Polymorphism in soft coral larvae revealed by amplified fragment-length polymorphism (AFLP) markers

The dioecious Red Sea soft coral Parerythropodium fulvum fulvum breeds its nonsymbiotic planula larvae on the surface of female colonies for less than a week. After completing their development, larvae crawl and settle near m aternal colonies. Here we study the genetic polymorphism of developing larv ae by the use of amplified fragment-length polymorphism markers. Four repro ductive colonies from shallow water populations (two from a dense populatio n and two from a less densely populated area 100 m away) were chosen, and t en larvae were randomly collected from each colony. DNA was analyzed by usi ng three different primer combinations producing 61, 63, 63 polymorphic mar kers, respectively. All larvae exhibited different banding patterns from on e another, illustrating the prominent role of sexual reproduction for the p roduction of larvae. Nei's mean genetic distances for all 12 possible pair- wise combinations for larval origins revealed, in most cases, that sister l arvae are genetically closer than larvae from different colonies and that l arvae may be grouped into three statistical clusters in accordance with col ony origin and population studied. The usefulness of molecular methodologie s in coral population genetics is discussed.