It’s common to tell apart species of other groups like millipedes and spiders. These are the first scorpions to be distinguished by their male reproductive anatomy.
The Australian Journal of Zoology has published our findings,. This suggests that there are many more scorpions in Australia than was previously thought.
A popular and widespread group
Most Australians consider scorpions to be exotic desert creatures. They are widespread, from the salt lakes of central Australia to the ancient rain forests of Tasmania.
Our estimates (based on unpublished data from DNA sequences we have access to) indicate that less than 10 percent of Australia’s scorpions have been scientifically named or described. To describe them, you must document the new species scientifically and give it a scientific name that is unique to its species. This should be done in accordance with the International Code of Zoological Nomenclature.
The scorpion genus Urodacus is endemic to mainland Australia and represents one of the largest radiations (increases in diversity) of scorpion species on the continent. Most Urodacus species live in deep spiraling burrows, enabling them to survive in arid ecosystems. In some habitats, these scorpions are a significant part of the ecosystem and comprise much of its biomass.
Despite their reclusive habits, Urodacus are popular exotic “pets” and are among the most popular invertebrates offered by online stores in Australia. There’s also a large community of scorpion enthusiasts.
A male of one of the new species was recently collected from Toweranna in the Pilbara region of Western Australia, within the known area of occurrence of Urodacus lunatus. Huon L Clark
Trading of scorpions is dependent on an unknown level of harvesting from natural populations. Some Urodacus species are known to live for 15-20 years, but in captivity, their longevity is usually less than a year.
With minimal knowledge about the diversity and distributions of Australian scorpions, the potential for serious impacts on their conservation is high. Traded scorpion species are often unnamed, and some may also live in very small areas.
For example, the two new species we described, Urodacus uncinus and Urodacus lunatus, are restricted to creeks and drainage lines, with a known area of as little as 50 square kilometers. Such small distributions make species particularly vulnerable to habitat loss, which is a growing threat in Australia.
Surprisingly, there is no regulation for scorpion ownership in most Australian states, although you need a permit to keep them as pets in the Northern Territory and Queensland. Collecting them from the wild is only regulated in conservation areas.
An example of the type of habitat where the newly described species were collected. Huon L Clark
Read more: Buying bugs and beetles, or shopping for scorpions and snails? Australia’s pet trade includes hundreds of spineless species.
We don’t know enough about our scorpions.
The two new species we just described are large (more than 7cm long) yellow scorpions. Males of both species have a striking enlargement in the tip of their “tails,” with a swollen venom gland and a sting that is more strongly curved than in any other known species of the genus.
The task of fully documenting and understanding the diversity of Australian scorpions is colossal. Approximately 3,000 scorpion species are known worldwide, but in Australia, only 47 species are currently described and named. Based on our estimates, there could be at least 500 scorpion species here.
Only 13 new Australian scorpion species have been described in the last 45 years. At this rate, many are likely to become extinct before they are even named.
Further research on Australian scorpions will also reveal more of these animals’ incredible biology. One example is their curious reproduction. Scorpion mating rituals include a dance during which males of some species even sting the females as part of the courtship.
Sperm transfer occurs via what could be described as a “detachable penis” placed on the ground by the male. During mating, part of this organ breaks off in the female reproductive tract and functions as a “mating plug” that prevents the female from remating until the babies from the last mating are born.
Burrowing scorpions give birth to live young that are gestated for up to 18 months within an organ, somewhat like a uterus. After birth, mother scorpions carry their babies on their backs until they disperse to live a largely solitary life.
Undiscovered secrets
These fascinating behaviors are only a small portion of the natural history of scorpions discovered to date, and they are likely to harbor many more undiscovered secrets as yet.
Next, nothing is known about Australian scorpions, which is surprising given their diversity and ecological importance. More research on Australia’s scorpions is urgently needed to help recognize and protect threatened species and their habitats.
Expanding our knowledge about native scorpions would also help with the regulation of wild collections and allow captive breeding to develop further more responsible pet ownership as a force for conservation rather than a risk.
