Natures wonders: travelling econiche (Introduction)

by David Turell , Sunday, August 02, 2020, 19:14 (1572 days ago) @ David Turell

Loggerhead turtles travel the world and spread species of life that cannot move on their own:

http://oceans.nautil.us/feature/592/theres-a-world-living-on-every-loggerhead?mc_cid=4f...

"...hitchhikers, known as epibionts, show up on hosts from crabs to crocodiles. But according to a May 2020 paper by Ingels, Valdes, dos Santos and others, loggerheads in particular carry many, many more of them than previously thought—often tens of thousands of individuals each. These represent a diversity of species and life stages, and turn a well-populated turtle into “a little metropolis floating in the ocean,” says Ingels.

***

"Ingels and his colleagues study meiofauna. It's a group characterized chiefly by size: Anyone who falls between the mesh of a one-millimeter sieve—but can't pass through a 32-micron one, with holes one-third as wide as a dollar bill is thick—is a member.

This encompasses "a huge diversity" of animals, from shrimplike amphipods to fork-tailed gastrotricha, says Ingels. "We're talking hundreds of thousands of species, potentially.”

***

"The average turtle, they found, housed tens of thousands of individual hangers-on. (One had nearly 150,000.) And the number of life stages represented, from eggs and juveniles to gravid females and adults, suggested most were living out their whole lives on the loggerheads—eating and mating, dying and being born.

"The findings help to shed light on the question about how particular types of meiofauna—most of whom can't swim—have nonetheless spread across the world. The same species are found "thousands of kilometers apart," Ingels says. "How did they get there?" Many are probably caught up in currents, snarled in sargasso weeds or trapped in floating ice. But "I think we've shown with this paper that turtles play an extraordinary role," says Ingels.

"Evidence is mounting that, once meiofauna are established in a habitat, they help out with nutrient cycling, work with sediments, graze on microbes and provide food for larger creatures, but researchers aren't quite sure how the turtles themselves are affected by the responsibility of ferrying them around. A rich, mucky layer of epibionts may help to camouflage the turtles from sharks and other predators that look down from above. But the drag this load creates might slow the turtles down, and larger hangers-on, like barnacles, are known to damage shells and cause infection.

"The researchers hope that, as we learn more about how loggerheads carry and disperse other creatures, it will inspire more support for their protection. "They are not only cute," says dos Santos. "They have been traveling around with these communities on their backs.'"

Comment: this shows how interconnected the whole vast bush of life actually is and how necessary it all is to each and every branch. dhw doesn't seem to understand it had to be built over time as part of the goal of creating humans.