Poisonous and Venomous Vertebrates Ecological role of toxins

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Poisonous and Venomous VertebratesEcological
role of toxins
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Toxin
Definition an antigenic poison or venom of plan
t or animal origin, esp. one produced by or
derived from microorganisms and causing disease
when present at low concentration in the body.
in Oxford American dictionaries
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Ecological role of toxins

• Interactions with predators
• Defense at close contact
• Remote defense
• Interactions with prey
• Interactions with competitors
• Protection against fungi and bacteria

1a.
1b.
2.
3.
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Poisonous or Venomous?
Poisonous producing poison as a means of
attacking enemies or prey toxic substances which
are absorbed through epithelial linings such as
the skin or gut.
Poisonous dart frog
Venomous secreting venom capable of injecting
venom by means of a bite or sting.
Gaboon viper
in Oxford American dictionaries
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Vertebrates
There are around 40,000 species of vertebrates
and around 2,000 are venomous.
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Fish
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Fish
There are 28,000 species of bony fish , and
around 1,200 are venomous.
There is large diversity in the traumatizing
apparatus Venomous spines Dorsal spines Oper
cular spines
Venomous fangs
Echiichthys vipera
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Meiacanthus atrodorsalis
Presence of a compound buccal gland in the blenny
is a new organ for teleost fishes.
This gland has a toxic secretion that can be
injected into the "victim" through specialized
fangs
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Blenny Fangs
Meiacanthus nigrolineatus
Meiacanthus nigrolineatus
Meiacanthus grammistes
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Predation Protection in the Poison-Fang Blenny,
Meiacanthus atrodorsalis, and Its Mimics,
Ecsenius bicolor and Runula laudandus
(Blenniidae) GEORGE S. LOSEY PACIFIC SCIENCE, V
olume 26, April 1972
Predator reaction to ingestion of a
M.atrodorsalis ?

Role of venomous canines of Meiacanthus
atrodorsalis ?

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Feeding experiments with Poison-Fang Blenny and
its mimics
Reaction to ingestion Violent quivering of the h
ead with distension of the jaws and
operculi. The fish frequently remained in this
distended posture for several seconds until the
M. atrodorsalis emerged from their mouth.
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Amphibians
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Amphibians

• There are several species of poisonous
  amphibians. These include
  
• Anura
• (e.g. Bufos marinus
• and Phyllobates terribilis)

• Caudata (e.g. terrestrial phase of Notophthalmys
  viridescens and Triturus marmoratus)

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Taricha granulosa

• The rough-skin newt possesses high levels of the
  neurotoxin tetrodotoxin (TTX) in its skin
  
• Tetrodotoxin serves as a defensive compound in
  adult newts

Toxin is concentrated in the granular glands of
the skin It is also present in other tissues,
including ovaries, ova, and eggs
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TETRODOTOXIN LEVELS IN EGGS OF THE ROUGH-SKIN
NEWT, Taricha granulosa, ARE CORRELATED WITH
FEMALE TOXICITY CHARLES T. HANIFINEDMUND D. BROD
IE III, and EDMUND D. BRODIE JR.
Journal of Chemical Ecology, Vol. 29, No. 8,
August 2003

• What is the TTX toxicity of individual T.
  granulosa eggs with a known family
  structure, (i.e., from clutches for which the
  female toxicity is known)?
• What is the origin of the TTX in the eggs?

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TETRODOTOXIN LEVELS IN EGGS OF THE ROUGH-SKIN
NEWT, Taricha granulosa, ARE CORRELATED WITH
FEMALE TOXICITY CHARLES T. HANIFIN,1 EDMUND D.
BRODIE III,2 and EDMUND D. BRODIE JR.1
Journal of Chemical Ecology, Vol. 29, No. 8,
August 2003
Graph of egg toxicity versus female toxicity
showing a correlation between female toxicity (on
the x axis) and mean egg toxicity per clutch (on
the y axis). The regression line Mean Clutch TTX
(MCT) Female TTX3968735 is significant (F19
8.128 R20.48 P0.019).
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Reptiles
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• Reptiles

• Venomous reptiles are only found within the order
  Squamata. Specifically
  
• Genus Heloderma
• (Heloderma suspectum
• and Heloderma horridum)
• Snakes (Elapidae, Hydrophiidae, Viperidae,
  Crotalidae)
  
• There are around 2000 species of snakes (2900)
• Around 400 species are venomous (725)

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What about poisonous snakes?
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Rhabdophis tigrinus
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Dietary sequestration of defensive steroids in
nuchal glands of the Asian snake Rhabdophis tigri
nus Deborah A. Hutchinson, Akira Mori, Alan H. Sa
vitzky, Gordon M. Burghardt, Xiaogang Wu, Jerrold
Meinwald, and Frank C. Schroeder
PNAS February 13, 2007 vol. 104 no.7
Japanese snake that occurs in small japanese
islands and in the main island of japan.
Behavioral observations showed that Snakes on
Japanese islands with a plentiful toad population
would arch their neck and display their toxic
neck glands when a predator as present, but those
on toad-free islands the snakes usually fled.
What is the origin of the toxin in the neck
glands?
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Feeding experiment
Rhabdophis tigrinus
Bufo sp.
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Another Poisonous snake.
Thamnophis sirtalis - Gartersnakes

• Feed upon the Rough-skinned Newt (Taricha
  granulosa)
  
• TTX can stay in the liver for 1 month or more
  after consuming just one newt
  
• The poison can stay at least 7 weeks after
  consuming a diet of newts.
  
