why is hottentotta tamulus so deadly?

[Johnn]

I have several theories of why hottentotta tamulus is considered by many to be the most deadly scorpion in the world. I was just looking for input to see what others thought and if anyone could bring new information to the table. So anyways, h. tamulus has mortality rates ranging from 8 to nearly forty percent and averaged out to about 30 percent in the 60s and 70s before the invention of the blood pressure medication Prozasin. it seems its neurotoxin tamapin attacks mostly the respiratory system and the cardiovascular systems. so anyways, the first reason it's so deadly is that India has a very high child to adult ratio. secondly, it injects a large amount of venom (up to 1.5 mg compared to .5 mg for androctonus australis and mauretanicus). also, antivenom has little effect on h. tamulus envenomations which could possibly be an indicator that the human body isn't as well equipped to create antibodies to neutralize the venom? dunno about that one. i think they use horses to make antivenom but if an effective antivenom can't be created, maybe its an indication that a horse cant properly fight the venom off, wgich may mean a human couldnt either. also, the protein content in h. tamulus venom is a whopping 70 percent (compared to 14.8 percent with a. crassicauda). however i will say that these particular a. crassicauda had an ld50 of 1.7 mg/kg vs an ld50 of .4 mg/kg sc that has been recorded in others. so this might not be the best example of a. crassicauda protein contentthis is my theory of why the h. tamulus is so deadly despite it's ld50 being higher than a lot of other highly venomous scorpions (which doesnt necessarily predict how toxic it will be to human beings). if anyone has any more info or any other theories or info on h. tamulus's venom, please feel free to share. thank you

 

[Outpost31Survivor]

Comparing species through their intra-specific variable venom compositions and their unreliable LD50 results is a very difficult task (*see the quote below) is like looking through a glass darkly. But I agree the high mortality rate of H. tamulus is definitely related to the high child to adult ratio, lack of clinics and poorly trained staff in treating severe scorpion envenomations in rural areas particularly during the periods that recorded high mortality rates from Hottentotta tamulus stings, and due of course to the synanthropic nature of Hottentotta tamulus. But that is not all the contributing factors.

In India, morbidity and mortality due to scorpion stings frequently occur in western Maharashtra, Saurashtra, Kerala, Andhra Pradesh, Tamil Nadu, and Karnataka. A case study involving 141 children admitted to Government Raja Mirasdhar Hospital (Thanjavur, southern India) with a real Indian red scorpion sting, demonstrated that children between 1–3 and 7–12 years of age exhibited the following: most adverse effects to envenomation. Eight patients displayed priapism and five patients up to 6 years. One patient older than 6 years exhibited pulmonary edema, a fatal and life-threatening sting effect (Yuvaraja et al., 2019). Records from a tertiary care and teaching hospital in southern India showed that 50 patients experiencing Indian red scorpion sting demonstrated dyspnoea (n = 13, 26%), chest pain (n = 9, 18%), vomiting (n = 6, 12%), sweating (n = 5, 10%), nausea (n = 3, 6%), priapism (n = 7, 14%) and piloerection (n = 6, 12%) (Madhavan, 2015).


An epidemiological study conducted in Mahad (200 km south of Mumbai, Western India) from 1984 to 1995 also showed that children <16 years tend to respond more poorly to Indian red scorpion sting (Bawaskar and Bawaskar, 1998); out of the 293 patients, six deaths were reported before hospital arrival. Patients were further divided into three broad groups based on the clinical symptoms- i) 111 (38%) patients exhibited hypertension within 1–10 h (mean 3.5 h), ii) 87 (30%) patients with tachycardia reported within 1–24 h (mean 6.7 h), and iii) 72 (24.5%) patients with pulmonary oedema reported within 6–24 h (mean 8 h) post scorpion sting (Bawaskar and Bawaskar, 1996; Bawaskar and Bawaskar, 1998).


