Abstract:Scapharca broughtonii (Mollusca, Bivalve, Arcoida), one of the most important commercial marine bivalve species, is mainly distributed on the coasts of the Bohai Sea, and north of the Yellow Sea, China. With the deterioration of marine ecological environments resulting from the extended farming scale and frequency of human activities in coastal waters, and over-fishing, wild resources have decreased. Mass mortality has become a major constraint for the development of S. broughtonii culture. The hybridization of different populations has proven to be a good breeding method. Intraspecific hybridization was investigated using two stocks of S. broughtonii; the China population (C) and the Korea population (K). The shell length and wet weight were compared between two reciprocal hybrid crosses (C♀ × K♂, CK and K♀ × C♂, KC) and two parental groups (C♀ × C♂, CC and K♀ × K♂, KK) during the adult culture stage. The results showed that the shell length and wet weight of the KC group were significantly higher than those of the other three groups. The heterosis rates of the CK group for shell length was between –2.03% and 5.44%, and the KC group was between 4.40% and 14.74%. The heterosis rates of the CK group for wet weight was between 1.41% and 7.71%, and the KC group was between 5.32% and 23.71%. The heterosis rates of the KC group for shell length and wet weight was higher than those of CK group. The wet weight of the CK group was significantly higher than that of the CC and KK groups at 14 and 15 months, respectively. Additionally, the heterosis rate of the two reciprocal hybrid crosses for wet weight was positive and high. In summary, the heterosis rates of the KC group for shell length and wet weight were markedly higher than those of other three groups, thus, the KC hybrid group could be selected as an ideal breeding material.
