Identification of Girella punctata and G-leonina by PCR-RFLP analysis

Two Girella species, Girella punctata and G. leonina, are sympatric sister species with an extensive overlap in their respective distributions on shallow rocky reefs from Hong Kong to the south of the Japanese Islands. Juveniles of the two species cannot be discriminated easily on the basis of external characters. In this study, after morphological identification of the species, sequencing analysis was carried out for the partial 16S ribosomal RNA gene and for the D-loop region in mitochondrial DNA. A total of 109 specimens were examined. Restriction site mapping of the sequences suggested that the electrophoretic patterns of polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) analysis of the gene products would produce a species-specific banding pattern. Subsequently, the PCR-RFLP analysis showed that the method was as effective for separating the two morphologically similar species of the genus Girella as the sequencing analysis.