TOXIC ANIMALS PRESENTED BY: Mrs L Mugivhisa

Course objectives Classification of toxic animals Toxin transfer structures of animals / apparatuses Venomous animals – snakes – Types of venoms produced – Structures of venom apparatuses – Clinical aspects of envenomations

Lecture 1 Objectives Definitions of & correct usage of technical terms – Poison – Toxin – Venom Define & Distinguish between 2 groups of toxic animals: – Poisonous animals – Venomous animals

Introduction Basic knowledge & identification of toxic animals important – Know: symptoms, treatment, (chemical / mechanical / biological), seriousness & extent of wounds Toxic animals – Wide range of organisms (coast & inland areas) Emphasis on conspicuous & commonly encountered in central parts of S.A – Medically / Clinically important (impact on health) – Toxic (for survival & protection)

Toxic animals Ecologically important – man dependent on health of environment for survival Perceived to be dangerous – hence killed Eg. snakes, spiders, lizards Toxic in nature – hence used in hunting Toxin used – treatment of heart diseases, drugs, antivenoms Small portion of fauna endemic to Southern Africa – have to be conserved & preserved

Poison Defn.: Any substance in the environment or metabolic product of an organism which injures or kills the organism into which it is absorbed Refers to harmful environmental substances as well as metabolic products of organisms Not specifically indicating nor excluding involvement of organisms

Poison cont. Related terms: Poisoned – Has absorbed poison into the body Poisonous substance – substance poisonous (harmful) to other organisms

Poisonous animal Defn.: An animal that produces a poisonous substance or absorbs substances from the environment but does not have an appropriate apparatus for transferring poison to other organisms – Toxication during ingestion / intentional extraction

Toxin Defn: Any chemical substance which can damage the living body and specifically & restricted to substances of animal / plant origin Found inside bodies of organisms – Produced in special glands or during metabolic processes – acts as an antigen when entering the body & recognized by immune system

Toxic animal Defn: An animal which carries a toxin & is involved in the transfer of a toxic substance to other organisms

Related terms Toxic substance – poison / venom Toxication – act of transferring toxin or being toxicated Toxicated – have absorbed / to absorb toxin into the body Toxicator: – organism with a toxin in its body – Involved in transfer of toxic substance to other organisms Toxic animal cont.

Venom Defn: Poisonous fluid produced in venom glands of snakes, scorpions & spiders and introduced into victim by biting, stinging or spraying Mixture of toxic & non-toxic substances – Toxic substances – peptides, anhydrides, enzymes & proteins – Non-toxic substances – carriers of toxic substance

Venom cont. Related terms: Venenation / Envenomination – Process during which venom is transferred to victim Venom apparatus – Structure used for transferring venom by stinging, biting or spraying Venom canal – Used to transfer venom to victim – Eg. Solid venom claw, hollow vertebrate tooth

Venom cont. Venom claw – Arthropod claw for venom transfer Venom duct – Connects venom gland with venom apparatus Venom tube – Special epithelium-lined venom duct, conveys venom from venom gland Venom gland – For production of venom

Venomous animal Defn.: Produces a venom & has special apparatuses with which to project or insert the venom into the victim