A 14 year old healthy male from the Babaganj region of Northern India developed cardiac and gastrointestinal complications following an Indian red scorpion sting on the right big toe (Agrawal et al., 2015). Twenty-three Indian red scorpion stings have been documented in three localities of Jaffna, Sri Lanka, consisting of 13 (57%) males and 10 (43%) females. While the mean age was 30 years (Kularatne et al., 2015), 5 (22%) cases were children below 12. Upon admission to the hospital, all patients had evidence of either local or systemic manifestations envenoming (Kularatne et al., 2015; Ratnayake et al., 2016). Thirty-three scorpion stings were reported at Rims Teaching Hospital, Raichur, Karnataka, India, from 2009 to 2014, of which 22 were from the Indian black scorpion and 11 from the Indian red scorpion. The patients exhibited bradycardia, drowsiness, cutaneous manifestations, hypotension, and hypertension (Rajashekhar and Mudgal, 2017).

Diversity of Indian Red Scorpion Venom

Geographical variation in sting severity has been reported in India (Reddy, 2013; Suranse et al., 2019) (Figure 2) and is a likely consequence of variation in population genetic structure, which drives phenotypic differences in venom composition (Newton et al., 2007). Several populations of Indian red scorpions collected from eight locations in Maharashtra (Bhate plateau, Sangameshwar, Jejuri, Shindavane, Pashan, Alandi, Kalyan, and Jalna) exhibited moderate genetic variation, with regression analysis suggesting that the genetic distance of subspecies increases by 0.006% (95%CI: 0.003–0.010%) per Kilometre of geographical separation (Suranse et al., 2017). It has also been suggested that genetic structure correlates to climatic differences in precipitation, specifically high, moderate, and low rainfall areas (Suranse et al., 2017), associated with differences in venom phenotype. For example, significant variation in the expression of venom peptides was observed between Indian red scorpions collected from the Konkan region of Maharashtra and the semi arid Deccan plateau (Newton et al., 2007). In addition, anecdotal reports suggest that stings from Indian red scorpions of the Konkan region on the western side of the Western Ghats are more severe than stings from populations on the eastern side of the Western Ghats. These differences are likely due to variations in venom peptide composition between the two populations (Newton et al., 2007). While other factors may contribute to the pathophysiology of the sting, these have not been addressed in the literature (Bawaskar and Bawaskar, 1992; Kankonkar et al., 1998; Murthy and Zare, 1998; Newton et al., 2007). Intra-specific venom variation has also been demonstrated between Indian red scorpions from Western India (Ratnagiri, Chiplun, and Ahmednagar) and Southern India Chennai by sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE) (Badhe et al., 2006). Mice injected with equal concentrations of Indian red scorpion venom obtained from the above geographical regions showed significant variation in their blood sodium levels (Badhe et al., 2007). While in-depth analyses of Indian red scorpion venoms from different areas of the Indian sub-continent are currently lacking, this data would help uncover the geographical impact on venom composition. Although venom variation has been shown to result in differences in sting severity and symptoms for scorpions from different regions of the world (Abroug et al., 2020), a detailed description of this topic is beyond the scope of the current review.

Frontiers | Biochemical and Proteomic Characterization, and Pharmacological Insights of Indian Red Scorpion Venom Toxins

The Indian red scorpion (Mesobuthus tamulus) is one of the world’s deadliest scorpions, with stings representing a life-threatening medical emergency. This s...

www.frontiersin.org

 

[Supreme]

I'd also like to know the amount of venom injected for each type of sting as well, especially which serrulatus vs tamulus are more dangerous in 1 hit. Of course serrulatus has a stronger LD50 but how much venom is injected? want to know

 

[Outpost31Survivor]

I'd also like to know the amount of venom injected for each type of sting as well, especially which serrulatus vs tamulus are more dangerous in 1 hit. Of course serrulatus has a stronger LD50 but how much venom is injected? want to know

The picture really is too incomplete but T. serrulatus has an estimated mortality rate of 1%-2% among children and the elderly. Hottentotta tamulus has estimated mortality rate of less than 4% due to prozasin and greater spending on health care that has improved medical training, education, and better equipped clinics.


