Tiny Shrimp Are the Bees of the Sea

Caridean shrimp like this one carry pollen between male and female sea grass flowers. Image Credit: Enrique Dans via Wikimedia Commons // CC BY-SA 2.0.

Just when you thought nature couldn’t get any more adorable, there’s this. Scientists have discovered that teensy shrimp, jellies, and other sea creatures act as pollinators for underwater plants. They described the sea bees’ activity in the journal Nature Communications.

The sea grass Thalassia testudinum, also known as turtle grass, grows in dense meadows in the shallows of the Caribbean and the Gulf of Mexico. The grass puts out little white and pale pink flowers, some (male flowers) giving off pollen and others (female flowers) accepting it. Scientists have long believed that turtle grass pollinates itself by simply releasing its pollen into the water, which washes it into receptive female flowers.

Those scientists were correct. But the grass also seems to make use of its little visitors, as researchers learned when they trained video cameras on a flowering meadow. They discovered that the meadow was a bustling place frequented by dozens of different species [PDF], from shrimp and crabs to jellies, isopods, and worms.

Analysis of the recordings also revealed an interesting trend: male flowers full of pollen were far more popular with crustacean visitors than those without. The researchers watched as the tiny animals fed from the male flowers and swam away, grains of pollen still stuck to their bodies. The situation looked awfully familiar. Was it possible that the animals serve the same role underwater as bees do on land?

To find out, the researchers carefully collected flowering turtle grass and a sampling of its animal visitors, then brought them all into the lab. They set up a series of trays, each containing a single pollen-rich male and a single female flower, then added the trays to small aquaria teeming with their regular customers. They also ran a second experiment, in which the two flowers were buffeted by different types and strengths of current.

The researchers’ hypothesis was spot-on: The little animals were indeed ferrying grains of pollen from male to female flowers, allowing the flowers to get it on even in the absence of strong currents.

Kelly Darnell of The Water Institute of the Gulf was unaffiliated with the study, but told New Scientist she was excited with its findings.

"That pollination by animals can occur adds an entirely new level of complexity to the system," she said, "and describes a very interesting plant-animal interaction that hasn’t really fully been described before."

Turtle grass can also reproduce asexually, so pollination via shrimp likely represents a pretty small portion of its sex (or sexless) life. But the fact that it happens at all is delightful enough for us.

NUS Environmental Research Institute, Subnero
Researchers in Singapore Deploy Robot Swans to Test Water Quality
NUS Environmental Research Institute, Subnero
NUS Environmental Research Institute, Subnero

There's something peculiar about the new swans floating around reservoirs in Singapore. They drift across the water like normal birds, but upon closer inspection, onlookers will find they're not birds at all: They're cleverly disguised robots designed to test the quality of the city's water.

As Dezeen reports, the high-tech waterfowl, dubbed NUSwan (New Smart Water Assessment Network), are the work of researchers at the National University of Singapore [PDF]. The team invented the devices as a way to tackle the challenges of maintaining an urban water source. "Water bodies are exposed to varying sources of pollutants from urban run-offs and industries," they write in a statement. "Several methods and protocols in monitoring pollutants are already in place. However, the boundaries of extensive assessment for the water bodies are limited by labor intensive and resource exhaustive methods."

By building water assessment technology into a plastic swan, they're able to analyze the quality of the reservoirs cheaply and discreetly. Sensors on the robots' undersides measure factors like dissolved oxygen and chlorophyll levels. The swans wirelessly transmit whatever data they collect to the command center on land, and based on what they send, human pilots can remotely tweak the robots' performance in real time. The hope is that the simple, adaptable technology will allow researchers to take smarter samples and better understand the impact of the reservoir's micro-ecosystem on water quality.

Man placing robotic swan in water.
NUS Environmental Research Institute, Subnero

This isn't the first time humans have used robots disguised as animals as tools for studying nature. Check out this clip from the BBC series Spy in the Wild for an idea of just how realistic these robots can get.

[h/t Dezeen]

There May Be an Ancient Reason Why Your Dog Eats Poop

Dogs aren't known for their picky taste in food, but some pups go beyond the normal trash hunting and start rooting around in poop, whether it be their own or a friend's. Just why dogs exhibit this behavior is a scientific mystery. Only some dogs do it, and researchers aren't quite sure where the impulse comes from. But if your dog is a poop eater, it's nearly impossible to steer them away from their favorite feces.

A new study in the journal Veterinary Medicine and Science, spotted by The Washington Post, presents a new theory for what scientists call "canine conspecific coprophagy," or dogs eating dog poop.

In online surveys about domestic dogs' poop-eating habits completed by thousands of pet owners, the researchers found no link between eating poop and a dog's sex, house training, compulsive behavior, or the style of mothering they received as puppies. However, they did find one common link between the poop eaters. Most tended to eat only poop that was less than two days old. According to their data, 85 percent of poop-eaters only go for the fresh stuff.

That timeline is important because it tracks with the lifespan of parasites. And this led the researchers to the following hypothesis: that eating poop is a holdover behavior from domestic dogs' ancestors, who may have had a decent reason to tuck into their friends' poop.

Since their poop has a high chance of containing intestinal parasites, wolves poop far from their dens. But if a sick wolf doesn't quite make it out of the den in time, they might do their business too close to home. A healthier wolf might eat this poop, but the parasite eggs wouldn't have hatched within the first day or two of the feces being dropped. Thus, the healthy wolf would carry the risk of infection away from the den, depositing the eggs they had consumed away in their own, subsequent bowel movements at an appropriate distance before the eggs had the chance to hatch into larvae and transmit the parasite to the pack.

Domestic dogs may just be enacting this behavior instinctively—only for them, there isn't as much danger of them picking up a parasite at home. However, the theory isn't foolproof. The surveys also found that so-called "greedy eaters" were more likely to eat feces than dogs who aren't quite so intense about food. So yes, it could still be about a poop-loving palate.

But really, it's much more pleasant to think about the behavior as a parasite-protection measure than our best pals foraging for a delicious fecal snack. 

[h/t The Washington Post]


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