Stonefish

It is actually a clay model of a fish with 13 wooden dorsal spines. The dancer experiences terrible agony, writhing on the ground. The whole ritual ends sadly with a death song. The fish involved in the dance is the stonefish, also a member of the scorpionfish family. It is believed to be the deadliest fish in the world. This is the most venomous fish known. It reaches up to 35 cm in length and lives in the Indo-Pacific region and northern Australian waters, from Brisbane to 600 km north of Perth. Stonefish may be found from exposed sand and mud in tidal inlets to depths of 40 m. Lying on the sea bed, it is perfectly camouflaged and looks exactly like an encrusted rock. It feeds on small fish and shrimps. When they swim by, the stonefish opens its mouth with lightning speed and gulps them down. The whole attack lasts for just 0,015 seconds.

Because the stonefish is vulnerable to attacks by bottom-feeding sharks and rays, it has found a way to defend itself- there is a row of 13 venomous spines along its back. In fact, the victim is the one who injures oneself. The stonefish is only dangerous if stepped on or caught. The thirteen dorsal spines project from venom glands along the back and venom is involuntarily expelled when pressure is exercised upon them. Then, a few weeks pass before the glands regenerate and recharge.

The sting causes excruciating pain and a tremendous swelling rapidly develops with death of tissues. The severity of the symptoms depends on the depth of penetration and the number of spines involved. The effects of the venom are muscle weakness, temporary paralysis and shock, which may result in death if not treated. Fatalities are known in the Indo-Pacific region but not in Australian waters.

One can prevent oneself from stonefish injury by wearing thick-soled shoes and treading very lightly- spines can piece through a shoe!

First Aid
At the beginning immersing the stung area into hot water may be effective, but hospitalization for intravenous narcotic analgesia, local anaesthetic infiltration or regional block may be required. Definitive management consists of administration of stonefish antivenom usually given intramuscularly.
Antivenom is administered if:
-the victim suffers from severe pain
-systematic symptoms like weakness and paralysis are observed
-there are multiple punctures, which indicate the discharge of several spines. This means that larger amount of venom has been injected.

source : http://library.thinkquest.org/C007974/2_1sto.htm

Blue-Ringed Octopus

Species:
There are two species of blue-ringed octopus:

1. Hapalochlaena lunulata, which is the larger and grows up to 20cm (8 in) across its stretched tentacles.

2. Hapalochlaena maculosa, is small and more common, weighing a mere 28 grams (1 oz). They are found in the shallow coral and rock pools of Australia.

While resting, the Blue Ring Octopus is a pale brown to yellow colour. The blue rings on its body only “light up” as a warning when the animal feels threatened.
Don’t pick one up – by the time you see the electric-blue rings, it’s too late!

Description:

It starts life the size of a pea and is fully grown at about the size of a golf ball.

They have a life span of approx. 2 years.

Carry enough poison to kill 26 adults within minutes.

Distribution:

Southern Western Australia, to southern Qld and northern Tasmania

Camouflage:

The Blue Ring Octopus is not an aggressive animal and when disturbed it flattens out its body to hide and changes its body colour to blend into its surroundings.

Body:

They are soft-bodied animals, with a sack-like body and eight arms covered with suckers.

Reproduction:

The female lays approximately 50 eggs in late Autumn. She carries her eggs around under her arms. Once the eggs have hatched after 3 – 6 months, the female dies. The young octopus develop rapidly, mature and mate early the following Autumn. The males then die and the female broods the eggs.

Diet:

The Blue Ring Octopus hunts during the day. It eats invertebrates and wounded fish.

General Information:

With a beak that can penetrate a wet-suit, they are one little cute creature to definitely look at BUT Don’t touch.

The bite might be painless, but this octopus injects a neuromuscular paralysing venom. The venom contains some maculotoxin, a poison more violent than any found on land animals. The nerve conduction is blocked and neuromuscular paralysis is followed by death. The victim might be saved if artificial respiration starts before marked cyanosis and hypotension develops. The blue-ringed octopus is the size of a golf ball but its poison is powerful enough to kill an adult human in minutes. There’s no known antidote. The only treatment is hours of heart massage and artificial respiration until the poison has worked its way out of your system.

The venom contains tetrodotoxin, which blocks sodium channels and causes motor paralysis and occasionally respiratory failure. Though with fixed dilated pupils, the senses of the patients are often intact. The victims are aware but unable to respond.

Although the painless bite can kill an adult, injuries have only occurred when an octopus has been picked out of its pool and provoked or stepped on.

SYMPTOMS

• Onset of nausea.

• Hazy Vision. ( Within seconds you are blind.)

• Loss of sense of touch, speech and the ability to swallow.

• Within 3 minutes, paralysis sets in and your body goes into respiratory arrest.

