'Ghost' fish taking over the Caribbean

Oct 18, 2013

(Phys.org) —A spiny, toxic and beautiful member of the world's coral reef communities, the Red Lionfish is invisible to the small fish it likes to eat.

A new study by James Cook University scientists Oona Lönnstedt and Professor Mark McCormick suggests this is one reason for the lionfishes' incredible success in the Caribbean, where it is eating its way through the reef ecosystem.

"Lionfish are native to the Pacific, but have been taking over the Caribbean Basin ever since they were accidentally introduced almost 30 years ago," Professor McCormick said.

"Their extreme success as an invasive predator has long been a mystery to ecologists worldwide."

The new research, published in the latest issue of PLoS ONE suggests that the solution in part lies in the power of camouflage, as these voracious carnivores are virtually undetectable by small fish.

Red lionfish (Pterois volitans) are a rare and beautiful sighting for divers in their native waters around the Great Barrier Reef, but in the reefs around the Florida coast and Caribbean they are viewed as a huge nuisance.

"For over a decade, scientists have tried their best to understand how these gorgeous but deadly can wreak such havoc on their invaded ecosystem," Professor McCormick said.

"Almost all of the work to date has focussed on the consequences of the interaction between these predators and their prey in areas where lionfish are invasive species."

Now, as a world first, graduate student Ms Lönnstedt and Professor McCormick have found that lionfish are undetectable by prey, acting as ghosts able to feed on anything and everything without being discovered until it's too late.

"We tested the response of small prey fish to three different predators, one of them the lionfish," Ms Lönnstedt said.

"Surprisingly, the common prey fish were unable to learn that the lionfish represented a threat, which was very different to their response to two other fish predators.

"Lionfish were able to sneak up on their prey and capture every single one, while the other predators had much lower feeding success."

This ability to bypass a very well-studied learning mechanism commonly used by prey to learn new risks is a world first, and has in part lead to the astounding success of lionfish in the Caribbean.

With release from any natural enemies in their new system and no problem catching food, the lionfish are practically unstoppable.

The paper 'Ultimate Predators: have evolved to circumvent prey risk assessment abilities' is published in the latest issue of PLOS ONE.

Explore further: Bodies of 500 sea lions found on Peruvian beach

More information: dx.plos.org/10.1371/journal.pone.0075781

add to favorites email to friend print save as pdf

Related Stories

Lionfish found following the current trend

Jun 28, 2013

In findings published today in the Marine Ecology Progress Series, researchers have found that ocean currents may explain why the Indo-Pacific lionfish Pterois volitans living in the Atlantic is yet to mak ...

Recommended for you

Seychelles poachers go nutty for erotic shaped seed

22 hours ago

Under cover of darkness in the steamy jungles of the Seychelles thieves creep out to harvest the sizeable and valuable nuts of the famous coco de mer palm, and their activities are threatening its long-term ...

Laser scanning accurately 'weighs' trees

Nov 21, 2014

A terrestrial laser scanning technique that allows the structure of vegetation to be 3D-mapped to the millimetre is more accurate in determining the biomass of trees and carbon stocks in forests than current ...

Cameras detect 'extinct' wallabies near Broome

Nov 21, 2014

Yawuru Country Managers have found a spectacled hare wallaby (Lagorchestes conspicillatus) population, a species which for the last decade was feared to be locally extinct at Roebuck Plains, adjacent to Broome.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.