Jon123
01-21-2007, 08:06 PM
Groupers and moray eels hunt cooperatively
Groupers and Giant moray eels use interspecific and communicative hunting, according to a recent scientific paper.
Plectropomus pessuliferus and Gymnothorax javanicus have been observed working with each other to catch prey in the Red Sea.
Their normal hunting strategies are quite different. Groupers are semi-benthic piscivores, which hunt in open water. Moray eels sneak through crevices to corner their prey in holes.
Prey avoid eel predation by swimming into open water, and avoid grouper predation by hiding in crevices.
A coordinated hunt confronts prey with a multipredator attack that is difficult to avoid.
Observations
Underwater filming revealed that both partners benefited from the association.
Groupers and morays caught almost five times more prey through mutual hunting. Moray eels hunting alone were never successful when observed.
The partner that successfully caught and ate the fish was not showed any aggression from the unsuccessful partner. Groupers initiated the hunt by visiting the giant eels and shaking their heads vigorously.
The head is shaken three to six times a second just a few centimetres in front of the moray's head, and the soft part of the dorsal fin is erected.
The morays respond by leaving their crevices, with the moray and grouper then swimming off across the reef.
The fish would stay together from a few seconds up to 44 minutes.
In addition to signalling before any hunting events, groupers also recruited morays after unsuccessful hunts.
In unsuccessful hunts, morays would be visited and signalled to for assistance. The moray would respond by attempting to guide the prey to the grouper.
Signalling is motivated by hunger
Hunts were initiated by groupers getting hungry, according to the paper.
Six groupers who were fed fish were observed not to go off and hunt during a 120 minute filming period.
Groupers have also been observed hunting prey simultaneously with Napolean wrasse, Cheilinus undulatus.
Fulfilling a similar role to the moray eel, the wrasse cannot enter crevices where prey is hiding, but uses its jaws to destroy the hiding place instead.
Intraspecific group hunting has received considerable attention because of the close links between cooperative behaviour and its cognitive demands.
Jon
Groupers and Giant moray eels use interspecific and communicative hunting, according to a recent scientific paper.
Plectropomus pessuliferus and Gymnothorax javanicus have been observed working with each other to catch prey in the Red Sea.
Their normal hunting strategies are quite different. Groupers are semi-benthic piscivores, which hunt in open water. Moray eels sneak through crevices to corner their prey in holes.
Prey avoid eel predation by swimming into open water, and avoid grouper predation by hiding in crevices.
A coordinated hunt confronts prey with a multipredator attack that is difficult to avoid.
Observations
Underwater filming revealed that both partners benefited from the association.
Groupers and morays caught almost five times more prey through mutual hunting. Moray eels hunting alone were never successful when observed.
The partner that successfully caught and ate the fish was not showed any aggression from the unsuccessful partner. Groupers initiated the hunt by visiting the giant eels and shaking their heads vigorously.
The head is shaken three to six times a second just a few centimetres in front of the moray's head, and the soft part of the dorsal fin is erected.
The morays respond by leaving their crevices, with the moray and grouper then swimming off across the reef.
The fish would stay together from a few seconds up to 44 minutes.
In addition to signalling before any hunting events, groupers also recruited morays after unsuccessful hunts.
In unsuccessful hunts, morays would be visited and signalled to for assistance. The moray would respond by attempting to guide the prey to the grouper.
Signalling is motivated by hunger
Hunts were initiated by groupers getting hungry, according to the paper.
Six groupers who were fed fish were observed not to go off and hunt during a 120 minute filming period.
Groupers have also been observed hunting prey simultaneously with Napolean wrasse, Cheilinus undulatus.
Fulfilling a similar role to the moray eel, the wrasse cannot enter crevices where prey is hiding, but uses its jaws to destroy the hiding place instead.
Intraspecific group hunting has received considerable attention because of the close links between cooperative behaviour and its cognitive demands.
Jon