My Biodiversity: Causes and Conservation class required me to write a paper on something involving conservation that was controversial in some way.
Of course, I had to pick scorpions.
I just finished it, it's due in 7.5 hours, but I'm going to go take a nap. I still need to throw in some references.
Ask someone what they think of scorpions, and odds are good you won’t get a positive response (especially if that someone lives where these arachnids are commonplace). Watch any movie that has scorpions in it, and you’ll encounter a similar negative image. Whether it be harmless Pandinus imperator venom nearly killing The Rock in The Scorpion King, a poster in a French AIDS awareness campaign frightening people into using condoms, or Bear Grylls chowing down on one on the Discovery Channel, public perception of scorpions is not a pleasant one. This negative image that people are presented with so readily contributes to the idea that all scorpions carry deadly venom, despite the fact that there are less than 30 dangerous species out of the roughly 2000 that have been described (cite).
Given this, it would not be surprising if raising the suggestion of scorpion conservation would elicit a response where one’s sanity is called into question.
In reality, scorpions are a (mostly) harmless group of arachnids that are more diverse than the average person is probably aware. They are distributed nearly globally south of 49 degrees of north latitude (with the notable exception of Antarctica) and inhabit a wide range of environments; from temperate forests (such as Oregon’s own Uroctonus mordax), to tropical jungles, to the hottest deserts. While it is true that many scorpions are particularly well-adapted to a hot, dry climate, this is by no means the only place one finds them. In fact, the most commonly seen scorpion in movies and television that is often shown trekking through an arid landscape is native to jungles and savannah from West Africa.
The idea that all scorpions are natural-born killers is an undeserved reputation, but is understandable from an anthropological standpoint – early civilizations that arose in the Middle East were in an area of the world that contains the majority of potentially deadly scorpion species. This would have factored heavily into these cultures and as such be passed down to future generations. Today such responses have been exploited for entertainment purposes and contribute to one thinking that any scorpion has the potential to kill. However, the danger of these arthropods is greatly exaggerated. Even a sting from one of the handful of dangerous species is unlikely to prove fatal to a healthy adult human. Centruroides sculpturatus, the only medically significant species to be found in the US, has not caused a single human death since 1968. (cite)
Even knowing this many may be hesitant think of scorpions positively. In the author’s experience of demonstrating the handling of live specimens, the most common question is “why doesn’t it sting you?” Harmlessness aside, the fable of The Scorpion and the Frog persists. A great number of species will sooner play dead than sting when. Venom is metabolically costly to manufacture and a scorpion won’t let it go to waste. When tucking in legs and remaining motionless fails to deter a threat, the usual response is to turn and run. Firsthand experience on the part of the author shows that many scorpions will “hold their ground” and go into a defensive posture and prominently display their pinchers and stinger when cornered (such as in a cage), but upon removal will simply wander about looking for somewhere to hide.
(As an aside, the only stings the author has received were nearly dry “warning shots” that contained little venom and resulted in almost no pain.)
It’s possible that someone reading thus far may have decided that scorpions don’t entirely deserve the bad reputation they have – but why should anyone care about conservation of these interesting-looking but otherwise unremarkable bugs?
How about curing cancer?
There have been numerous studies involving a small peptide structure called chlorotoxin, which is isolated from the venom of Leiurus quinquestriatus. These studies have shown that it binds to a certain membrane protein that is only found in significant numbers on glioma cells – cells in a particularly debilitating form of brain cancer. In binding to these membrane proteins, chlorotoxin can have two major applications. The first is that it can be tagged with a fluorescent protein prior to injection into a patient. This means that when present in high enough numbers, the protein will fluoresce green under ultraviolet light. To a surgeon operating on a tumor, this means a visual flag of where that tumor is. The second application is similar, but instead of a fluorescent tag, one could attach a radioactive tag. Upon binding to a tumor chlorotoxin would essentially be delivering radiation therapy only to the cells that are actually cancerous.
Another reason people should care about conserving scorpions, though less dramatic than the implications of chlorotoxin, is that scorpions are a vital component of their ecosystems – which, as stated earlier, encompass a large area of the planet we inhabit.
In their native ranges, scorpions are indicator species and are thus useful when studying biodiversity in an area. There are several reasons for this.
The first reason is their place in the food chain. Among arthropod communities, scorpions are the top predators. An example of this is Scorpio maurus annually eating 11% of the Israeli isopod population (Sachack & Brand 1983), or Australia’s Urodacus yaschenkoi consuming 7 pounds of invertebrates per acre (Shorthouse & Marples 1982). California’s native Smeringurus mesaensis has even been observed to eat over 100 different varieties of arthropod as its prey. Scorpions are also important in an environment’s food chain in that they are preyed upon by a variety animals, such as other predatory arthropods or some vertebrates.
