- Aug 23, 2019
Big spider, big 'tude. Sadly one of the most maligned venomous spiders in the world.
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0036-46652000000100003&lng=en&tlng=enI know that vid and also the others from him. Not smart imho but i think he "kind of" knows what he's doing and i guess if he'd have get tagged he at least hadn't blamed the spider.
I find the end of this clip quite funny though. As soon as the lady starts to get crabby he's very fast to end the video. I wonder if he knew that the spider could have got him at any time if it had wanted.
Worldwide, there are approximately 40,000 described spider species, most of which use venom to subdue prey. Of these, very few are medically important to people. Before 2000, spiders were estimated to be responsible for fewer than 200 deaths per year globally (Nentwig and Kuhn-Nentwig 2013). Per million people, spiders killed between 0.02 and 0.04 people per year. In comparison, snakes and scorpions respectively caused 20 and 0.1-1.4 fatalities per million people each year. The most medically important spiders include the widow spiders (Latrodectus, Theridiidae), the recluse spiders (Loxosceles, Sicariidae), the Australian funnel-web spiders (Atrax and Hadronyche, Hexathelidae) and armed spiders (Phoneutria, Ctenidae) (Vetter and Isbister 2008). In the past three decades, there have not been any confirmed fatalities due to envenomation by widow spiders, Australian funnel-web spiders or armed spiders (Nentwig and Kuhn-Nentwig 2013). Among the recluse spiders, bites are easily misdiagnosed, making it difficult to determine figures regarding their bites. Despite the low frequency of fatalities attributed to these taxa around the world, bites from species in these groups, including Phoneutria,can be serious and often require medical treatment.
As with other spiders of medical importance, venom is injected into prey or defensively into potential predators through the fangs (Figure 9). Venom is produced by glands located in the chelicerae (structures on the face, immediately above the fangs). The venom of Phoneutria spiders consists of a mixture of proteins and peptides that are active against the nervous systems of both invertebrates and vertebrates (Gomez et al. 2002). Among species in the genus, venom composition and potency vary, with Phoneutria nigriventer and Phoneutria keyserlingi having particularly potent venoms (Vetter and Hillebrecht 2008). While these and other Phoneutria species are primarily associated with forested habitats, Phoneutria nigriventer and Phoneutria keyserlingi can occupy habitats in rural and urban areas. Both species also are frequently found inside human dwellings, where they prey on cockroaches and other pest arthropods. As a result, bites from these and other Phoneutria species are common. For example, in 2006, 2,687 cases of envenomation were treated in Brazil alone (Bucaretchi et al. 2008).
Figure 9. Close up of fangs, chelicerae (note reddish hairs) and palps of Phoneutria species. Photograph by Lawrence Reeves, University of Florida.
Over the past 100 years, 10 fatalities have been attributed to Phoneutria spiders, mostly among young people (Nentwig and Kuhn-Nentwig 2013). In comparison, similar numbers of fatalities are reported for the widow spiders and Australian funnel-web spiders. While cases of mortality are known, in the majority of cases (90%), Phoneutria envenomation is considered to be mild and only 0.5-3.3% are diagnosed as severe or systemic (Bucaretchi et al. 2008). The effects of envenomation include severe pain, elevated heart rate, arterial hypertension, cardiac distress, shock, muscle tremors, priapism and frequent vomiting (Gomez et al. 2002). These symptoms can be particularly pronounced in children. In Brazil, moderate and severe cases (about 3% of cases) of envenomation are treated with anti-venom but are otherwise treated symptomatically (Bucaretchi et al. 2016).
Envenomation by Phoneutria spiders is a reasonable concern only within their native range. These species are common in forested habitats, but also will occupy populated and agricultural areas, bringing them into contact with humans. Accidents are particularly common in banana plantations, where the spiders often seek shelter in bunches of bananas during the day. This behavior enables their accidental importation into areas outside of their natural Neotropical distribution. Phoneutria species have been intercepted in Europe and North America (Vetter and Hillebrecht 2008, Vetter et al. 2014). Of the Phoneutria species, Phoneutria boliviensis is the most common spider intercepted in international shipments, in part because it is the species with the widest distribution. Many banana and other agricultural shipments originate in Central America, where this species occurs.
