1.James McClintock Was Studying the chemical ecology of sponges in Antarctica when he witnessed the kidnapping. It happened just beneath the ice of McMurdo Sound
2.The victim was a sea butterfly , “a little snail, bright orange, swimming around in the water with no shell to protect it, like a miniature angel flapping its wings”, McClintock says. The butterfly’s abductor was a shrimplike creature called an amphipod, which,at a quarter inch long was twice its victim’s size. The amphipod swam up, seized the butterfly with 4 of its 14 legs and rotated it around to its back like it was slinging on backpack” , McClintock recalls. Then , holding the butterfly firmly on its back, the amphipod swam off.
3.McClintock , a biologist at the University of Alabama in Birmingham , saw hundreds of these abductions once he and colleague, John Janssen of Loyola University of Chicago, started looking for them; they estimate that the kidnapping happen thousands of time each day. The seizures appear to characterize a previously unknown biological relationship –neither parasitism, in which on party benefits and other loses .nor mutualism , in which both benefits . In this case the amphipod gets something from its hostage, but the butterfly neither gains nor loss .
4.What the amphipod gets its protection . Its bigger and faster than its victim, but its lacks defense against predator fish. Sea butterflies. however , carry bitter-tasting chemicals , so fish leave them alone. And when amphipod is holding a butterfly hostage “ like a little backpack of poison”, in McClintock’s words-even hungry fish avoid them both.
5.To learn exactly how distasteful the butterfly ‘s defense system is , McClintock prepared some butterfly biscuits. The fish spit out the butterfly biscuits. Then he did a taste test himself biscuits. It’s really bad “, he reports.”You want its off your tongue immediately.”
6. McClintock next captured some butterfly, amphipods, and fish and put them all together in a tank . “ If the amphipod is carrying a butterfly , it’s protected,” he says and the fish give them a wide berth. “ Whereas if you pull the butterfly off, the amphipod becomes lunch. There doesn’t seem to be anything else in nature that actively pursues, captures, and carries another to obtain the benefit of the hostage ‘s chemical defenses. It’s surprising.’
7. The marauding amphipod is clearly carrying out its protection scheme deliberately. Predator fish rely on their sight to hunt amphipods, and the researchers note that more butterfly abductions took Place near the surface, where is light, than in deeper ,darker water. As many as 75 percent of the amphipods near the surface were toting butterflies on their back , but deeper down as few as 10 percent were doing so.” if you ‘re an amphipods where a fish can see you.
8. Carrying their protective load around with them reduced the amphipods’ swimming speed, the biologists found, and thus limited their ability to catch and eat the other small crustaceans on which they feed .But apparently amphipods find the trade-off worthwhile.
9. The butterfly , on the other hand ,appear to gain absolutely nothing from the experience . when captured, they retract into a ball,pull in their wings. stop feeding, and simply sit there . Yet they don’t seem to suffer , either .They ‘re evidently able to ingest some dissolved nutrients from the sea through their body walls. The researchers never found a dead butterfly in captivity, and whenever they pulled one from its captor’s grasp, says McClintock,” it always opened up its wings and swam off.” That , he says, indicates that the amphipods periodically release and replace their hostage which may mean that sea butterfly gain their freedom only to be shanghaied again another day.