The second reason scorpions can be utilized as an indicator species is their requirement for specific habitats – the most important aspect being soil type. A large number of species burrow, or at least scrape out a shallow depression underneath some form of shelter, and many of these burrowers are specialists as to what sort of substrate they will inhabit. An area showing greater diversity in soil types is likely to show a greater diversity in scorpion fauna. (cite)
The third major reason that studying scorpions can allow for reflection of an ecosystem’s health is closely related to the first two – compared to other arthropods, they have a very slow generational process. Scorpions, like many invertebrates, have a seasonal mating schedule, but they differ in that a female’s gestation may range from four months to well over a year, depending on the species. The brood may range from only a few individuals to over eighty, but rarely surpasses 100. These young then take at least two years to reach maturity in almost all species, with many taking considerably longer. These three characteristics of scorpion reproduction and growth make them very slow to rebound after something drops their population – compare this to other arthropods that may complete a full generation in under a year with several hundred offspring resulting from each mating.
All three of these characteristics of scorpions intimately tie into each other. A scorpion is an important member of its ecosystem’s predator-prey network, it requires a suitable microhabitat to live in, and is slow to replenish its population after a drop-off. These make scorpions not only useful indicators for research, but key to the biodiversity of a region. If something were to kill off a large number of scorpions in an area, their population would be unable to bounce back, their prey items would have a population explosion, and their predators would die off. Something that could kill off or displace a large number of scorpions could be anything from habitat loss (because of their specific microhabitat requirements for survival) to pesticides killing their preferred prey. The latter example may result in increased cannibalism which would drop their numbers even faster.
These possibilities are somewhat extreme, but they illustrate that scorpions are essential to the health and biodiversity of the areas they inhabit.
Unfortunately there are situations threatening scorpions that are not so hypothetical. The two best examples are the pet and souvenir trades. In the pet trade, the most commonly encountered species is Pandinus imperator, the large black “emperor” scorpion found in almost any pet store in the US. This species is exported from West Africa in numbers exceeding 100 thousand annually (Sissom & Hendrixson 2005) to the point where it is now listed on the Convention on International Trade in Endangered Species (CITES). CITES currently lists this scorpion in Appendix II, which according to their website means that it is “not necessarily now threatened with extinction but [it] may become so unless trade is closely controlled.”
The souvenir trade is more difficult to find numbers for simply because it involves no protected species. Many of the glow-in-the dark Lucite trinkets with a scorpion inside are Mesobuthus martensii, a species found in and exported from China. The cheap mass-production of them alone is enough to suggest this is happening in high enough numbers to cause concern. There are also the novelty liquor bottles from Southeast Asia containing preserved members of the Heterometrus genus. Even in the US, Hotlix is a company that sells a variety of arthropod-containing candies, including a line of suckers with a scorpion in the center. Even though the species is probably Centruroides vittatus, the most commonly-found species in the US, a high enough candy production could negatively impact this species’ wild populations.
Besides the economic interactions between humans and scorpions that are hurting their numbers, there is also the impact of human expansion. Perhaps the best example is that of the American Southwest. Those species that can only construct their burrows in specific soil types are simply killed off by suburban development in the rapidly expanding southwest and as such are never noticed by the new inhabitants – however, bark scorpions have no such requirements and just stay behind, living in peoples’ yards and homes. This further contributes to the strained relationships between humans and scorpions mentioned earlier.
This may make for a bleak outlook for efforts to promote the conservation of scorpions, despite how critical they are to the ecosystems which they are part of. However, there is some hope. A major leap forward would be accomplished by providing formal protection for those species that are most threatened by human activities. To collectors, it may seem as though there is a limitless supply of scorpions where they are found, but if changes are not made that will not continue to be the case. Besides restricting the number that can be caught, formal protection would also prevent scorpions from being mistreated in film, a situation that furthers the negative impression people have of them.
As an example of the potential effects of protection, consider what might happen if exports of P. imperator were strongly restricted. With fewer specimens coming into pet stores they would cost more once they arrived. This would encourage hobbyists to breed the specimens already in captivity, which would eventually have a feedback effect on the demand for wild-caught specimens, further reducing the number imported (i.e., if more are bred in captivity, fewer would be purchased at pet stores). Protection is important for another reason, as well: chlorotoxin, the cancer-binding venom protein mentioned earlier, can also be isolated from M. martensii venom: the same species being exported en masse in the form of glowing trinkets from China.
Another step forward would be for the sources of research dollars to allocate more money to studying these arachnids. If academia can prove the ecological importance of scorpions to the general public (especially in the context of maintaining providers of ecological services, such as parks), it may move another step forward in improving public opinion. Along these lines, public education in areas where humans and scorpions overlap could also help. The average Arizonan might not be so fed up with the native bark scorpions if information were provided on scorpion-proofing his or her home.
One final idea is to promote captive-breeding within the scorpion-keeping hobby. As stated earlier, captive-breeding can work to reduce the demand for wild-caught specimens. Fortunately, this step is already well underway. There is a healthy community of scorpion hobbyists throughout the internet (the author is a member of three forums catering to invertebrate hobbies, one of which is designed with scorpion-keepers in mind) and many of these individuals are well aware of the importance of breeding their collections in captivity. The only drawback to this is that one of the more popular species, Hadrurus arizonensis from Arizona and a few neighboring states, is notoriously difficult to raise from an early age. Despite this, some have had success with this species and are passing on their knowledge to others.
_________________
If your emperor scorpion stops eating, don't panic. | My
reviews | My Bug Pictures | My blog
Be nice -- you were a noob once, too
"Never ask an engineer to explain something, because he will."
that must have taken ages! glad your sticking up for the scorps! hope this changes some peopes minds!
mike! 
