Her mother treats her for a few weeks with milk that has four times the cow's protein. Yet this mother is not a mammal. It's a bouncy spider with eight legs and a taste for the fruit of the fly.
We have named the mammals themselves after the mammary glands. Still, other animals, from tsetse to pigeons, exclude their own milk versions for their children. Newly Discovered Nursing in Toxeus magnus may be the most mammalian of all, suggests a research team from China in November Science.
Biologists have recognized T. magnus as a species since 1933, but the little spider's maternal habit was easily omitted. Spiders hunt animals like fruit flies and retreat into a small nest, perhaps attached to a leaf to raise a family.
Study co-author Zhanqi Chen of the Chinese Academy of Sciences in Menglunzhen, who studies spider behavior, noticed several T. magnus share the nest in 2012 and wonder if the species has some extended parental care. It was another five years before he saw the nursing behavior when in 2017 the mummy's arm was able to see the spider web.
WITH T. magnus the female under the microscope, a soft toe on the underside of the abdomen, pushes a tiny bead of white fluid from the folds called the epigastric groove, scientists say. For the first week or so after hatching the spider eggs, Mom leaves the milk drops around the nest to crack the young dots. Then the nurses turn more mammals and the little ones cling to their mother's body.
<Img src = "data: image / png, Base64, iVBORw0KGgoAAAANSUhEUgAAAAIAAAABCAIAAAB7QOjdAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAAyZpVFh0WE1MOmNvbS5hZG9iZS54bXAAAAAAADw / eHBhY2tldCBiZWdpbj0i77u / IiBpZD0iVzVNME1wQ2VoaUh6cmVTek5UY3prYzlkIj8 + 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 UQ9InhtcC5paWQ6 RDQ5NTg3OTZFNzAwMTFFNzhERUM5QzdDODEzNjdDMTEiIHN0UmVmOmRvY3VtZW50SUQ9InhtcC5kaWQ6RDQ5NTg3OTdFNzAwMTFFNzhERUM5QzdDODEzNjdDMTEiLz4gPC9yZGY6RGVzY3JpcHRpb24 + IDwvcmRmOlJERj4gPC94OnhtcG1ldGE IDW + / + eHBhY2tldCBlbmQ9InIiPz5Sc9lyAAAAEklEQVR42mJ89 4dAwMDQIABAA4AAsyHwrk2AAAAAElFTkSuQmCC "echo data =" https://www.sciencenews.org/sites/default/files/images/112918_SM_jumping-spider_inline_370.jpg "alt =" jumping spider "class =" Caption " style = "float: right; width: 370px; height: 284px; "title ="TRANSPORTED MILK MAKER Woman Toxeus magnus the spider (shown) will feed her young on milk for more than a month. ~ ~ Z. Chen et al., Science 2018 "/>
How can the songwriter be entertained by the evolutionary physiologist Wendy Hood of Auburn University in Alabama, who is studying lactation. In platypus and echidna, also known as barbed ant, women do not have nipples. Infants get milk coming from the mammary glands to the surface of the skin "much like sweat glands," he says. In most mammals, however, the child rather than licking, releasing milk into the mouth.
Nutrition packed in spider milk has basic components known in mammalian milk: about 2 milligrams of sugar per milliliter of milk, 5 milligrams of fat and 124 milligrams of protein. That's all that spiderlings get in the first 20 days of their life, researchers report. In nests in the laboratory, mothers occasionally hunted fruit flies provided by scientists, but they never came home from prey to feed their offspring.
After 20 days, the spiders started to grow on their own, but also treated for almost three weeks. With this combined diet, 76 percent of the youngsters survived in laboratory nests. But when the scientists closed an epicureal mum with a correction liquid, once the spiders hatched, they died about in 10 days.
The scientists were also wondering if milk had a significant impact when the youngsters started to hunt. Oh yes. The loss of these older spiders by firming the mum's lattice on day 20 has reduced the survival rate to about 50 percent, researchers say.
With such extensive care from mother, T. magnus spiders eventually share the nest for an unusually long time in the predominantly lonely, ferocious world of spiders, says behavioral arachnologist Linda Rayor of Cornell University. Only about 120 of nearly 48,000 known spider species are known to tolerate society, including siblings, for more than three weeks. And only about 30 of them live a lifetime of social life. So an example of spiders who share a nest for 40 days, says Rayor, is "a big problem."
Time of food female Toxeus magnus Spiders who come from tropical and subtropical regions of Asia produce milk that feeds their youngsters for weeks, even after the spiders have started hunting themselves. Here are 1-week-old juvenile nurses in the area of her mother's belly where milk is available.