After the 2010 Football World Cup, no one would ask about the connection between football and octopuses. Paul, the psychic octopus, saw to that.
But what could be the connection between an octopus, psychic or otherwise, and coconuts? That was precisely what scientists A Bijukumar and V Sreeja of the Kerala University’s Aquatic Biology Department set out to study.
What they found was mind-blowing, to say the least. The octopuses found coconut shells to be excellent props for a kind of crazy walking, as tools in defence as well as offence, to hide, and most surprisingly, even to lay eggs.
The behavioural peculiarities were studied by observing the behaviour of two female and three male specimens of the veined octopus or Amphioctopus marginatus, that were collected live from Vizhinjam Bay.
For the first time ever, the scientists also found that the crabs carried away coconut shells, manipulated two shells together and used it for laying eggs as festoons hung across the two shells.
“This was the first report on octopus using coconut shell as a place for laying eggs and we published our observations in the ‘Journal of Threatened Taxa’”, said A Bijukumar, head of the KU Department of Aquatic Biology. “This animal is the only invertebrate which is known to use tools, and this is considered as a benchmark for cognitive sophistication,” said Bijukumar.
“The necessity to correctly assemble the two separate coconut shells in order to create a single functioning tool sets this example of tool use apart from most of all examples previously known for invertebrates,” he added.
What is even more interesting is the fact that while carrying the coconut shells, the octopus exhibits strange behaviour such as stilt walking and bipedal locomotion instead of the usual crawling with arms, and using the suckers to push and pull the animal along. “In bipedal locomotion, the octopuses used two arms for locomotion and the remaining arms to provide camouflage. In stilt walking, the arms were used as rigid limbs,” said Bijukumar.
This was in addition to the usual methods of defence such as camouflage, where they merge with the background and methods of offence such as crypsis, where it uses a flash of colours to confuse the predator or modify its appearance to resemble swimming fish, rocks or other objects.
However, the most significant finding was that of making a house out of coconut shells and laying of eggs in them. The octopus squatted directly over the eggs, holding the coconut shell firmly with a few suckers and waving the free arms across the eggs, thus constantly aerating the eggs. The octopus accepted food on the first day of egg-laying, whereas it avoided food subsequently.
Starved yes, but weak, no way. Try approaching the coconut shell and the ‘ma-octopus’ would squirt strong jets of water through the funnel. Try touching the eggs, it would be ink that gets squirted at you. The scientists collected a total of 22 festoons from coconut shell with the number of eggs going up to 20,000.
The scientists believe that the coconut-shell carrying behaviour is likely to have formed when the supply of large empty bivalve shells decreased and supply of clean and light coconut shell halves discarded by the coastal human communities and tourists increased.
It looks like the octopuses are going to use coconut shells as nutty homes, for a long time to come.