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Poisonous Animals
FrogsSnakes  Apids,Vespids,AntsSpiders  Scorpions  Lizards  Marine animals  Birds

Frogs of the family Dendrobatidae are commonly known as Poison Frogs
or Dart-Poison Frogs, since are used by natives of the Choco region of Columbia
to poison blowgun darts used for hunting birds and mammals.
Seven genera of Anurans have been discovered to contain potent alkaloid toxins on the skin :
4 genera are in the family Dendrobatidae:
genus Dendrobates, Epipedobates, Minyobates and Phyllobates;
the other 3 genera being:
Mantella [Madagascar], Melanophryniscus [South America] and Pseudophryne [Australia].
The skin of such Amphibian has provided over 400 alkaloids of over 20 structural classes;
these include the batrachotoxins, histrionicotoxins, pumiliotoxins and epibatidine .
Batrachotoxin, the most powerful animal venom known
 [250 times more powerful than strychnine],
is produced by the dart-frog Phyllobates terriblis.
[Daly, J.W., 'Thirty years of discovering arthropod alkaloids in amphibian skin', 1998, J. Nat. Prod., 61(1), 162-172;
Daly, J.W., Myers, C.W. & Whittaker, N., 1987, Toxicon 25(10), 1023-1095;
Daly, J.W., 1995, 'The chemistry of poison in amphibian skin', Proc. Natl. Acad. Sci. USA  92, 9-13; ]
The minimum lethal dose of the batrachotoxin in a 20-gram mouse is 0.05 mg;
the amount of toxin/frog-skin averages 1,100 mg;
a single P. terriblis has enough poison to kill upwards of 20,000 mice, or 10 to 100 humans Anura.htm ]
There exists over 165 different types of arrow-poison frogs
Epipedobates tricolor is one of  the most poisonous frogs known,
being capable of knocking out a huge water  buffalo.
The highly toxic alkaloid called epibatidine, isolated from the skin of this Ecuadorian tree frog,
produces muscle paralysis and cardiorespiratory depression, eventually leading to death
[Marwick C, 1998, J. of Am. Med. Ass., 279(21): 1679-81]

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Of 100,000 snake bites in the United States over the past years, only 12 resulted in fatalities
[mostly in children, the elderly, members of religious sects]] ,
while more fatalities result in Africa: 1,000 deaths; in Brazil, Ecuador and Venezuela: 3,000 deaths;
in India and Pakistan: 8,000 deaths; and in the Middle East: 20,000 deaths.
About 450 of the 3000 species of  venomous snakes
are considered poisonous to humans.
The most important are listed below, by common names:

Black mamba, Africa,100% mwa
Boomslang, hm [=high mortality]
Carpet viper, vhm [=very hm]
Desert horned viper, lm
Gaboon viper,  (?)
Puff adder, mm
Spitting cobra,  >> blindness
Yellow cobra, hm

Pit viper ,  lm [=low mortality]
Cobra,  10%m
Russell's viper,  mm [=moderate mortality]
King cobra, lm
Krait,  50% mwa [=mortal without antiserum]
Sharp-nosed pit viper, mm
Sea snakes [Indian ocean & west Pacific ocean], lm

Brown snake, mm
Death adder, 50%mwa
Taipan, 100% mwa
Tiger snake, vhmwa

South America
Barba amarilla, mm
Bushmaster, hm

Copperhead, lm
Coral snake, hm
Cottonmouth water mooccasin, lm
Rattlesnake, lm

Viper, lm

               Of Queensland’s 80 known species of land snakes,
                the 16 listed below are potentially fatal:
[common name, scientific name]
                                Western Taipan, Oxyuranus microlepidotus
                                Coastal Taipan,  Oxyuranus scutellatus
                                Tiger Snake,  Notechis scutatus
                                Common or Eastern Brown Snake, Pseudonaja textilis
                                Mulga or King Brown Snake,  Pseudechis australis
                                Papuan Black Snake,  Pseudechis papuanus
                                Common Death Adder,  Acanthophis antarcticus
                                Northern Death Adder,  Acanthophis praelongus
                                Hawke's Death Adder,   Acanthophis hawkei
                                Desert Death Adder,  Acanthophis pyrrhus
                                Western Brown Snake,  Pseudonaja nuchalis
                                Collett's Black Snake,   Pseudechis colletti
                                Red-bellied Black Snake,  Pseudechis porphyriacus
                                Spotted or Blue-bellied Black Snake, Pseudechis guttatus
                                Small-eyed Snake, Cryptophis nigrescens
                                Rough-scaled Snake,  Tropidechis carinatus
                                                [from : Queensland Museum]
Saw-scaled vipers, Echis carinatus, live in sandy soil and rock in Africa, India and  Middle East;
Echis carinatus is probably the world's deadliest snake.
[ ]
The venom injected in a single bite from  the snake
Oxyuranus microlepidotus
is sufficient to kill ~100 adult humans.

