Jumping spider mothers feed their spiderlings with milk far into development, according to a new study that could turn the understanding of invertebrate parenting on its head
Animals offer their descendants all sorts of things Possibilities, be it by burping, unfertilized eggs or in extreme cases, their own meat. However, specialized milk-like secretions are mistakenly attributed exclusively to mammals. Other non-mammals and even invertebrates also produce milk-like secretions. The exciting thing about this new study is not just the fact that spiders produce milk, but also how long they make it.
"It raises interesting questions as to why this is happening at all," said Nathan Professor, a professor at Cincinnati University, who was not involved in the study, Gizmodo said. "Why are these spiders behaving like college kids returning home to live with their parents?"
We often think of invertebrates as robot beings that reproduce and eat, and that's it, but that's not it really the case. Spiders take care of their young in several ways – some just guard the eggs, while others wash the food or lay unfertilized "trophic" eggs that feed newly hatched babies. Jumping spiders that deliver milk, however, represent an extreme case of parental care for invertebrates.
The researchers behind the latest study, all from the Chinese Academy of Sciences, knew that Toxeus magnus or "leaping Spiders "bred in nests that consisted of parents and several teenagers. They wondered if the spider offered any lasting parental care and watched some spiders in the nest. Then they noticed that the spiders did not leave the nest until they were 21 days old. During this time, the mother was never seen feeding her, while the young spiders grew larger.
They looked more closely and noticed that the mother spilled liquid from her upper abdomen onto the surface of the nest that ate the spiders. After a week, the spiders sucked the milk directly from the mother. Although they left the nest after 20 days and were able to feed themselves, they still milk for another 18 days. If they were humans, they would be shown in a cable TV program. After the maturity of the spiders, the mother attacked the returned males, while the females were still allowed to prevent inbreeding, according to the study published today in Science.
For those of you who have doubts about the importance of the secretion Then the researchers blocked the mother's mammary gland with whiteout and the spiders died at the age of 10 days. When the mother was removed from the nest after 20 days, she reduced the overall survival of baby spiders and their overall size.
Scientists have previously observed that other non-mammals produce milk-like secretions, such as pigeons, cockroaches and tsetse flies; Ohrwigs also provide their boys with extended care, said Joshua Benoit, also assistant professor at the University of Cincinnati, who was not involved in the study. He was impressed and convinced of the research, but he thought it may be time to rethink who we credit breastfeeding. Invertebrates eventually account for over 95 percent of the Earth's species.
"The production of a milk-like system may have been more common in invertebrate systems than in vertebrates," Benoit said.
The study has its limits. It is unclear whether jumping spiders in the wild – not confined to a laboratory enclosure like this one – would return to their mother after 20 days, Benoit said. And Morehouse found that it does not really explain why these spiders breastfeed so long and why other spiders do not produce milk. The authors of the study rejected Gizmodo's request for comment.
The work recalls that mammals are not the only animals looking after their young, and others do so in a way that should be appreciated. Morehouse said it was time to look for more examples of milk production in invertebrates. He said, "The takeaway message to me means that this study pervades the peculiarities of mammals."