The basket web spider in its natural form with its unique lobster pot web and silk, which has now proven to be uniquely robust. Photo credit: Professor Mark Elgar, University of Melbourne
An international collaboration has provided the first glimpses of a new type of silk made by the very unusual Australian basket web spider, who uses it to build a lobster pot web that protects its eggs and catches prey.
The basket web spider weaves a silk that is uniquely stiff and so robust that the basket web does not need any help from the surrounding vegetation to maintain its structure.
“As far as we know, no other spider builds such a web,” said Professor Mark Elgar of the School of BioSciences at the University of Melbourne.
“This silk retains its stiffness and makes a pretty exquisite silk basket or deadly ant trap.”
The collaboration between the University of Melbourne and the University of Bayreuth with the Australian Organization for Nuclear Science and Technology should meet with great interest.
Entomologist William J Rainbow discovered the basket spider in 1900 but did not mention the nature of its silk, perhaps because he had only seen drawings of the web and imagined it was more baggy.
The current study just published in Scientific reportsAs the dimensional stability of a remarkable spider food web achieved by the synergistic arrangement of silk fibers, the silk used to build the basket web has been found to resemble the silk that many species of spiders wrap their eggs with to protect them from the elements and enemies .
“Our discovery could provide insights into the development of foraging,” said Professor Elgar. “It is widely believed that silk food webs, including the magnificent ball nets, arose from the habit of making silk to protect egg boxes. Perhaps the basket net is an extension of the protective egg box and a rare contemporary example of an evolutionary ancestral process. ”
The basket spider is only found in Australia. Its basket has a diameter of approx. 11 mm and a depth of 14 mm and cross-linked threads with different diameters. The nature of silk was revealed by the Australian Synchrotron, a national body of the Australian Organization for Nuclear Science and Technology in southeast Melbourne.
Professor Thomas Scheibel from the University of Bayreuth said the stiffness of silk seems to be due to the synergistic arrangement of microfibers and submicron fibers.
“Nature has created a complex structure that at first glance resembles industrially produced composite materials,” said Professor Scheibel, who headed research from Germany.
“However, further investigations have shown that these are chemically different components and that their respective properties together lead to the extreme elasticity and tenacity of the thread, which results in a high degree of robustness. With today’s composite materials, on the other hand, it is mainly the fibers embedded in the matrix that determine the special properties required, such as high stability. ”
While more work needs to be done to understand the molecular details of silk, there is potential interest in a new genetic material that can be made at scale, according to Professor Scheibel.
“The interesting feature is the high level of lateral stiffness as well as the adhesives that could be useful for different types of applications, but it will be some time before that becomes possible.”
Professor Elgar said, “In general, the wickerwork and the properties of its silk underscore the importance of continuing to study obscure, unknown species.
“It is increasingly recognized that solutions to many of the complex challenges and puzzles we face today can be found in biological systems.
“This so-called ‘bioinspiration’ is based on around 3.8 billion years of natural selection that refines biological forms, processes and systems. The possible insights into this diversity of life, about which we still know little, are breathtaking. ”
Reference: October 19, 2020, Scientific reports.
DOI: 10.1038 / s41598-020-74469-z
