The document discusses various marine toxins and venomous creatures. It describes the blue-ringed octopus which has a venomous bite from its saliva containing tetrodotoxin (TTX). Sea snakes and sea urchins also have venomous bites or stings. The stonefish has venomous spines that can cause excruciating pain and paralysis. The crown-of-thorns starfish and various cone snail species release toxins from their spines or radula that cause pain, swelling, and in rare cases death. Box jellyfish and pufferfish contain TTX which is lethal and has claimed many lives. Conotoxins from cone snails are peptides that block ion channels and receptors
Most of the world's snakes are what are referred to as clinically non-venomous. This means they do not produce a toxin that is clinically significant to people.
Phylum Platyhelminthes
Class Turbellaria
Class Monogenea
Class Trematoda
Class Cestoidea
Characteristics
Reproduction and Development
Presentation
Best of Luck
Most of the world's snakes are what are referred to as clinically non-venomous. This means they do not produce a toxin that is clinically significant to people.
Phylum Platyhelminthes
Class Turbellaria
Class Monogenea
Class Trematoda
Class Cestoidea
Characteristics
Reproduction and Development
Presentation
Best of Luck
Introduction
Gnathostomata are the jawed vertebrates. (gnathos= "jaw" + (stoma)="mouth".
It comprises roughly 60,000 species. (99% of all living vertebrates).
Living gnathostomes have teeth, and paired appendages.
A horizontal semicircular canal is present in the inner ear.
Myelin sheaths is present on the neurons.
Adaptive immune system uses V(D) J recombination ( it is the mechanism of somatic recombination that occurs only in developing lymphocytes during the early stages of T and B cell maturation. VDJ recombination is the process by which T cells and B cells randomly assemble different gene segments – known as variable (V), diversity (D) and joining (J) genes – in order to generate unique receptors (known as antigen receptors) that can collectively recognize many different types of molecule. While Agnatha (petromyzon and hagfish) use genetic recombination in the variable lymphocyte receptor gene.
It is now assumed that Gnathostomata evolved from ancestors that already possessed a pair of both pectoral and pelvic fins.
In addition to this, some placoderms were shown to have a third pair of paired appendages, that had been modified to claspers in males and basal plates in females—a pattern not seen in any other vertebrate group.
It is believed that the jaws evolved from anterior gill support arches that had acquired a new role, being modified to pump water over the gills by opening and closing the mouth more effectively – the buccal pump mechanism.
Presence of Calcified, bony skull and vertebra are the characteristic features of Gnathostomata (fishes, amphibians, reptiles, birds and mammals).
Pelvic fins are situated just in front of the anus.
Interventrals and basiventrals present in the backbone. These are the elements of the backbone which lie under the notochord, and match the basidorsals and interdorsals respectively.
Gill arches which lie internally to the gills and branchial blood vessels, contrary to the gill arches of all jawless craniates, which are external to the gills and blood vessels.
A horizontal semicircular canal in the inner ear.
Paired nasal sacs which are independent from the hypophysial tube.
There are numerous other characteristics of the soft anatomy and physiology (e.g. myelinated nerve fibres, sperms passing through urinary ducts, etc.), which are unique to the gnathostomes among extant craniates, but cannot by observed in fossils.
Snake, common name for an elongated, limbless reptile of the order Squamata, which also includes the x lizards . Most snakes live on the ground, but some are burrowers, arboreal, or aquatic; one group is exclusively marine. In temperate climates they hibernate. They are generally solitary in their habits, although they may congregate in places offering food or shelter, and large numbers may hibernate together. Snakes range in length from about 4 in. (10 cm) to over 30 ft (9 m).
In most snakes limbs are entirely lacking, but a few have traces of hind limbs. The skin, which is covered with horny scales, is shed, usually several times a year. The extremely long, narrow body is associated with distinctive internal features. The number of vertebrae is much larger than in most vertebrates, paired internal organs are arranged linearly rather than side by side, and only one lung is developed, except in members of the boa family, which have two lungs.
Presented By- Aseem Madhur, Juhi Ranjan, Shalini Jalan, Shreya Podder.
Introduction The Gastropods - Phylum Mollusca - Second largest class.
Includes - sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs.
The most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species.
Older classification of the gastropods
Opisthobranchia (gills to the right and behind the heart).