Acute toxicity tests and their LD50 results can be misleading. Plus, mice aren't human, humans aren't mice. You are testing the toxicity of two different species of animals with scorpion venom that is armed with toxins that have proven to have target-specificity across various invertebrates and vertebrates with varying lethal efficacy.

 

[Johnn]

I'd also like to know the amount of venom injected for each type of sting as well, especially which serrulatus vs tamulus are more dangerous in 1 hit. Of course serrulatus has a stronger LD50 but how much venom is injected? want to know

yeah the t. serrulatus is i think .43 mg/kg and h. tamulus really varies. but i found this formula for finding ld50s for humans compared to animals. it wouldnt work in every case with every scorpion and should be taken with a grain of salt but heres the link

Determination of median effective dose (ED50) of scorpion antivenom against scorpion envenomation using a newly developed formula - PMC

About 50 species of scorpions cause fatal scorpionism worldwide. Most of these are members of the Buthidae family, and include, among others, Mesobuthus eupeus, Androctonus crassicauda, Leiurus abdullahbayrami, Leiurus quinquestriatus, Tityus ...

www.ncbi.nlm.nih.gov

The picture really is too incomplete but T. serrulatus has an estimated mortality rate of 1%-2% among children and the elderly. Hottentotta tamulus has estimated mortality rate of less than 4% due to prozasin and greater spending on health care that has improved medical training, education, and better equipped clinics.


Acute toxicity tests and their LD50 results can be misleading. Plus, mice aren't human, humans aren't mice. You are testing the toxicity of two different species of animals with scorpion venom that is armed with toxins that have proven to have target-specificity across various invertebrates and vertebrates with varying lethal efficacy.

also theres the hemiscorpius lepturus. its cytotoxic venom is enough to cause up to a 9 percent mortality rate but it only has enough venom (altogether, not just with one sting) to kill just under 2 (i'm assuming 20 gram) mice. just goes to show how much venom's effects vary from species to species

I'd also like to know the amount of venom injected for each type of sting as well, especially which serrulatus vs tamulus are more dangerous in 1 hit. Of course serrulatus has a stronger LD50 but how much venom is injected? want to know

and to answer your question, I duno how much venom t. serrulatus injects but h. tamulus injects up to 1.5 mg and I don't know but id be willing to bet that the h. tamulus has a stronger venom towards humans even when not considering the difference in volume, even though its not as deadly towards mice. that's just my guess though. I could be wrong. but in any case, sting for sting the h. tamulus is definitely much worse than the t. serrulatus. the t. serrulatus isn't all that deadly when compared to the more venomous androctonus species. id guess it's venom load with a single sting is well under 500 ug

 

[Supreme]

Thanks for the great insight. I read every line Although the language translation may not be very stable The more I like Tamulus. and I immediately bought it.

 

[Outpost31Survivor]

also theres the hemiscorpius lepturus. its cytotoxic venom is enough to cause up to a 9 percent mortality rate but it only has enough venom (altogether, not just with one sting) to kill just under 2 (i'm assuming 20 gram) mice. just goes to show how much venom's effects vary from species to species

Yes, due to intra-specific variation of toxin composition in scorpion venom both within and without geographically based populations the picture for any given species is incomplete with many pieces of the puzzle missing and probably will remain so indefinitely. As you know the inclusion and exclusion of these toxins determine the level of lethal potency in human envenomations.

 

[Johnn]

Thanks for the great insight. I read every line Although the language translation may not be very stable The more I like Tamulus. and I immediately bought it.

no problem. so you said you bought a h. tamulus?

 

[Supreme]

no problem. so you said you bought a h. tamulus?

Yes, after reading it I like it and it's easy to find and not expensive in Thailand.

