UNIT XV Poisonous and Venomous Vertebrates

Ecological role of toxins Toxin

Definition an antigenic poison or venom of plant or animal origin, esp. one produced by or derived from microorganisms and causing disease when present at low concentrationinthebody.

in Oxford American dictionaries Ecological role of toxins

1. Interactions with predators 1a. a. Defense at close contact b. “Remote” defense 2. Interactions with prey 3. Interactions with competitors 4. Protection against fungi and bacteria 1b. 2. 3. 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 Vertebrates

There are around 40,000 species of vertebrates and around 2,000 are venomous. Fish 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 Opercular spines

Venomous fangs

Echiichthys vipera 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 Blenny Fangs

Meiacanthus nigrolineatus

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Meiacanthus nigrolineatus

Meiacanthus grammistes Predation Protection in the Poison-Fang Blenny, Meiacanthus atrodorsalis, and Its Mimics, Ecsenius bicolor and Runula laudandus (Blenniidae) GEORGE S. LOSEY PACIFIC SCIENCE, Volume 26, April 1972

Predator reaction to ingestion of a M.atrodorsalis ?

Role of venomous canines of Meiacanthus atrodorsalis ? Feeding experiments with Poison-Fang Blenny and its mimics

Reaction to ingestion: Violent quivering of the head with

distension of the jaws and QuickTime™ and a operculi. The fish frequently TIFF (Uncompressed) decompressor are needed to see this picture. remained in this distended posture for several seconds until the M. atrodorsalis emerged from their mouth. Amphibians 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) 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; TETRODOTOXIN LEVELS IN EGGS OF THE ROUGH-SKIN NEWT, Taricha granulosa, ARE CORRELATED WITH FEMALE TOXICITY CHARLES T. HANIFIN;EDMUND D. BRODIE 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? 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

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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) 2 =Female TTX*3968+735 is significant (F1;9 = 8.128; R =0.48; P=0.019). Reptiles 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) What about poisonous snakes? Rhabdophis tigrinus Dietary sequestration of defensive steroids in nuchal glands of the Asian snake Rhabdophis tigrinus Deborah A. Hutchinson, Akira Mori, Alan H. Savitzky, 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? Feeding experiment

Rhabdophis tigrinus Bufo sp.

QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. 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. Birds Pitohui dichrous

Ifrita kowaldi

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

QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Mammals 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. Slow Loris Nycticebus coucang 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. Glands of lorises Traumatizing apparatus

• Nycticebus cougans may also use biting as a way of delivering the toxin.

• They use the toothcomb to inject the poisonous saliva. The End References

1. 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(3:206-217 2. Bücherl, Buckley,Deulofeu.Venomous Animals and Their venoms. 1968. Academic Press 3. G. G. Habermehl. Venomous Animals and their toxins. 1981. Springer-verlag 4. 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 5. Sindhu Radhakrishna & Mewa Singh.?.Social Behaviour of the Slender Loris (Loris tardigradus lydekkerianus)? 6. 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 7. 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 8. 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 9. Lev Fishelson. 1974. Histology and ultrastructure of the recently found buccal toxic gland in the fish Meiacanthus nigrolineatus (Belnnidae). Copeia No 2 10. BECKY L. WILLIAMS,EDMUND D. BRODIE, JR., and EDMUND D. BRODIE III . 2004. A RESISTANT PREDATOR AND ITS TOXIC PREY:PERSISTENCE OF NEWT TOXIN LEADS TO POISONOUS (NOT VENOMOUS) SNAKES .Journal of Chemical Ecology, Vol. 30, No. 10 11. 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) 90:60–62

Websites: 1. http://animaldiversity.ummz.umich.edu/site/accounts/information/Nycticebus_coucang.html 2. http://www.venomdoc.com/ 3. http://www.loris-conservation.org/database/disease/1-4_anatomy_skin_glands.html 4. http://uts.cc.utexas.edu/~bramblet/ant301/eight.html#anchor1078942 5. http://www.cosmosmagazine.com/node/1423 6. http://www.livescience.com/animals/070129_toad_toxin.html 7. www.wikipedia.com