Gymnomorpha (no shell).
Prosobranchia (gills in front of the heart).
Pulmonata (with a lung instead of gills).
"Understanding the Carbon Cycle: Processes, Human Impacts, and Strategies for...MMariSelvam4
The carbon cycle is a critical component of Earth's environmental system, governing the movement and transformation of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms. This complex cycle involves several key processes such as photosynthesis, respiration, decomposition, and carbon sequestration, each contributing to the regulation of carbon levels on the planet.
Human activities, particularly fossil fuel combustion and deforestation, have significantly altered the natural carbon cycle, leading to increased atmospheric carbon dioxide concentrations and driving climate change. Understanding the intricacies of the carbon cycle is essential for assessing the impacts of these changes and developing effective mitigation strategies.
By studying the carbon cycle, scientists can identify carbon sources and sinks, measure carbon fluxes, and predict future trends. This knowledge is crucial for crafting policies aimed at reducing carbon emissions, enhancing carbon storage, and promoting sustainable practices. The carbon cycle's interplay with climate systems, ecosystems, and human activities underscores its importance in maintaining a stable and healthy planet.
In-depth exploration of the carbon cycle reveals the delicate balance required to sustain life and the urgent need to address anthropogenic influences. Through research, education, and policy, we can work towards restoring equilibrium in the carbon cycle and ensuring a sustainable future for generations to come.
Introduction
Gnathostomata are the jawed vertebrates. (gnathos= "jaw" + (stoma)="mouth".
It comprises roughly 60,000 species. (99% of all living vertebrates).
Living gnathostomes have teeth, and paired appendages.
A horizontal semicircular canal is present in the inner ear.
Myelin sheaths is present on the neurons.
Adaptive immune system uses V(D) J recombination ( it is the mechanism of somatic recombination that occurs only in developing lymphocytes during the early stages of T and B cell maturation. VDJ recombination is the process by which T cells and B cells randomly assemble different gene segments – known as variable (V), diversity (D) and joining (J) genes – in order to generate unique receptors (known as antigen receptors) that can collectively recognize many different types of molecule. While Agnatha (petromyzon and hagfish) use genetic recombination in the variable lymphocyte receptor gene.
It is now assumed that Gnathostomata evolved from ancestors that already possessed a pair of both pectoral and pelvic fins.
In addition to this, some placoderms were shown to have a third pair of paired appendages, that had been modified to claspers in males and basal plates in females—a pattern not seen in any other vertebrate group.
It is believed that the jaws evolved from anterior gill support arches that had acquired a new role, being modified to pump water over the gills by opening and closing the mouth more effectively – the buccal pump mechanism.
Presence of Calcified, bony skull and vertebra are the characteristic features of Gnathostomata (fishes, amphibians, reptiles, birds and mammals).
Pelvic fins are situated just in front of the anus.
Interventrals and basiventrals present in the backbone. These are the elements of the backbone which lie under the notochord, and match the basidorsals and interdorsals respectively.
Gill arches which lie internally to the gills and branchial blood vessels, contrary to the gill arches of all jawless craniates, which are external to the gills and blood vessels.
A horizontal semicircular canal in the inner ear.
Paired nasal sacs which are independent from the hypophysial tube.
There are numerous other characteristics of the soft anatomy and physiology (e.g. myelinated nerve fibres, sperms passing through urinary ducts, etc.), which are unique to the gnathostomes among extant craniates, but cannot by observed in fossils.
Snake, common name for an elongated, limbless reptile of the order Squamata, which also includes the x lizards . Most snakes live on the ground, but some are burrowers, arboreal, or aquatic; one group is exclusively marine. In temperate climates they hibernate. They are generally solitary in their habits, although they may congregate in places offering food or shelter, and large numbers may hibernate together. Snakes range in length from about 4 in. (10 cm) to over 30 ft (9 m).
In most snakes limbs are entirely lacking, but a few have traces of hind limbs. The skin, which is covered with horny scales, is shed, usually several times a year. The extremely long, narrow body is associated with distinctive internal features. The number of vertebrae is much larger than in most vertebrates, paired internal organs are arranged linearly rather than side by side, and only one lung is developed, except in members of the boa family, which have two lungs.
Presented By- Aseem Madhur, Juhi Ranjan, Shalini Jalan, Shreya Podder.