• This amount could be lethal to the birds and
  mammals that prey upon
  
• Gartersnakes.

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Birds
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Pitohui dichrous
Ifrita kowaldi
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(No Transcript)
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Melyrid beetles (Choresine) A putative source
for the batrachotoxin alkaloids found in
poison-dart frogs and toxic passerine birds
John P. Dumbacher, Avit Wako, Scott R.
Derrickson, Allan Samuelson, Thomas F. Spande ,
and John W. Daly PNAS November 9, 2004 vol.
101 no. 45

• Birds feed on a variety of insects of the same
  size and even
  
• from the same Genus as Choresine beetles
• Choresine beetles are potentially a direct
  source of
  
• batrachotoxins for toxic New Guinea birds

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• Mammals

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Ornithorhynchus anatinus

• The venom apparatus is only present in males

• Crural gland only secretes venom in breeding
  season
  
• The use of the venom apparatus is probably
  related to combat with other males for territory
  or females.

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Slow Loris Nycticebus coucang
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Venomous and Poisonous Primate?
Nycticebus coucang inhabits the rainforests of
southeast Asia, Assam, Burma, Thailand,
Indo-China, certain Malayan states and East
Indian Islands.
Nycticebus coucang

• They have a brachial organ, a naked, gland-laden
  area of skin on surface of the arm that is licked
  during grooming.

• When mixed with saliva, the toxin can repel some
  predators.

• Anaphylaxis has been observed following loris
  bites.

• N. coucang brachial organ protein acts as an
  allergen.

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Glands of lorises
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Traumatizing apparatus

• Nycticebus cougans may also use biting as a way
  of delivering the toxin.
  
• They use the toothcomb to inject the poisonous
  saliva.

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The End
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References

• Smith, William Leo and Wheeler, Ward C. 2006.
  Venom evolution widespread in fishes a
  phylogenetic road map for the bioprospecting of
  piscine venoms.2006. Journal of Heredity
  97(3206-217
• Bücherl, Buckley,Deulofeu.Venomous Animals and
  Their venoms. 1968. Academic Press
  
• G. G. Habermehl. Venomous Animals and their
  toxins. 1981. Springer-verlag
  
• GEORGE S. LOSEY. 1972.Predation Protection in the
  Poison-Fang Blenny, Meiacanthus atrodorsalis, and
  Its Mimics, Ecsenius bicolor and Runula laudandus
  (Blenniidae). PACIFIC SCIENCE, Volume 26
• Sindhu Radhakrishna Mewa Singh.?.Social
  Behaviour of the Slender Loris (Loris tardigradus
  lydekkerianus)?
  
• William Leo Smith and Ward C. Wheeler. 2006.
  Venom evolution widespread in fishes a
  phylogenetic roda map for the bioprospecting of
  piscine venoms. Journal of Heredity 97(3)
  206-217
• Charles T. Hanifin, Edmund E. Brodie III, and
  Edmund D. Brodie Jr.2003. Tetrodotoxin levels in
  eggs of the rough-skin newt, Taricha granulosa,
  are correlated with female toxicity. Journal of
  Chemical Ecology Vol.29 no8
• John P. Dumbacher, Avit Wako, Scott R.
  Derrickson, Allan Samuelson, Thomas F. Spande ,
  and John W. Daly. 2004. Melyrid beetles
  (Choresine) A putative source for the
  batrachotoxin alkaloids found in poison-dart
  frogs and toxic passerine birds. PNAS vol. 101
  no. 45
• Lev Fishelson. 1974. Histology and ultrastructure
  of the recently found buccal toxic gland in the
  fish Meiacanthus nigrolineatus (Belnnidae).
  Copeia No 2
• BECKY L. WILLIAMS,EDMUND D. BRODIE, JR., and
  EDMUND D. BRODIE III . 2004. A RESISTANT PREDATOR
  AND ITS TOXIC PREYPERSISTENCE OF NEWT TOXIN
  LEADS TO POISONOUS (NOT VENOMOUS) SNAKES .Journal
  of Chemical Ecology, Vol. 30, No. 10
• Sonja Krane, Yasuhiro Itagaki, Koji Nakanishi,
• Paul J. Weldon.2003.Venom of the slow loris
  sequence similarity of prosimian skin gland
  protein and Fel d 1 cat allergen.
  Naturwissenschaften (2003) 906062
• Websites
• http//animaldiversity.ummz.umich.edu/site/account
  s/information/Nycticebus_coucang.html
  
• http//www.venomdoc.com/
• http//www.loris-conservation.org/database/disease
  /1-4_anatomy_skin_glands.html
  
• http//uts.cc.utexas.edu/bramblet/ant301/eight.ht
  mlanchor1078942
  
• http//www.cosmosmagazine.com/node/1423