Compared to other Phoneutria species, the venom of Phoneutria boliviensis is less potent, and envenomations are typically mild (Vetter and Hillebrecht 2008). The Phoneutria species with the most potent venoms, Phoneutria nigriventer and Phoneutria keyserlingi, are not widely exported because they occur in Brazil, where much of the country’s banana crop is consumed locally. In addition, most other Phoneutria species occur in regions of Brazil or the Amazon that are sparsely populated and produce few internationally traded products. Vetter and Hillebrecht (2008) also caution against the misidentification of Phoneutria with the essentially harmless genus, Cupiennius. Cupiennius share some morphological characters with Phoneutria, including a large body size and red hairs on the chelicerae (in some species). Like Phoneutria, they are common in agricultural settings, particularly banana plantations.
The dangers associated with these spiders for North Americans are very much overexaggerated. First, the most cited dangerous species is Phoneutria fera. This is actually an Amazonian species, (i.e., it lives in the Brazilian Amazon) far from areas of human commerce and the Brazilian banana plantations and, therefore, they don’t have the opportunity to be transported in cargo, or at least are highly unlikely to be so moved. In Germany from decades ago, specimens listed as imported P. fera were most likely misidentified specimens of other Phoneutria species. (One must also keep in mind that Phoneutria taxonomy has been a nightmare for the last century with new species being named and other names being absorbed by other existing species, back and forth almost like an Abbott and Costello comedy routine. It is really difficult sometimes to pin down a name because for some spider groups, the taxonomy is not yet settled). The spiders intercepted in Germany were most likely specimens of P. nigriventer and P. keyserlingi, which are only found on the Atlantic coast of Brazil and are mostly involved in Brazilian envenomations. All three of these spiders can get up to 50 mm in body length. However, they still are not nearly as deadly as people claim. In one study of 422 Phoneutria bites in coastal Brazil, only 2.3% of the victims required antivenom and the only death was one small child. Although there is an obvious major concern when children are bitten, most bite victims experienced minor problems without long-lasting effects and certainly not death. Most of the bites were in adults; minor symptoms resolved without complications.
Although these large spiders were transported in bananas to Europe many years ago, currently, Brazil consumes almost all of its banana crop domestically so now there is less chance for the spiders to be transported out of the country, at least in fruit.
On the west coast of South America, another species, P. boliviensis, exists and has occasionally been transported in cargo to North America (mostly from Ecuador). However, in comparison to its eastern relatives, this species is smaller (30 mm body length) and its envenomation effects are milder. A paper on bites in plantation workers revealed annoying symptoms but no deaths. Workers missed 2 to 3 days of work. So even if these spiders were transported to North America, they are not considered very dangerous and should not cause concern.
- The dangerous species of Phoneutria are found in the Amazon where interaction with people is rare and transport out of the country in commerce is highly unlikely.
- The two species associated with high human population on the eastern Brazilian coast cause human envenomations but are not as dangerous as they are reported to be. Although they can cause death in young children, most bite victims experience mild reactions.
- Brazil no longer exports much of their banana crop.
- The western South American species of Phoneutria is much smaller than the eastern species and although sometimes is transported, it is not a major medical concern when bites occur.
- All Phoneutria species are virtually restricted to South America. If a spider is found in a banana shipment from Central America, then it is highly unlikely to be a Phoneutria spider (see next section)
True, they need to be respected but they don't deserve to be vilified as deadly either (as in a "jumping fanged cyanide capsule"). There are even handling videos on youtube (not at all recommended) but when handled properly they aren't the venom dripping monsters most of us perceive them to be. Just be careful with them and don't handle them.I would still say that Phoneutria should be regarded with the utmost caution. When it comes to potentially fatal species, comparison between species and genera can be very dangerous.
Otherwise, I'd say that you are absolutely right in saying that these are not public enemies, rather being used by the media to create a fear of arachnids most of the time. They should still command respect however.
Why can't people keep things in context instead of building a major melodrama?Big spider, big 'tude. Sadly one of the most maligned venomous spiders in the world.