Introduction The Gastropods - Phylum Mollusca - Second largest class.
Includes - sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs.
The most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species.
Older classification of the gastropods
Opisthobranchia (gills to the right and behind the heart).
Gymnomorpha (no shell).
Prosobranchia (gills in front of the heart).
Pulmonata (with a lung instead of gills).
"Understanding the Carbon Cycle: Processes, Human Impacts, and Strategies for...MMariSelvam4
The carbon cycle is a critical component of Earth's environmental system, governing the movement and transformation of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms. This complex cycle involves several key processes such as photosynthesis, respiration, decomposition, and carbon sequestration, each contributing to the regulation of carbon levels on the planet.
Human activities, particularly fossil fuel combustion and deforestation, have significantly altered the natural carbon cycle, leading to increased atmospheric carbon dioxide concentrations and driving climate change. Understanding the intricacies of the carbon cycle is essential for assessing the impacts of these changes and developing effective mitigation strategies.
By studying the carbon cycle, scientists can identify carbon sources and sinks, measure carbon fluxes, and predict future trends. This knowledge is crucial for crafting policies aimed at reducing carbon emissions, enhancing carbon storage, and promoting sustainable practices. The carbon cycle's interplay with climate systems, ecosystems, and human activities underscores its importance in maintaining a stable and healthy planet.
In-depth exploration of the carbon cycle reveals the delicate balance required to sustain life and the urgent need to address anthropogenic influences. Through research, education, and policy, we can work towards restoring equilibrium in the carbon cycle and ensuring a sustainable future for generations to come.
Willie Nelson Net Worth: A Journey Through Music, Movies, and Business Venturesgreendigital
Willie Nelson is a name that resonates within the world of music and entertainment. Known for his unique voice, and masterful guitar skills. and an extraordinary career spanning several decades. Nelson has become a legend in the country music scene. But, his influence extends far beyond the realm of music. with ventures in acting, writing, activism, and business. This comprehensive article delves into Willie Nelson net worth. exploring the various facets of his career that have contributed to his large fortune.
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Introduction
Willie Nelson net worth is a testament to his enduring influence and success in many fields. Born on April 29, 1933, in Abbott, Texas. Nelson's journey from a humble beginning to becoming one of the most iconic figures in American music is nothing short of inspirational. His net worth, which estimated to be around $25 million as of 2024. reflects a career that is as diverse as it is prolific.
Early Life and Musical Beginnings
Humble Origins
Willie Hugh Nelson was born during the Great Depression. a time of significant economic hardship in the United States. Raised by his grandparents. Nelson found solace and inspiration in music from an early age. His grandmother taught him to play the guitar. setting the stage for what would become an illustrious career.
First Steps in Music
Nelson's initial foray into the music industry was fraught with challenges. He moved to Nashville, Tennessee, to pursue his dreams, but success did not come . Working as a songwriter, Nelson penned hits for other artists. which helped him gain a foothold in the competitive music scene. His songwriting skills contributed to his early earnings. laying the foundation for his net worth.
Rise to Stardom
Breakthrough Albums
The 1970s marked a turning point in Willie Nelson's career. His albums "Shotgun Willie" (1973), "Red Headed Stranger" (1975). and "Stardust" (1978) received critical acclaim and commercial success. These albums not only solidified his position in the country music genre. but also introduced his music to a broader audience. The success of these albums played a crucial role in boosting Willie Nelson net worth.
Iconic Songs
Willie Nelson net worth is also attributed to his extensive catalog of hit songs. Tracks like "Blue Eyes Crying in the Rain," "On the Road Again," and "Always on My Mind" have become timeless classics. These songs have not only earned Nelson large royalties but have also ensured his continued relevance in the music industry.
Acting and Film Career
Hollywood Ventures
In addition to his music career, Willie Nelson has also made a mark in Hollywood. His distinctive personality and on-screen presence have landed him roles in several films and television shows. Notable appearances include roles in "The Electric Horseman" (1979), "Honeysuckle Rose" (1980), and "Barbarosa" (1982). These acting gigs have added a significant amount to Willie Nelson net worth.
