Collaborating creatures

Hitching a ride

Eagle-eyed biologist Charlotte Havermans was aboard the German research icebreaker Polarstern in the Southern Ocean a couple of years ago when she spied something unexpected. She was sampling for zooplankton, tiny critters found not far from the water’s surface that drift along with the current, when she came across a peculiar pair: A type of crustacean called an amphipod and a teeny, tiny pteropod, or sea snail. The hitchhiking pteropod, Spongiobranchaea australis, was awkwardly riding atop the amphipod, Hyperiella antarctica, much to Havermans’s amusement. “It looked like a school kid constantly adjusting his backpack on his back,” she tells Newscripts. After adjusting the pteropod with its legs, “the amphipod then swam really fast, and then did this readjusting and swimming over and over again. I couldn’t stop watching it and smiling.” The voyage, which covered a route from Cape Town to Antarctica, was around Christmastime, and Havermans recalls this being, by far, her cutest gift that year.

Similar relationships had already been observed, but never in the open waters of the Southern Ocean. Havermans drew from the work of other groups to hypothesize that the voyaging pteropod is protecting its free ride by producing a chemical to which its host, but not its host’s predators, is immune (Mar. Biodiversity 2018, DOI: 10.1007/s12526-018-0916-3). Havermans is now on the hunt to determine if S. australis produces a fish-deterring chemical like that excreted by a previously discovered pteropod and to investigate how specialized these symbiotic relationships truly are.

Havermans believes that we have only scratched the surface when it comes to finding symbiotic relationships such as these. As researchers continue to haul nets out of the freezing Arctic waters, blind to all but the animals on which they focus their research, Havermans wonders, “How many other small animals are doing similar things which we just overlook because we are not searching for them?”

Bacteria keep bees buzzing

Back on land, another symbiotic relationship protects the health of a popular pollinator—the humble bumblebee.

“Microbiome” has become a buzzword, with ongoing research on how it affects weight, susceptibility to neurodevelopmental conditions, and immune system function, to name just a few areas.

But what about bees’ microbiomes? Recently, researchers found evidence that a lactic acid-producing bacterium, Lactobacillus bombicola, in the guts of our buzzing buddies may be of the utmost importance for their survival (Parasitology 2018, DOI: 10.1017/s0031182018001555). When a team led by Evan Palmer-Young of the University of California, Riverside, grew L. bombicola in a petri dish, the bacterium caused a pH drop that created an environment acidic enough to prevent parasites from growing. According to Palmer-Young, these results indicate the importance of the symbiont in the bee gut creating a low-pH environment and making opportunistic colonizers buzz off.

Although this particular work was done in vitro, Palmer-Young is no newbie when it comes to working with—and getting stung by—live bees. For other research he has to nab bees out of their colony under red light. Bees aren’t able to detect red light well, and that keeps experimenting scientists like Palmer-Young from disturbing them. “It feels like Halloween, with the buzzing of insects and eerie dim red light,” he tells Newscripts. And the aftermath of a sting is more of a pain than the sting itself. “If I am doing a big experiment, it’s an annoyance to have my fingers swollen because they become even less dexterous than normal,” he says. “My students seem to get along much better with these tasks than I do.”

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