The poison is not injected but is contained in the octopus’s saliva, which comes from two glands each as big as its brain. Poison from the one is used on its main prey, crabs, and is relatively harmless to humans. Poison from the other gland serves as defense against predators. The blue-ringed octopus either secretes the poison in the vicinity of its prey, waits until it is immobile and then devours it, or it jumps out and envelops the prey in its 8 tentacles and bites it.

First Aid

First aid for blue-ringed octopus bites

Pressure-immobilization is a recommended first aid. Prolonged artificial respiration may also be required. May require supportive treatment including mechanical ventilation until the effects of the toxin disappear. There is no antivenin available in Australia.

Mouth to mouth resuscitation can keep the victim alive and the poison gradually wears off after 24 hrs, apparently leaving no side effects.

source : http://www.barrierreefaustralia.com/the-great-barrier-reef/blueringedoctopus.htm

Marbled Cone Snail

“Cone shells are marine snails and are found in reef environments throughout the world. They prey upon other marine organisms, immobilizing them with unique venom. There have been 30 recorded cases of human envenomation by fish-eating cone shells, in some cases fatal. Upon investigation it was found that toxins in cone shell venom possess pharmacological qualities that make them valuable tools in medical research.

In the dynamic marine environment in which cone shells reside, it has been necessary for these gastropods to develop an effective mechanism for immobilizing their otherwise speedy prey.The solution to the snail’s lack of physical agility has been the development of a highly potent concoction of neuronal toxins, which it uses to paralyze its prey (an especially vital factor for the fish eating species).

Cone shells can be classified according to their prey:
- Piscivorous–fish eaters
- Molluscivorous–mollusk eaters
- Vermivorous–worm eaters

Detection of the Prey
The cone shell detects prey in its environment using a “siphon” which bristles with chemoreceptors. It then extends its proboscis out towards the unfortunate target.

Conus lynceus Vietnam	Conus armadillo Phillipines
Conus textile Cloth of gold cone Queensland to N. of WA	Conus geographus Geographer cone Queensland to N. of WA
Conus tulipa Tulip cone Queensland	Conus marmoreus Marbled cone Queensland

Injection of the venom
The venom is produced in a long tubular duct that is often several times the length of the snail itself and at one end is attached to a muscular bulb which is thought to contract to provide the necessary force of venom injection through the ‘tooth’. Hollow spear-like radular teeth, which are made in the ‘radular sac’ and filled with venom, are transported through the ‘buccal cavity’ to the tip of the proboscis where they are retained by radular muscle. Upon contact with the prey, the proboscis impales the harpoon like tooth into any exposed tissue and injects the venom through this. The harpoon is attached to the gastropod via a ‘thread’ so that the prey is actually tethered to the snail (although the organism is often paralyzed within one or two seconds, leaving little opportunity to escape). Once the prey is paralyzed, the gastropod retracts the cord by which the prey is attached and engulfs the prey through it’s the radular opening of it’s proboscis and into its distensible stomach where it is digested. The cone shell can reload further teeth from the radular sac for multiple envenomation by retracting the proboscis into the radular sac and grasping another tooth with the radular muscle.

Composition of the Venom
The composition of the venom differs greatly between species and between individual snails within each species, each optimally evolved to paralyze its prey. The active components of the venom are small peptides toxins, typically 12-30 amino acid residues in length and are highly constrained peptides due to their high density of disulfide bonds.

The composition of the venom is different with each injection. The pharmacological activity also changes, the venom containing lethal and paralytic neurotoxic peptides as well as components which elicit specific and varied physiological and behavioral responses when tested in mice, from shaking to depression! The paralysis of the prey by the killer-snail venom permits correct presentation of the prey to the gastropod so that it engulfed and enzymatically digested by the killer snail’s distensible stomach.

The paralytic components of the venom that have been the focus of recent investigation are the alpha-, omega- and mu-conotoxins. All of these conotoxins act by preventing neuronal communication, but each targets a different aspect of the process to achieve this. The alpha-conotoxins target nicotinic ligand gated channels, the mu-conotoxins target the voltage-gated sodium channels and the omega-conotoxins target the voltage-gated calcium channels.”

First aid for Cone shell stings
The venom of these creatures contains a number of neurotoxic peptides that cause weakness and loss of coordination. The victim’s vision, speech and hearing are disturbed. Nausea and general pruritis are some of the less common symptoms. Numbness, local pain and swelling may also occur. In cases of severe envenomation, respiratory muscle paralysis may lead to death. Pressure-immobilization should be used and, if necessary, assisted ventilation. There is no antivenom developed for cone snail stings. Because the wound can be contaminated, tetanus prophylaxis should be performed.

source : http://library.thinkquest.org/C007974/2_1con.htm