Television Appearances
Nelson's char
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
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and write to us if you have any questions:
info@kuddlelife.org
Natural farming @ Dr. Siddhartha S. Jena.pptxsidjena70
A brief about organic farming/ Natural farming/ Zero budget natural farming/ Subash Palekar Natural farming which keeps us and environment safe and healthy. Next gen Agricultural practices of chemical free farming.
UNDERSTANDING WHAT GREEN WASHING IS!.pdfJulietMogola
Many companies today use green washing to lure the public into thinking they are conserving the environment but in real sense they are doing more harm. There have been such several cases from very big companies here in Kenya and also globally. This ranges from various sectors from manufacturing and goes to consumer products. Educating people on greenwashing will enable people to make better choices based on their analysis and not on what they see on marketing sites.
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
2. Unit – 2 - Venomous Bites
This golf ball-sized octopus is
small, about 7 cm long, shy
and hides in coral crevices or
under rocks.
It may look cute, harmless and
attractive but is amongst the
most dangerous creatures on the
planet. Its venomous bite has
claimed a number of human
lives as its saliva contains TTX.
Blue ringed Octopus
3. Sea Snakes
Sea snakes are reptiles, have
scales and flattened, paddle-
like tails with heads that
resemble land snakes whereas
eels are fishes, have a fish-like
face and mouth as well as one
long continuous dorsal fin.
All sea snakes are highly
venomous and should not be
handled even though they are
shy, gentle and do not normally
pose a threat unless provoked.
4. Venomous spines
The family of fishes known
as Scorpaenidae include
lionfish, scorpion fish
and stonefish.
They have venomous
spines on their dorsal
fins as a defence against
rays and sharks.
Scorpion fish
5. Stone fish
The stonefish, the most venomous
fish in the world, looks like
encrusted rock or dead coral.
Most human victims injure
themselves when they
accidentally step on it or place
their hands on it.
13 hard spines on its back, sharp
enough to puncture rubber soled
shoes, carry neurotoxic venom
into the wound when the spines
are pressed, causing
excruciating pain, temporary
paralysis and shock, and in rare
cases, even death (only 3
fatalities from stonefish
envenomation has ever been
recorded).
6. Star fish – Crown of thorns
The Crown of Thorns
starfish Acanthaster planci is the
only venomous starfish. It can
grow up to a metre in diameter
and can have as many as 21
arms.
It is covered with sharp spines all
over its body except on its
underside. Spines can grow up to
6 cm in length and can easily
penetrate a wetsuit. On contact,
the spines release a variety of
toxins which although not fatal,
are painful, causes redness and
local swelling.
7. Sea Urchin
Venomous urchins like fire
urchins (Asthenosoma
species) and long-spined
urchins (Diadema species)
deliver their venom through
their spines while flower
urchins (Toxopneustes
pileolus) deliver venom
through jaw-like organs
called Pedicellaria supported
on stalks and surrounded by
non-venomous spines.
8. Venomous stings
Cone shells are highly sought
after by shell collectors due
to their attractive and
intricate markings.
The venom is contained in the
tongue-like proboscis
(radula) equipped with
harpoon-shaped teeth.
About 30 recorded fatalities
from cone shell stings, most
of them from the Conus
geographus species.
Cone shells
9. Sting rays
Stingrays are shy and
frequently hide in shallow
waters under rocks or buried
under the sand with only
their eyes slightly exposed.
The front half of the tail may
have up to 7 barbs or
spines located on the top
side which the ray can use
to inflict a painful,
venomous sting to any
aggressor by whipping its
tail upwards in an arc, much
like the way a scorpion
stings.
10. Box Jelly fish
The box jelly Chironex
fleckeri is the world's most
venomous jellyfish and
possibly the world's most
venomous creature, causing
about 70 fatalities just in
Australia, and between 20-
40 deaths annually in the
Philippines. It is found
mainly in the northern
coastal waters of Australia
and in some parts of the
Indo-Pacific.
11. Puffer fish
The pufferfish is so poisonous
that contains TTX in the
body.
There are over 120 species of
puffer fish in the world and
unfortunately most are
dangerous so it’s best to
avoid them.
Consumption
15. • Potent neurotoxin
• Named after fish Tetraodontiformes = “four toothed”
or Tetrodon Pufferfish
• Family Tetraodontidae and Diodontidae
• In Japan – Fugu poison
• Non protein and colourless crystals
• Chemical name – Amino Perhydroquinazoline
• Formula C11 H17 N3 O8
• Identified from California Newt, Salamander, Parrotfish,
Starfish, Frogs of the genus Atelopus, Blue-ringed Octopus,
Xanthid Crabs, Boxfish, Horseshoe crabs, Marine Snails.
