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Diving Videos

Monthly Archives: December 2014

REMORAS | SEA LIFE WITH A GOOD SUCKER | A DIVE BUDDY THAT STICKS TO YOU

Diving Videos

Remora remora is the name for the common remora. They have a highly modified dorsal fin that expands during their development to become an efficient sucker disk on the top of their head. Remoras attach to sharks, mantas, whales, turtles, ships, divers and just about anything to save energy until their next feed. It’s hard to imagine that powerful, open ocean swimmers like mahi-mahi [dolphinfish] and amberjacks are related to remoras. Your opinion about these opportunistic freeloaders might change when you consider what 50 million years of evolution has done by tinkering with the muscles and bone structure of a dorsal fin to produce their quirky edge for survival.

In nature there are relationships like predator-prey and parasitism where one half of the equation benefits at the expense of the other. There is mutualism, a form of symbiosis where both organisms benefit from the relationship to the extreme where one cannot survive without the other. Commensalism describes relationships on a scale between parasitism and mutualism. Where does the relationship between remoras and other sea life belong?

Does the removal of parasites as a service to a host improve survival, longevity or the energy budget of a host like this humpback whale? It must have a hundred or more remoras that increases the effort needed to move through the ocean using precious fat reserves for energy. This mother is feeding its calf on the long journey to summer feeding grounds off Antarctica, so how far south do remoras go before their free ride gets too cool to survive? Do remoras provide a parasite removal service that is worthy of them tagging along or is this an extreme form of commensalism that’s nudging parasitism as a way of life? Remoras are up their with platypus and other anomalies of the natural world that make me wonder what the creator was on while doodling the prototype or was the design brief given to a committee? Continue reading

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