Development of species-specific markers of the tropical oyster (Crassostrea belcheri) in Thailand

Randomly amplified polymorphic DNA (RAPD) analysis was used to identify spe cies-specific markers of 5 oyster species in Thailand: Crassostrea belcheri , Crassostrea iredalei, Saccostrea cucullata, Saccostrea forskali, and Stri ostrea (Parastriostrea) mytiloides. Species-specific markers were found in C. belcheri, C. iredalei, and S. cucullata but not in S. forskali and S. my tiloides. Three C. belchet-specific RAPD fragments were cloned and sequence d. A primer set was designed from each of the recombinant clones (pPACB1, p PACB2, and pPACB3). The polymerase chain reaction products showed expected sizes of 536, 600, and 500 bp, respectively, with the sensitivity of detect ion approximately 30 pg of C. belcheri total DNA template. The specificity of pPACB1 was examined against 135 individuals of indigenous oyster species in Thailand and against outgroup references S. commercialis (N = 12) and P erna viridis (N = 12). Results indicated the species-specific nature of pri mers developed from pPACB1. This primer set can be used for broodstock sele ction and determination of C. belcheri larvae to assist the selective breed ing program for this commercially important species.