poisonous redback spider
Post on 18-Jul-2015
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Contents
What is Redback SpiderHabitatsTheir figureTheir lifecycleVenomSymptomTreatment and careConclusion
What is Redback Spider?
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Adult female
Adult male
The redback spider (Latrodectushasseltii), also known as the jockey spider, is a species of poisonous spider indigenous to Australia.
The redback is one of the few spider species that can be seriously harmful to humans, and its preferred habitat has led it to being responsible for the large majority of serious spider bite in Australia.
Red pattern on the back
Color and shapeRed pattern also stomach
Fang(0.7mm)
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Even if bitten from the top of the clothes, it does not reach the skin.
Size
Male
FemaleMale : 3~5mmFemale : 10~15mm
Female only has a poison, there is no poison in the male.
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Where does Redback Spider Live?
• Sunny, warm place• Where there is plenty of food, such as insects or small animals• Where there is a suitable gap to put the nest
The back of groove Fence Under the planter7
Lifecycle of Redback Spider
JuvenileAdult
Eggs
Internal sac of one egg : 100~200
Egg sac
Male : 58~75 daysFemale : 75~104 days
They work in June-September
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Their venomVenom is produced by glands in the cephalothorax, and expelled venom travels through paired ducts from the cephalothorax, exiting through the tip of the spider's hollow fangs.
Venomgland
Fang
Venom protein
Muscular layerFang and venom gland of redback spider Microstructure of venom gland
of redback spider 10
Component of the venomName : α-latrotoxin (neurotoxin)
King Cobra : 1.75mg/kgRedback Spider : 0.59mg/kg
Features of α-latrotoxin
The only toxic to vertebrate Toxin which is effective in the presynaptic membrane Toxic effect of promoting the depolarization of the
central nervous system of vertebrates
TOXICITY (Comparison of LD50)
Their poison is stronger than snake’s it. 11
Actions of α-latrotoxinα-latrotoxin is allowed to flow to force the Ca ion by acting from outside the neuron to calcium channels of axon terminals.
Neurotransmitter is released all and we provoke such seizures abnormally excited the muscle fibers or neurons
Information transmission function of the nervous system is paralyzed.
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SymptomImmediately after being bitten
When redback spider bites, almost no pain topical immediately after being bitten and only feel a slight pain at a site bitten even. In some cases, stab mouth is found one or two.
5~60 minutes after being bitten
Local symptoms appear, pain will increase gradually.
60 minutes~ after being bitten
Pain bitten over time spread to the entire limb. Local sweating also occur, warmth, itching also often associated with. However, the greatest feature of the local symptoms is pain.
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If we are bitten…
We don’t die by their poison because injection amount of their poison is a little.
If the treatment is delayed, we cause muscle paralysis or skin rot.
However…14
Bite treatment and care If we are bitten by redback spider, we have to wash the area
of the bite with soap and water.
Even if there is bleeding, it is not necessary to the tourniquet and bandage.
Chilled on ice the wound, to go to the hospital.
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How to removeIf you found a redback spider, you must not touch it with bare hands.
Spraying Stomping Burning
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Conclusion
The adult female redback spider has a round body about 1 cm long, with long, slender legs. The body is a deep black (occasionally brownish), with a red (sometimes orange) longitudinal stripe on the upper abdomen.
The poison that they have is very strong to the vertebrate. However, if you do not do anything for them, they will not bite.
If we are bitten by them, appropriate care is necessary.
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History of Redback spider① 1870 : Swedish aracheologist Tamerlan Thorell described the
redback spider from specimens collected in Rockhampton and Bowen in central Queensland
He named it Latrodectus hasselti in honour of collegue A.W.M van Hasselt.
1902 :German arachnologist Friedrich Dahl revised the genus and named L.ancorifer from New Guinea, which was later regarded as a subspecies of the redback.
1911 : Another subspecies , L. h. aruensis , was described byNorwegian entomologist Embrik Strand.
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History of Redback spider② 1959 : Arachnologist Herbert Walter Levi revised the genus
Lactrodectus.
He focused on differences in the morphology of the female sexual organs, he reclassified the genus reducing the number of recognized species from 22 to 6.
~Recently : More reliable genetic studies have split the genus into about 30 species, and the redback has no recognized subspecies in modern classifications.
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Nest of Redback spider
The nest that they build is irregular and have a three-dimensional structure strung complicated.
Nest area
Capture area
Mucus of capturing is attached to the thread.
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Fatal caseRedback spider bites rarely cause chronic morbidity , and deaths are even more rare. Throughout the history, at least 14 deaths from redbacks have been recorded. Children, the elderly, or those with serious medical conditions are at much higher risk of severe effects and death resulting from a bite.
DangerousDangerous
Dangerous
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Relationship with humansTheir net is used to cross line of optical instruments surveying instruments, rangefinder, microscope, bombsight, such as telescopic sight.
The study that made full use of genetic engineering, and a thread of this spider is produced to bacteria is going by the fund of the United States Army.
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