses on analyzing the studies on sexual reproduction of Mediterranean scleractinians, integrating current understanding of the potential impacts of environmental changes on corals’ reproductive output. Investigating how reproductive processes are affected by changing environmental conditions under different future scenarios of stress levels (in mesocosm or in field experiments), could help to identify important processes that may have been overlooked in the past.