Growth characteristics of the hybrid between pinto abalone, Haliotis kamtschatkana Jonas, and ezo abalone, H. discus hannai Ino, under high and low temperature

Rearing experiments have been done to compare growth rates in pinto abalone, Haliotis kamtschatkana Jonas, and ezo abalone, H. discus hannai Ino. The growth rate in shell length of juvenile pinto abalone was superior to that of ezo abalone at water temperatures below 7°C. However, the growth rate declined above 17°C and was lower than that of ezo abalone. The hybrid cross between the female of ezo abalone and the male of pinto abalone was obtained but with low fertilization (20%). The reciprocal cross was never successful. The growth rate of the hybrid was superior to the parental species below 18°C and moderate between parental species under 8°C. Isozymic analysis confirmed that genetic hybridization occurred in this cross, on the basis of the results of electropherograms of the hybrid and its parental species.