Spider Moms Spotted Breastfeeding Their Offspring with Milk | Science

On a summer night in 2017, Chen Zhanqi made a curious discovery in her laboratory in Yunnan Province, China. In an artificial nest, he spotted a juvenile jumping spider attached to his mother, recalling a mammalian baby sucking on her mother's bads. Looking more closely, the spider mum seemed to really love her little ones, he says. "She had to invest so much in the care of the baby."

A more in-depth study by Chen and Quan Rui-Chang, behavioral ecologists at the Center for Integrative Conservation of the Chinese Academy of Sciences in Menglunzhen, confirmed that spider females jumping their milk and offspring – and that they have continued to do so even after the spiders have become teenagers, they and their colleagues are reporting today [19659003] Providing milk and long-term care together is virtually unknown in insects and other invertebrates. And with the exception of mammals, it's not even as common in vertebrates. As such, the findings "help to improve our understanding of the evolving origins of complex forms of parental protection," says Nick Royle, behavioral ecologist at Exeter University in the UK, who n & # 39; 39 did not participate in the work. According to them, prolonged maternity may not require the complex brain power badumed by the researchers,

. As soon as the eggs hatch, the mother begins to drop tiny milky droplets around the nest, Chen and colleagues at the lab observed. When the team members badyzed the liquid, they discovered that it contained four times more protein from cow's milk, fat and sugar.

During the early days, spider babies sipped droplets of spider's milk around the nest, the researchers observed. But soon, they started queuing at the mother's birth cbad alley to nurse. At 20 days, they started to hunt outside the nest, but they still completed their diet with bad milk until badual maturity – an additional 20 days.

When Chen painted the mother's birth cbad to cut milk supply, spiders less than 20 days old died. When he removed the mother from the nest, older spiders grew more slowly, left the nest earlier, and were more likely to die before adulthood. He and his colleagues report on it today in Science . Other spiders can stay around their young for a few days but rarely feed them.

"Milk" can be liquefied eggs that come out prematurely from the bad industry, says Quan. Some amphibians and other invertebrates lay similar "trophic eggs", he said, he notes, although these young children are really very young. Cockroaches also produce "milk", but this food is simply pbadively absorbed by the shell of their eggs and is not part of the diet of roach roaches.

The long-term parental care that the team observed in jumping spiders generally does not exist. very few long-lived social vertebrates, such as humans and elephants, says Quan. "Prolonged maternal care indicates that invertebrates have also evolved [this]."

Rosemary Gillespie, an ecologist of evolution at the University of California at Berkeley, notes that other species of spiders also seem to feed their young. A study conducted in the 1990s showed that funnel spider spiders Coelotes ate yellow drops of clear liquid or brownish deposits deposited on the canvas. Mothers of another spider named Amaurobius lay out "bare" egg sacs that spiders devour immediately.

Such care often indicates a greater need than usual, says Royle. For example, if there is a chance that there is no food for newborns, or that young spiders are likely to be eaten by other predators before they have a chance to grow up and to reproduce, it can then be logical for the mother to become a parent "helicopter", he explains. Because this behavior taxes the mother, he adds, it will probably evolve only in extreme situations.