A team has studied the mountainous star coral, Orbicella faveolata, to determine whether coral populations that have survived higher temperatures can pass their heat tolerance on to their offspring.  To the scientists' surprise, the results showed the opposite: The offspring from a population that is less heat-tolerant performed better when exposed to high temperatures than their counterparts from a heat-tolerant population. The findings counter the commonly held notion among scientists that if coral parents can handle the heat, so should their offspring.

 

The researchers carefully bred the corals in a controlled environment and exposed the coral larvae to heat stress conditions in the lab. The researchers then measured how the corals survived. They also examined the activity of the coral genes to see whether they could detect signs of stress at higher temperatures. The unexpected finding that coral larvae from the less heat-tolerant population survived better and showed fewer signs of stress suggests that the ability of coral offspring to handle heat might be influenced by various factors, including whether and how often their parents have bleached in the past or suffered other environmental pressures.