16. • Binds to site of voltage gated Na+ channels; where it
binds and blocking the passage of Na+ ions into the
nerve cell.
• It blocks the Na+ current in human hearts and
prevents contraction.
• Virtually insoluble in all organic solvents but soluble
in acidic media.
• 3 nitrogen atoms of tetrodotoxin are present in the
molecule as a guanidine moiety.
• 10,000 times more lethal than cyanide.
• LD50 – 5.0 – 8.0 g/kg.
17. Controversies on production of TTX
• 1. TTX is produced by the associated bacteria
lives inside the pufferfish.
• 2. It is secreted by the fish itself.
• Bacteria like – Vibrionaceae family,
Pseudomonas tetraodonis, Photobacterium
phosphoreum.
• TTX found in liver, ovary, muscle and skin.
18. Intoxication
• Intoxication of TTX is characterised by rapid onset
of weakness, dizziness; paresthesia in the lips,
tongue and throat.
• In extremities, nausea and occasionally vomiting
occur.
• In more severe cases, include sweating, salivation,
muscular weakness, respiratory distress.
• In very severe cases, muscular paralysis and death
due to apparent respiratory paralysis occur 6-24 hrs
following ingestion of the toxic fish.
• Cysteine is reported to react with TTX (by binding)
in in vitro at pH 7.0 and produce a non-toxic
substance.
19. Pharmacological potency of TTX
• The initial action of TTX is blocking the Na+
channel of muscle and nerve block.
• Direct blocking action in the muscle fibers is
usually longer than the nerve block.
• Toxin found in highest conc. in kidney & heart
and lowest in brain & blood after 20 min. s.c.
administration of toxin in rat.
• TTX has proved to be a useful tool of the
analysis of events, which occurs in the nerve,
result in impulse propagation.
20. • A good hypertensive agent & produces fall of
blood pressure of the cat in the doses of 2-3 g/kg
in i.v.
• Also a potent respiratory inhibitor at very low
doses (0.5-3 g/kg ) to arrest the respiration.
• TTX inhibit the stimulation of respiration &
metabolism in preparations of in vitro guinea pig
brain.
• Clinically used as a pain relieving compound, in
the cases of patients suffering from the
neurogenic form of Hansen’s disease (Leprosy).
21. Natural defense
• Puffer fishes swims very slow, therefore
comparatively easy targets for predators.
• As a defense mechanism, puffers have the
ability to inflate rapidly, filling their extremely
elastic stomachs with water.
22. Sensitivity
• TTX-R and TTX-S on VG sodium channels (out
of 9 VGNC, 6 are TTX-S and 3 for TTX-R)
• Binds at site-1 of (VGSC) Na+ channel
• Very less effect on cardiac sodium channels
than nerve and muscle Na+ channels
23. Clinical trials – Pain relief for Cancer
Patients
• 15-90g of TTX administered intramuscularly
for four days; 17 out of 31 cancer patients
reported pain reduction.
• Significant analgesic effect also observed in
another study.
• 30 g of TTX administered subcutaneously
twice daily for 4 days; 21 out of 41 cancer
patients reported pain relief.
26. Conotoxin
• Conotoxin - a group of Neurotoxic peptide from
the venom of marine snail – Genus Conus.
Tropical seas in worldwide including California
and South Africa.
• Peptide contains 10-40 amino acids.
• Rich in Cysteine amino acid residues (1 or
above) – disulphide bridges.
• Blocking the neuromuscular system of the prey,
which may be fish, mollusc or marine worm.
• LD50 of conotoxin varies species to species.
27. • Piscivores, Molluscivores and Vermivores.
• Most dangerous animal to humans are the fish
hunting Conus sp., particularly Conus
geographus.
• Reportedly 20 human fatalities were identified,
due to careless handling of divers and shell
collectors.
• Sting by radula.
• Sting includes, numbness at the site of stinging
which spreads to upper parts of the limb and to
rest of the body.
• Blurring of vision, impaired speech and muscle
paralysis precede to death.
