What happens if you give decorator crabs access to fluffy pom-poms? The animals will look like Christmas. But there is method to their seasonal attire.
Image: Rohan Brooker
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Christmas is known as the season in which oh-so-many people appear to develop a strange longing to dress in colorful patterned jumpers that wouldn't stand a chance throughout the rest of the year. It is athing.
Camposcia retusa or decorator crabs, as they are more commonly known, do things differently. Though, as their name suggests, they enjoy dressing up - using objects from their environment - they at least have a reason for it.
Fluffy little balls
This desire to adorn themselves, makes the crabs much loved among marine scientists. Usually they would choose to dress up in sponges, algae and marine debris, but as Danielle Dixson and her team from the University of Delaware found out during recent research, they don't shy away from pom-poms that give them a more festive look.
The team of scientists, which included undergraduate students, ran a series of experiments in which crabs were placed in individual containers and provided with green and red Christmas-style pom-poms.
"We chose to use craft pom poms because they were light enough that the crab would be able to use them and we can easily manipulate them in terms of color and size," says Dixson. The colors used in the study were simply based on the pom-poms that were available at a store in multiple sizes, she adds.
The make-up
Half the crabs were given shelters. Dixson wanted to know if there was any difference between the speed and manner of decoration if the crabs had a place to hide. During the course of a full day, the team took photos every 60 minutes for the first 12 hours, and again at the end of the 24 hour period.
They found that all of the crabs were fully decorated within 24 hours. Most were in fact decorated within six hours of having access to the pom-poms.
"This indicates the importance of the decorating behavior", Dixson says. "They also decorate their legs before they decorate their body."
Species that use decoration usually cover the body first to protect their vital organs, like the larvae of many caddisfly species that build hard cases from whatever material they find, or assassin bugs who have the odd habit of carrying a shield of ant carcasses - their number one prey - to avoid being eaten by predators.
The crabs that were given shelter were in a hurry to first decorate whichever legs did not fit inside - because they were more exposed.
In the end, both humans and crabs share a certain danger by decoration: The crustaceans, when all dressed-up, require more energy to move around, and eventually become too slow to escape predators, while humans are at risk to be bullied by Christmas humbugs for wearing something really ugly. Happy holidays.
The top 10 natural oddities in pictures
While many animals and plants are at risk of extinction, new species are constantly emerging. Researchers have presented the ten most curious discoveries from the past year. Take a look at our gallery.
Image: picture-alliance/dpa/R. Bolland/SUNY College of Environmental Science and Forestry
The stranger the better
Scientists at Syracuse University in New York chose the ten strangest new plants and animals from a pool of hundreds. They based their decisions on animals with peculiar habits or striking physical characteristics. This spider, which has been called "Cebrennus rechenbergi", escapes predators by doing cartwheels.
Image: picture-alliance/dpa/I. Rechenberg, Technical University Berlin/SUNY College of Environmental Science and Forestry
No frogspawn
This frog (Limnonectes larvaepartus) made the list as a result of its ability to deliver live froglets. Unlike fellow members of Anura family, it doesn't lay eggs. Fertilization takes place inside the female, who gives birth to tadpoles. On this image, the female can be seen on the right.
Image: picture-alliance/dpa/J. A. McGuire/SUNY College of Environmental Science and Forestry
Crop circles in the sea
This fish (Torquigener albomaculosus) builds nests that look like crop circles: round in shape and some two meters high. The male digs a trough using his vibrating anal fins and the rear end of his body.
Image: picture-alliance/dpa/Y. Okata/SUNY College of Environmental Science and Forestry
Christmas tree with a difference
Although this plant (Tillandsia religiosa) has long served as a Christmas decoration in Mexico, scientists have only recently become aware of it. Growing to heights of 1.50 meters, it can be found stuck to the surface of rocks. It blossoms between December and March.
Image: picture-alliance/dpa/R. Bolland/SUNY College of Environmental Science and Forestry
Kind of twiggy
Until recently, researchers had managed to overlook this delicate looking insect. (Phryganistria tamdaoensis) Some 25 cm in length and brown in color, it can easily pass for a stick. But now its identity has been revealed, it has become a favorite research object at the Tam-Dao National Park in northern Vietnam.
Image: picture-alliance/dpa/B. Kneubühler/SUNY College of Environmental Science and Forestry
Striking snail
This snail (Phyllodesmium acanthorhinum) is perhaps one of the most beautiful in the species. It lives in the sea off Japan and measures a modest 17 to 18 mm. Apart from its diminutive size, its red, blue, white and gold coloring make it a sight to behold.
Image: picture-alliance/dpa/R. Bolland/SUNY College of Environmental Science and Forestry
Discovered after extinction
This newly discovered species has been extinct for a long time. The dinosaur known as "Anzu wyliei" is believed to have had a kind of beak, and feathered limbs and tail. But for all its plumage, it is thought to have been unable to fly. Fossils of the animal found in Dakota are some three and a half meters long and weigh in at 300 kg.
Image: Reuters
Mountain corals
To date, around 50 samples of this plant (Balanophora coralliformis) have been found. It has long branches, roots that grow above ground, and is somehow reminiscent of corals. But it only grows on one particular mountain face on the Philippine island of Luzon - at altitudes of between 1,500 and 1,700 meters.
Image: picture-alliance/dpa/P.B. Pelser & J.F. Barcelona/SUNY College of Environmental Science and Forestry
Mysterious creatures of the deep
This little creature looks like a mushroom and has scientists scratching their heads. They can't work out if it is related to jellyfish or corals, or perhaps something else entirely. But they're on the case, and hope to have the answer soon.
Image: picture-alliance/SUNY College of Environmental Science and Forestry/J. Olesen
Motherly love
This bone-house wasp might not look very unusual, but its behavior definitely is. It constructs a small chamber in which to lay its eggs and places a dead spider inside to serve as nutrition for its larvae. In a separate chamber, she collects dead ants. Exactly why, scientists don't know, but one theory suggests it is to deter unwanted visitors.