Statistics also reveal that of snakebite victim deaths,
17% died 1 to 12 hours after being bitten
and 64% between 12 hours and 2 days.
[ University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS)]

Sub-cutaneous LD50 of 20 most poisonous snake venoms,
according to B. G. Fry
[ ]

Scientific name
Common name
LD-50, mg/Kg
Oxyuranus microlepidotus
Inland taipan
Pseudonaja textilis
Eastern brown snake
Aipysurus duboisii
Dubois's sea snake
Pelamis platurus
Yellow bellied sea snake
Acalyptophis peronii
Horned sea snake
Oxyuranus scutellatus
Coastal taipan
Bungarus multicinctus
Many banded krait
Hydrophis melanosoma
Black banded sea snake
Enhydrina schistosa
Beaked sea snake
Boulengeria christyi
Congo water cobra
Notechis a. niger
Peninsula tiger snake
Boulengeria annulata
Banded water cobra
Echis carinatus
Saw-scaled viper
Hydrophis stricticollis
(sea-snake species)
Hydrophis major
Olive-headed sea snake
Notechis a. occidentalis
Western tiger snake
Crotalus tigris
Tiger rattlesnake
Notechis scutulatus
Mainland tiger snake
Hydrophis elegans
Elegant sea snake
Aipysurus laevi
Olive sea snake

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Apids [honeybees, bumblebees],
vespids [wasps, yellow jackets, hornets],
and Ants

In the USA, stings cause 3 to 4 times more deaths than do venomous snakebites.
Millions of people in the United States are injured from venoms produced by insects
and other arthropods each year. Of these injuries about 25,000 result in severe injuries
and about 32 result in deaths.
The average person can safely tolerate 10 stings/lb body weight;
the average adult can withstand >1000 stings,
whereas 500 stings can kill a child.
However, one sting can cause a fatal anaphylactic reaction in a hypersensitive person;
more often, toxic reactions to Arthropods venom components,
may manifest clinically as anaphylaxis,
after 50 to 100 stings.
Insect stings result in rapid progression of toxic effects.
Of 208 deaths, 80% occurred
less than one hour after being stung by Hymenoptera
(bees, wasps, yellow jackets, or hornets).

Imported fire ants account for two thousands of stings each year .
There are several fire ants species, but Solenopsis invicta predominates
            and is responsible for an increasing number of allergic reactions.
In infested urban areas,
as much as 40% of the population may be stung each year.
Fire ant venom has hemolytic and cytolytic properties.
Anaphylaxis due to fire ant stings probably occurs in < 1% of patients.

Average Deaths from Venomous Pests

Number of Deaths /Year
Insects & Related Pests
Yellow Jackets
[University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS), modified]

The most studied Pests' neurotoxins

Honey bee Apis mellifera
Wasp Philanthus triangulum
Tick Ixodes holocyclus

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    Almost all of the 20,000 species of spiders are  venomous.
At least 60 species in the USA have been  implicated in bites on humans.
    In the USA in 1996, 13,167 spider bites  were reported to 67 poison control centers
that served 87% of the population.
Of greatest significance are those possessing neurotoxic [widow spiders]
and necrotizing [brown or violin spiders and some house spiders] venom components.
The most toxic component of widow spider, Lactrodectus sp.,
venom Latrotoxin appears to be a peptide affecting neuromuscular transmission.
Poisoning by the widow spiders is termed latrodectism;
while poisoning by the recluse spiders, genus Loxosceles, is known as loxoscelism.
Poisoning caused by the hobo spider, Tegenaria agrestis,
may be properly termed tegenarism.
 Species often implicate in envenomations are:
L. mactans
L. hasselti
L. hesperus
L. indistinctus
L. menavodi
L. tredecimguttatus
L. variolus
all of which usually provoke somewhat similar clinical pictures.
[Jelinek, G.A., 1997, Wilderness Environ. Med., 8(4), 226-231]
   About 15% of envenomated subjects are poisoned severely enough to require hospitalization;
sometime aplastic anemia can develop several weeks after the bite, leading to a fatal outcome.
        [Darwin K. Vest, Eagle Rock Research; Nocholson & al., 1998, Pflugers Arch., 436(1), 117-126; Nicholson, G.M. & Graudins, A., 2002, 'Spiders of medical importance in the Asia-Pacific: atracotoxin, latrotoxin and related spider neurotoxins',
Clin. Exp. Pharmacol. Physiol., 29(9), 785-794]]
  Black widow spider bites occur most frequently in the Mediterranean countries and the USA.
Some 30 minutes after its bite, the patient experiences severe pains,
which are often  projected onto the other arm or leg.
Small children can be especially endangered by a spider bite.
 The brown spider lives primarily in North and South America and the Mediterranean countries.
The first signs are fever and hives,
which then change into a muscular weakness lasting for weeks,
sensory dissociation and occasionally also kidney failure.
   Bites from bird and banana spiders are potentially fatal
[ Australia, South Africa and South America].
Spider bites, however, have a longer time interval between bites and death,
with 89% of 54 victims dying more than 12 hours after being bitten.
[ University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS)]
Only a few spider venoms have been studied in detail.