30. • In rats & guinea pigs showed marked
respiratory depression and resp.failure
accompanied by blood pressure fluctuations
upon i.v. injection of venom of C. geographus.
• LD50 of freeze dried C. geographus venom in
mice was 0.82 mg/kg on i.v. injection & 1.3
mg/kg upon i.p. injection.
• Approximately 700 sp. of cone snails recorded
and all are Carnivores.
31. • They are nocturnal hunters.
• C. geographus, C. catus, C. aulicus,
C.gloriamaris, C. omaria, C. magus, C.striatus,
C. tulipa, C. textile.
• C. geographus is most dangerous to humans.
• Piscivores are having stronger toxin than
molluscivores and vermivores; it shows that due
to highly movable fish to be hunted by stronger
toxin.
• No specific antidote available for conotoxin
sting.
• Molluscivores like C.textile, C.regius are mollusc
eater and hazardous to humans.
32. Types of Conotoxin
Type of
Conotoxin
Site of
action
Details Species
Alpha Nicotinic
Ach
receptors
Inhibits nicotinic acetylcholine receptors at nerves and
muscles. The result is paralysis.
Conus magus
C. geographus
Gamm
a
Ion
channel
inhibitor
Gamma-conotoxins may act on voltage-gated non-
specific cation pacemaker channels (HCN). Triggers
depolarization and firing of action potential bursts in the
caudodorsal neurons of lymnaea.
C. geographus
C. textile
C. consors
C. magus
Delta Na
channel
Inhibits the inactivation of voltage dependent sodium
channels (“delta” slows the inactivation of the sodium
channel, “mu” inhibits the sodium channel)
C. striatus
C. purpurascens
C. textile
Epsilon Ca
channel
Epsilon-conotoxins act at presynaptic membranes,
blocking the calcium channels or G protein-coupled
receptors.
C. textile
Iota Na
channel
Iota-conotoxins bind to voltage-gated sodium channels
(Nav) and act as agonists by shifting the voltage-
dependence of activation to more hyperpolarized
levels.
C. litteratus
C. striatus
C. radiatus
Kappa K channel Inhibits voltage-graded potassium channels, resulting in
tremors.
C. betulinus
C. striatus
C. radiatus
33. Type of
Conotoxin
Site of action Details Species
Mu Na channel Inhibits voltage-graded sodium channels in muscles.
The mechanism is similar to that of saxitoxin produced
from red tide algae.
C. geographus
C. tulipa
C. striatus
Rho Alpha adrenal
receptors
Allosteric inhibitor of alpha-1B adrenergic receptors
(ADRA1B). Binds to an allosteric modulatory site on
transmembrane helix 6 and 7 at the base of extracellular
loop 3 of ADRA1B.
C. tulipa
Sigma Affects serotonin
activity
Sigma-conotoxins bind and inhibit serotonin-gated ion
channels.
C. geographus
Chi Neuronal adrenergic
transporter
Chi-conotoxins inhibit the neuronal noradrenaline
transporter.
C. marmoreus
Omega Ca channel Affects the calcium channels associated with nerve
impulse transmission at the neuromuscular junction.
Calcium channels are related to sensitivity to pain.
C. geographus
C. textile
C. striatus
Conantokins NMDA receptors Blocks nerve impulses that use glutamic acid rather than
acetylcholine as the neurotransmitter.
C. geographus
Conopressin
s
Modulate
Vasopressin /
Oxytocin receptors
(Increases blood
pressure)
Targets vasopressin-oxytocin related receptors. C. textile
35. Clinical symptoms
Non Fatal Case (full recovery) Fatal Cases
Burning pain Numbness without pain (some species
produce severe pain and spreading
numbness)
Swollen arm and pain Lips become stiff
Local numbness spreading rapidly to
involve the entire body, with some
cardiac and respiratory distress
Blurred vision
Progressive weakness, loss of
coordination, drooping eyelids,
shallow breathing
Paralysis
Headache, nausea, stomach cramps,
shortness of breath
Coma
These symptoms occur almost
immediately upon injection
Death occurs as the result of respiratory
and/or cardiovascular collapse.
36. Pharmacology of Conotoxins
• Estimated 50,000 – 1,00,000 conotoxins,
approximately 0.1% have been characterised
pharmacologically.
