Abstract: | Sea cucumber (Apostichopus japonicus) has become one of the major aquacultural species in China. Genetic improved seeds of sea cucumber play a key role in the ever-increasing profit. Information on the genetic parameters of papillae number, the important economic trait of sea cucumber, however, has been lacking. To investigate the repeatability, required measure times, and the most probable producing ability (MPPA) of sea cucumber, we applied quantitative genetic methods to determine the repeatability coefficients of papillae number of four sea cucumber populations in the age of 12–17 month, including Korean self-propagated population (KK), Duoci self-propagated population (DD), Shandong self-propagated population (SS), and Three-way cross population (DK). Based on the estimates, we also calculated and compared the required measure times, MPPA, and correlation efficient between MPPA and body weight of the four populations. We found that the repeatability coefficients of papillae number were low in all four populations. The repeatability coefficients of the four population followed the order:DD(0.29)>DK(0.28)>SS(0.20)>KK(0.19). For population DD and DK, the papillae number needed to be measured for 5 times to reach a relative accuracy above 80%, while for SS and KK populations 8 measure times were required. The MPPA for papillae number followed the order: DD(41.3)>DK(40.8)> KK(39.8)>SS(39.1), with the significant difference between DD and SS only (P<0.05). The phenotype correlation between MPPA and body weight in each population was significantly positive. Therefore, repeatability and MPPA could be used as criteria in population selection for papillae number. Our results suggested that DD and DK populations might have higher papillae numbers, higher potential for selection, and less measure times needed than the other two populations, hence they could be the key populations for papillae number selection. |