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 maternal colonies. Here we study the genetic polymorphism of developing larvae by the use of amplified fragment-length polymorphism markers. Four reproductive colonies from shallow water populations (two from a dense population and two from a less densely populated area 100 m away) were chosen, and ten larvae were randomly collected from each colony. DNA was analyzed by using three different primer combinations producing 61, 63, 63 polymorphic markers, respectively. All larvae exhibited different banding patterns from one another, illustrating the prominent role of sexual reproduction for the production of larvae. Nei's mean genetic distances for all 12 possible pair-wise combinations for larval origins revealed, in most cases, that sister larvae are genetically closer than larvae from different colonies and that larvae may be grouped into three statistical clusters in accordance with colony origin and population studied. The usefulness of molecular methodologies in coral population genetics is discussed.