• Important tool for defining ion channels function
(Neurobiologists).
• Studies found that C.geographus cause
convulsions and resp. suppression in mice.
• Conotoxins target and block potently a wide
range of ion channels, such as voltage-gated
sodium channels (Nav), voltage-gated calcium
channels (Cav), voltage-gated potassium
channels (Kv), nicotinic acetylcholine receptor
(nAchRs) and NMDA (N-methyl D-aspartate)
receptor.
38. • LD50 of α – conotoxin is 10-100g/kg in mice
but hydrogen cyanide is 1-3 mg/kg.
• Acetylcholine (Ach) is released by a motor
neuron and it attaches to the nicotinic receptors
on the muscle and then the muscle starts to
contract.
• Physically blocking the nicotinic receptor with a
drug or toxin would stop the contraction and
cause paralysis.
• The first isolated -conotoxin were named as
GI, GIA and GII found in C.geographus, it does
not affect the CNS.
39. • Inhalation of α – conotoxin is similar to the
inhalation of botulism toxin.
• Muscle paralysis by blocking ion channels in
muscle found from C.purpurascens, is
piscivore; causes both flacid paralysis &
‘Sudden tetanus on its prey’ named as PIVA
& -conotoxin PIIIA to paralyse its fish prey.
• conotoxin of piscivores inactivate Na
channel in mammals. Nav channel is necessary
for normal electrical functioning.
42. Classes
Delta
-inhibits the inactivation of
voltage-dependent Na
channels.
-Hyperactivity, epilepsy
-keeping sodium channels
open and interfering with
action potential
propagation
43. Classes
Kappa
-inhibits K channels
-Preventing potassium
efflux , disrupting resting
potentials
-Treatment of
Neurodegenerative
disorders
47. Ziconotide
• 1st drug of marine origin which obtained approval by the
USFDA on December 31st 2004.
• Isolated from C.magus of -conotoxin MVIIA for under the
brand name of ‘Prialt’, commercial drug in USA and E.U.
• Treating Parkinson’s Alzheimer’s diseases.
• Blocks the N-Type calcium channels on the primary
nociceptive nerves in the spinal cord.
48. • Used only for “management of severe chronic pain”
• Approved for the treatment of chronic pain as a morphine
replacement therapy.
• It is the most powerful painkiller known to date.
• Must be administered intrathecally.
• Common side effects: dizziness, nausea, confusion &
headache.
• Rare side effects: hallucinations, suicidal thoughts, new or
worsening depression, meningitis and seizures.
51. Ciguateratoxin
• Most commonly reported fish poisoning or
Seafood poisoning.
• Caused by bioaccumulation of toxins produced
by Gambierdiscus toxicus (Dinoflagellate) in
large reef fish –e.g. barracuda, grouper, snapper,
sea bass.
• Toxins accumulate in greater quantities in the
flesh of bigger fishes and enter human organism
after consumption of these fishes.
• 20,000-50,000 cases worldwide annually –Est’d
1600/yr in USA – In some countries as high as
1200 per 1,00,000.
• Symptoms of Ciguateratoxin are the reversal of
thermal sensation called “Dry Ice Sensation”.
52. • Outbreaks associated with wholesale of imported
fish.
• Hawaii and Florida report 90% of all cases.
• Ciguatera fish poisoning (CFP) is most frequent
in Caribbean, Indian Ocean, Maldives,
Seychelles, Solomon islands, Guam islands,
Fortuna islands, Williams islands etc.
• CFP reported for the first time in 1601 in Indian
Ocean.
• The fishes that are connected to this poisoning are
more than 420 kinds. They are so called vector
fishes genus Herbivores and Carnivores.
54. • Ciguatoxins (CTXs) are neurotoxins. They are
lipid soluble polyether compounds made up of
13 or 14 rings fused into rigid ladder-like
structures.
• The Pacific ciguatoxin-1 (P-CTX-1) is the
most potent and its structure is slightly
different from that of the Caribbean
ciguatoxin-1 (C-CTX-1).
• LD50 of C-CTX-1 for guinea pigs
intraperitoneally is 0.45 ng/kg. A dose of 0.1
ng causes intoxication in humans. The toxin is
lipid soluble - accumulated and stored in the
flesh of fishes.