The best known neurotoxins produced by spiders

Funnel web spider Agelenopsis aperta
Funnel web spider Agelenopsis aperta
Tarantula Hysterocrates gigas
Chinese bird spider
Joro-spider toxin
Joro spider
Black widow Latrodectus mactans
Banana spider Phoneutria nigriventer
Chilean fire tarantula
Funnel web spiderAgelenopsis aperta
African tarantula
Funnel web spiderAgelenopsis aperta

FrogsSnakes  Apids,Vespids,AntsSpiders  Scorpions  Lizards  Marine animals  Birds

Although there are over 1050  different species of scorpions world-wide,
relatively few of them are poisonous to man.
One such highly poisonous scorpion is the Leiurus quinquestriatus
found predominantly on the Israeli deserts.
Also called the 'Death Stalker' or  'Yellow Scorpion',
Leiurus quinquestraitus produces one of the most potent venoms of all scorpions.
It has an LD50  of about 0.3 mg venom/kg mouse
compared to an LD50 of 1.45 mg venom/kg mouse
in the Mesobuthus eupeus scorpion of Iran.
The main neurotoxins of the Leiurus quinquestriatus venom are chlorotoxin and charbydotoxin
The scorpion Tityus serrulatus produces the neurotoxin tityustoxin
[Romano-Silva et al., 1994, Biochem. J., 304, 353-357].
The venom of  Centruroides exilicauda (sculpturatus),
causes immediate pain and some numbness or tingling over the involved part.
Children become tense and restless, display abnormal and random head, neck, and eye movements.
In adults, tachycardia, hypertension, increased respirations, weakness,
and motor disturbances may   predominate.
Respiratory difficulties may occur in children and adults, often complicated by excessive salivation.
C. exilicauda stings have resulted in death in children < 6 yr and in hypersensitive persons.

The most studied toxins of Scorpions

T o x i n 
S c o r p i o n
Agitoxin Leiurus quinquestriatus hebraeus
Charybdotoxin Leiurus quinquestriatus hebraeus
Iberiotoxin Buthus tamulus
Imperatoxin Pandinus imperator
Kaliotoxin Androctonus mauretanicus m.
Margatoxin Centruroides margaritatus
Noxiustoxin Centruroides noxius hoffmann
Tityustoxin Tityus serrulatus

FrogsSnakes  Apids,Vespids,AntsSpiders  Scorpions  Lizards  Marine animals  Birds
The best known venomous lizards are the Gila monster Heloderma suspectum
and the beaded lizard  H. horridum.
Their venom is similar to that of some pit vipers.
Most common manifestations are weakness, sweating, thirst,  headache, tinnitus.
Cardiovascular collapse sometimes occurs.

FrogsSnakes  Apids,Vespids,AntsSpiders  Scorpions  Lizards  Marine animals  Birds


There are over 500 species of cone snails, marine animals found in  coastal areas.
Each species produces many different venoms .
The venoms of Conus geographus are fatal to humans 70% of untreated cases.
Conotoxins, the most potent neurotoxins produced by C. geographus,
are small peptides, normally only 20-30 aminoacids in length.
Coelenterates are responsible for more envenomations than any other marine animal.
Of the 9000 species, about 100 are toxic to humans.
Coelenterates, including the corals, sea anemones, jellyfishes, and hydroids (as Portuguese man-of-war),
have a highly developed stinging unit (the nematocyst) that  can penetrate human skin.
Systemic  manifestations include weakness, nausea, headache, muscle pain and spasms,
lacrimation and  nasal discharge, increased perspiration, changes in pulse rate, and pleuritic chest pain.
In North  American waters, the Portuguese man-of-war has caused several known deaths.
Members of the Cubomedusae order are the most dangerous of coelenterates,
particularly the sea wasp Chiropsalmus quadrigatus
and the box jellyfish Chironex fleckeri
have been responsible for several deaths in Indo-Pacific waters.
The Box JellyfishChironex fleckeri, also known as sea wasp, sea stinger
is higly lethal to humans: death within 5 minutes is possible.

FrogsSnakes  Apids,Vespids,AntsSpiders  Scorpions  Lizards  Marine animals  Birds

"Three passerine species in the genus Pitohui,
endemic to the New Guinea subregion,
contain the steroidal alkaloid homobatrachotoxin...
Toxin concentrations .. are highest in the skin and feathers."
Some homobatrachotoxin is also present in muscle tissue.
[Dumbacher et al., 1992, Science 258, 799-801]
Homobatrachotoxin is one of the most toxic neurotoxins, collectively called batrachotoxins,
produced by the most poisonous dart-poison Frogs of the genus Phyllobates .
The most toxic species is Pitohui dichrous;
less toxic are P. kirhocephalus and P. ferrugineus.
The death of laboratory mice injected with skin extracts of Pitohui
does occur within 18-19 minutes,
as if injected with 0.05 µg of homobatrachotoxin.
[Dumbacher et al., 1992, Science 258, 799-801]