 

[The Snark]

One aspect I'm not seeing thoroughly tested is the venom delivery mechanism and quantity. This seems odd going by the fact scorpions have a very functional and accurate sting ability. That is if something presses down on it, it almost certainly will hit with the stinger. Along the lines of real, present and mechanically near perfect.
Now couple that to an extensive study of how much if any venom is delivered with each sting. A chart could be made that shows each species from most to least and dry stings. That chart should be held up in comparison to known common highly pathogenic effects such as cardiac arrhythmia where mechanisms other than pain response triggered shock conditions don't weigh in as heavily.
IE Species, + venom delivery in predictable quantities, + non maskable physiological manifestations = True venom potency.

 

[Johnn]

Yes, after reading it I like it and it's easy to find and not expensive in Thailand.

do you know if you have a male or female? i have a female and wanna breed it but dont have a male. but my female wont reach sexual maturity for at least a few months. and do you know what instar yours is? also any pictues?

 

[Johnn]

Yes, due to intra-specific variation of toxin composition in scorpion venom both within and without geographically based populations the picture for any given species is incomplete with many pieces of the puzzle missing and probably will remain so indefinitely. As you know the inclusion and exclusion of these toxins determine the level of lethal potency in human envenomations.

Apparently H. Tamulus has a 1-5 percent mortality rate in adults(or altogether, not sure) and 15 percent in children. i guess this is after prozasin?

https://core.ac.uk/download/154424202.pdf

 

[Outpost31Survivor]

Apparently H. Tamulus has a 1-5 percent mortality rate in adults(or altogether, not sure) and 15 percent in children. i guess this is after prozasin?

https://core.ac.uk/download/154424202.pdf

Probably sounds about right children are naturally the highest risk group with the highest percentage of fatal stings.

I just know the modern estimated mortality rate for H. tamulus stings is commonly quoted as below 4% regardless of any specific risk groups.

 

[Supreme]

do you know if you have a male or female? i have a female and wanna breed it but dont have a male. but my female wont reach sexual maturity for at least a few months. and do you know what instar yours is? also any pictues?

Size 5i, gender unknown. I'm waiting for it to be delivered home. The picture from the previous owner looks like a female.

 

[Johnn]

Size 5i, gender unknown. I'm waiting for it to be delivered home. The picture from the previous owner looks like a female.

ok cool. i hope your scorp comes in good health

Probably sounds about right children are naturally the highest risk group with the highest percentage of fatal stings.

I just know the modern estimated mortality rate for H. tamulus stings is commonly quoted as below 4% regardless of any specific risk groups.

yeah because of prozasin. also apparently H. tamulus produces about 6 mg of venom, meaning it has 4 hard stings.

Effect of Milking Method, Diet, and Temperature on Venom Production in Scorpions

Abstract. In the present study, two common buthid scorpions, i.e., Androctonus finitimus (Pocock, 1897) (Scorpiones: Buthidae) and Hottentota tamulus (Fabr

academic.oup.com

 

[Johnn]

I'd also like to know the amount of venom injected for each type of sting as well, especially which serrulatus vs tamulus are more dangerous in 1 hit. Of course serrulatus has a stronger LD50 but how much venom is injected? want to know

actually t serrulatus injects up to .62 mg of venom per sting.

 

[Supreme]

I have Death Stalker, A.australis tunisia ,A.gonneti, A.bicolor, tamulus, serrulatus.
Observing all behaviors, tamulus appear to be more aggressive than other species. When using forcep to rake , other species will walk away, but tamulus charges forward with a 2-3 hit with a stinger.

 

[Johnn]

I have Death Stalker, A.australis tunisia ,A.gonneti, A.bicolor, tamulus, serrulatus.
Observing all behaviors, tamulus appear to be more aggressive than other species. When using forcep to rake , other species will walk away, but tamulus charges forward with a 2-3 hit with a stinger.

From my personal experience that is true also. I. Have a australis a bicolor had LQs and they were eaten
My. H tamulus is my favorite. Did you ever sex yours?