55. Symptoms
• The initial symptoms appear between the 4th
and the 12th hour (on the average 12 hours)
after the consumption of fish with preserved
taste qualities. Three main clinical syndromes
develop: gastrointestinal, neurologic and
cardiocirculatory. The first complaints are from
abdominal pain, nausea and vomiting.
• Cardiotoxicity include: cardiac bradycardia,
arrhythmias or cardiac block appear. The
intensity and duration of symptoms are
different in different individuals and regions,
where the poisoning had taken place.
56. • Lethal cases were reported with frequency from
0.1% to 12%. The lethal exit is associated to
consumption of the most toxic parts of the fish
– liver, other internal organs.
• Cases of ciguatera poisoning have been
described in a newborn baby and a breast – fed
baby, because the lipid soluble ciguatoxin can
pass through placental barrier and mother‘s
milk.
59. Mechanism of Ciguateratoxin
• The mechanism of action of ciguatoxins is related
to its direct effect on excitable membranes.
Ciguatoxins are characterized by their affinity
binding to voltage sensitive sodium channels,
causing them to open at normal cell resting
membrane potentials.
• This results in an influx of Na+ ions, cell
depolarization and the appearance of spontaneous
action potentials in excitable cells. As a
consequence of the increased Na+ permeability,
the plasma membrane is unable to maintain the
internal environment of cells and volume control.
This results in alteration of bioenergetic
mechanisms, cell and mitochondrial swelling and
bleb formation on cell surfaces.
60. • In myocardium, when ciguatoxin affects
voltage-dependent Na+ channels, causing Na+ to
move intracellularly, normal cellular
mechanisms begin to extrude sodium and take
up calcium.
• Calcium is the intracellular trigger for muscle
contraction. Although much of the increased
calcium is buffered by the sarcoplasmic
reticulum, it is likely that locally increased
calcium concentrations increase the force of
cardiac muscle contraction.
61. Pharmacokinetics
• Ciguatoxins are fat soluble and absorption
from the gut is rapid and substantial, although
an early onset of vomiting and diarrhoea
may exist in expelling some of the toxins
before they are absorbed.
• Since cleaning ciguateric fish can cause
tingling of the hands and eating them can
cause altered sensation in the oral cavity and
dysphagia, it would appear that ciguateratoxins
can penetrate the skin and mucous membranes.
63. CIGUATERA (3009 Cases)
Frequency of Signs and Symptoms
Sign or Symptom Percentage
Paresthesias (extremities) 89.2
Paresthesias (circumoral) 89.1
Temperature reversal 87.6+
Arthalgia 87.5
Myalgia 81.5
Diarrhea 70.6
Headache 59.2
Chills 59
Abdominal Pain 46.5
Pruritus 44.9
Nausea 42.9
Vertigo 42.3
Ataxia 37.7
64. • Many species and many families of reef fishes are
involved in ciguatera globally. These include the
herbivorous Acanthuridae and
corallivorous Scaridae (parrot fish), which are
considered key vectors in the transfer of ciguatoxins
to carnivorous fish.
• Species of carnivorous fish cause ciguatera, includes
Muraenidae (moray eels) and Lutjanidae (snappers
such as red bass) which are notorious in the Pacific,
Serranidae (groupers) including coral trout from the
Great Barrier Reef, Epinephelidae, Lethrinidae,
Scombridae (mackerel), Carrangidae (jacks)
and Sphyraenidae (barracudas). The latter two
families are a particular problem in the Caribbean.
72. Treatment
• There is no specific antidote.
• The most important is Mannitol therapy for
two primary goals: reduction of acute
symptoms (especially neurologic) and possible
prevention of chronic neurologic symptoms. It
is a diuretic may increase the urine output.
• I.V. Mannitol administered at 0.5 to 1.0 g/kg
body weight over a 30-45 minute period. It is
suggested that to be given within 48-72 hours
of ingestion of toxic fish, although beneficial
effects have been observed even up to several
weeks after intoxication.
73. Prevention
• Prevention requires educating people to the
risk of eating coral reef fish such as
barracuda, grouper, snapper, amberjack, and
surgeonfish that are caught in areas known to
be contaminated, such as the waters off
Pacific, south Florida and the Caribbean.
• Because the toxins are colorless, odorless,
and tasteless and are not destroyed by
cooking, they are difficult to detect.
