To obtain geographical range and growth–kinetics parameters of mottled sake (Beringraja pulchra) populations in the Yellow Sea, three mark–recapture experiments were carried out. Overall, 991 tagged individuals were released, and 4.1% of them were recaptured with the mean release period of 339 d (range, 8–1,420 d) and the mean growth rate of 1.4 cm mon–1 (female, 1.5 cm mon–1; male 1.3 cm mon–1). In the first experiment, 667 individuals were released at Heuksan Island from April to June, 2007–2009, and 30 individuals were recaptured mainly at the north and the north–east coasts of the island, indicating absence of migration to the south of the island. In the second experiment, 323 individuals were released at several fishing grounds scattered in the Yellow Sea in 2010–2013, and 11 individuals were recaptured at points deviated to all directions from the releasing points. As the last, one individual was released with pop–up satellite archival tag at a costal point (34°37.2’N, 124°59.3’E) off Hong Island on May 21, 2010. The tagged individual migrated to a north–east location (35°50.4’N, 126°03.6’E) of Eocheong Island by Aug. 25, 2010. The data archived for the three months in the tag indicated that the migration path had depths of 48–80 m and temperature of 12.6–14.4°C. The results indicated that mottled sake populations had a localized habitat ranges at the north of Heuksan Island and the west of Hong Island while growing at the rate of 1.4 cm mon–1.

The gonadsomatic index (GSI) of mottled skate was the highest in April, GSI and HSI showed a reverse phase for its reproductive cycle. The fish had one pair of egg capsules, having 1 to 7 fertilized eggs, and spawned all the year round. When surveying the reproductive characteristics of females over 63 ㎝ in disc width, we found the spawning peak was between April to June, and the appearance ratio of egg capsules was the highest in May (32.1%). The eggs were hatched at 8℃, 13℃, 18℃, water temperature (12.8 to 24.2℃), and the best hatching temperature was 18℃. The number of fish hatched was 4 to 5 fish/egg capsules, and the hatching rate was 100%. The sex ratios of hatching larvae were 45.5% female and 54.5% male. Therefore this study will provide fundamental data and information for artificial reproduction of the mottled skate.