Researching the Lionfish Invasion

The lionfish invasion has come to Florida and is starting to impact biodiversity. Lionfish are an invasive species and therefore have no natural predators. They have the ability to expand their range, which has been critical in the light of climate change.

In order to understand how the Indo-Pacific species was able to feed in ranges outside its native temperature and contribute to a lionfish invasion in places like Florida, marine biology senior Kristin Treat investigated the thermal response of the two phases, expansive and compressive, of feeding performance in lionfish.

Treat’s research addresses two major questions: Does the effect of temperature on kinematic speed (its trajectory) differ between the expansive and compressive phases of feeding in lion fish; and does the effect of temperature on kinematic speed change through lionfish’s development?

The rate at which lionfish’s jaws move from the expansive phase to the compressive phase as fish captures its prey is determined by the speed of muscular contraction. However, there are two sets of muscles involved in one feeding event; one drives the fast-paced expansive phase and the other drives the slow-paced compressive phase.

Treat compared the velocity of jaw movement of 13 lionfish from three size classes during the expansive and compressive phases of a feeding event. Her results concluded that kinematic speed is faster in the expansive phase compared to the compressive phase of feeding in lion fish.

However, at each fish-size class, the thermal response of kinematic speed had no significant difference between the expansive and compressive phases of feeding. An interesting result Treat found was large lionfish are more sensitive to temperature than medium and small lionfish.

Treats results show that lionfish can still feed effectively in various temperature regimes.

“Actin and myosin are both protein filaments that make up muscle, but these proteins will not form out of their optimal temperature range,” Treat said. “It is thought however, that when lionfish go outside of their optimal temperature range, they accumulate proteins called heat shock proteins that as a buffer and protect actin and myosin from being deformed.”

Treat said this idea would be an important project in the future to conduct because it might be the underlying molecular cause as to why lionfish can feed in thermally variable environments.

Treat’s research has been a great experience for her. She plans to go to grad school after she graduates this year.

“It is a great way to gain experience for future jobs or grad school,” Treat said. “It also helps build your public speaking, communication and leadership skills.”

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