International research cooperationThe Most Poisonous Spider in the World includes 3 Different Species

13 January 2025, by Newsroom editorial office

Photo: University of Hamburg/Esfandiari

The research team from the University of Hamburg and the Leibniz Institute: Stephanie Frances Loria, Dr. Danilo Harms, and Svea-Celina Frank (from left)

The Sydney funnel web spider is one of the most poisonous spiders in the world. One international research team, which includes the Leibniz Institute for the Analysis of Biodiversity Change and the University of Hamburg, has now found out that this spider is a complex of 3 species that includes a previously unknown type. This is important knowledge for the manufacturing of antidotes.

The Sydney funnel web spider lives surrounding region of the Australian city of Sydney and is one of the few spiders in the world whose bite can be very dangerous to adult humans. Although significant optical differences among the animals have been observed, researchers have assigned them the common name Atrax robustus.

A research team headed by Dr. Danilo Harms, spider researcher at the the Leibniz Institute for the Analysis of Biodiversity Change, and Dr. Bruno Buzatto from Flinders University in Adelaide (Australia), has now discovered that the spider species is actually a complex of several species that differ genetically and morphologically.

Combination of different investigative methods

“On the one hand, we collected DNA samples of animals,” said Harms. The morphological analyses, meaning the analysis of external features, were crucial, Harms continued. For this, the team looked at animals captured recently and specimens from collections. “In the scientific collections of the Australian Museum, Sydney and in our collections in Hamburg, we have animals from the entire area they inhabit, some of which were collected centuries ago,” said Harms. The arachneological collection in Hamburg alone, he said, has several hundred specimens of the funnel web spider, creating a very detailed portrait.

The combination of genetic and morphological data revealed that the “real” Sydney funnel web spider (Atrax robustus) is found primarily in greater Syney and on the Central Coast. A second species that the researchers are calling the southern Sydney funnel web spider ((Atrax montanus) lives further south and west of Sydney. This species has already been named once but was not previously accepted as its own species. The third and significantly larger species is called the Newcastle funnel web (Atrax christenseni) and described in the current article in BMC Ecology and Evolution. Accordingly, it hails from Newcastle.

Important findings for toxicology research

These research findings are not only an important contribution to taxonomy, or the classification of organisms, but also relevant for applied science, for example, toxicology. To date, fatalities from spider bites have been extremely rare. Between 1927 and 1979, there were 13 fatalities that were most likely the result of Sydney funnel web spider poisoning.

The poison of the male spider is roughly 6 times more poisonous than that of the female.

Biochemical studies have shown that the poison of the male is about 6 times more toxic than that of the female spider. In the early 1980s, an antidote was made available and since then, there have been no further fatalities.

“Studies have shown that spider poison is species-specific, although different spider species produce different poison profiles,” explained Harms. For the funnel web spider, he said, there had not yet been any distinction between the species. “It will be interesting to see comparative studies of all 3 species in greater Sydney in the future. Even if there is an effective antidote, taking species-specific differences into account can be valuable for producing antidotes for funnel web spider bites.”

Large-scale cooperation project

Researchers from the Leibniz Institute, the University of Hamburg, Flinders University, the Australian Museum, Sydney, and the University of Sydney took part in describing the 3 new species. Svea-Celina Frank, a bachelor’s student at the University of Hamburg, also took part. “The research project was one of the greatest adventures of my life. Tracking the most poisonous spiders in the world in the forests of Australia gives you a very different view of nature,” said Frank. The group’s research was funded by National Geographic and the Australian Geographic Society.