2. Tremendous and Venomous



Slither, swim, and crawl into the world of venomous animals. These chemical masterminds have evolved some of the coolest ways to survive in their habitats. Find out all about how the fangs, spines, and barbs make them all tremendous!


What did we do today?

-Learned the difference between venomous and poisonous animals

-Searched the aquarium for venomous and poisonous animals

-Used what we learned and solved the mystery of the unknown patient

-brainstormed new ways to stop invasive lionfish populations

Questions to ask your Junior Biologist

Are all venomous animals dangerous? Depends. If you see a venomous animal or know they’re nearby, stay away! Observe from a distance and leave them alone, venomous animals won’t intentionally attack you if you are respecting them.

Should you pee on a jelly sting? This one is a common myth, but this idea has been debunked. The best thing to do is to remain calm, and pour vinegar on the wound or heat it.

Are all venomous animals flashy? Nope! While some animals advertise their venom with bright colours, some prefer to stay hidden. Animals like the scorpionfish or cone snails can be well hidden!

Why are lionfish causing so much damage to Atlantic reefs?  They eat a lot of young fish, preventing local species from maturing. Their venomous spines are deterrents to predators. To top it all off, lionfish can lay up to 2 million eggs a year!

What can I do about invasive species? If you get the chance, eat lionfish! It’s helping lower invasive populations. Other things include not releasing pets into local habitats and participating in invasive species removals!

Let’s see what’s so tremendous!

First things first, a question that you might have is what’s the difference between poisonous animals and venomous animals. The difference is simply the method of delivery. Both poisons and venom are highly specialized compounds designed to harm or kill the victim. Venom are injected into the victim. Think of snake bites, lionfish spines, and stingray barbs. Poisonous animals are ones that need to be ingested, inhaled, or absorbed before delivering their poisons. Think poison dart frogs, poison berries, and poison ivy.

Poisonous vs Venomous-Snake Buddies

How does venom work? There are three main types of venom used by animals like snakes. Let’s count them down!

  1.  Hemotoxins. Hemo means blood, so this class of venom are blood toxins. They are amazing chemical compounds that affect the blood. Some cause drops in blood pressure, some affect red blood cells, and others will cause massive blood clots. They can act relatively quickly and immediate medical attention is the best bet for survival!
  2.  Neurotoxins. Neuro refers to the nervous system, so this class of venom is the nervous system toxins. These interfere with your brain. By preventing your brain from sending messages to your body, the animal injecting the venom can either run away or eat their prey without getting hurt.
  3.  Cytotoxins. Cyto means cells, so this class of venom affect cells. The venom will start killing muscle cells, skin cells, or whichever organ system it is in. In sufficient doses, the wide spread cell death renders the victim severely weakened or dead.

Why venom? Venom is actually quite expensive for animals. Not in terms of money, but in terms of energy. It takes a lot of energy, food, and time to be able to produce venom. For most animals, it can take several weeks to recharge their venom stores. Intuitively, it doesn’t make a lot of sense to invest so much into venom.

But it’s a super effective tool. For some snakes, venom paralyzes their prey. They can bite a mouse, and follow it. The mouse will be affected by the venom and won’t be able to put up a fight. This means the mouse won’t resist and potentially hurt the snake. For other animals like lionfish, it means that most animals will leave them alone.

Some animals can even use their venomous status as a bluff. Some vipers and rattlers will give what’s called a dry bite. That’s where they a snake feels threatened enough to strike and bite at the aggressor. But they won’t inject any venom into the wound. The threat usually backs off in fear and shock, giving the snake time to make a quick getaway and retaining its precious stores of venom.

Here is what to do if you get bit by a snake!

Flashy camouflage

With the wide variety of venomous animals, they approach the subject of aesthetics differently. Some animals like the blue ringed octopus or the lion fish go for the flashy approach. They have bright eye catching colours, but these colours warn others not to mess with them. You can probably think of some other animals with bright colours that you know better than to mess with.

Blue ringed octopus pattern-GIPHY

On the other hand, you have animals like the stonefish and certain stingrays. These ones still have some toxic concoctions waiting, but they lie in wait. Stingrays are just extra careful with using their stinger. Since they have to regrow their barb, not just replenish the venom. So they cover themselves in sand to hide from potential predators, keeping their venomous sting for the absolute last resort. Stonefish on the other hand, lie in wait in shallow water and wait for fish to swim too close to their mouths before snapping at them. But they still have several nasty looking spines on the top of their body. If a beach goer didn’t read any warning signs before going for a swim, they just might accidentally step on a hidden stonefish!

Stingray Hiding-Pinterest

Some standout venomous animals

Name: Blue Ringed Octopus

Venom Type: Neurotoxin

Food: small crustaceans

Location: Indo-pacific Ocean, from Japan to Australia

Cool Facts: These little guys are tiny! Maxing out at 20cm. They are still one of the most toxic animals on earth. One of the neurotoxins they have is called tetrodotoxin, and is the same found in the famous fugu, or pufferfish!

Blue Ring Octo-marine.blogcrib.com

Name: Stonefish

Venom Type: Neurotoxin

Food: small fish and crustaceans

Location: shallow water around the indo pacific

Cool Facts: These hidden creatures have sharps spines on the top of their body. If something made the mistake of stepping on those spines, venom would be injected right in and cause lots of problems. It has also recently been discovered that they have a hidden spine, called a lachrymal saber. This is a hidden blade like bone right under their eye that they can use in addition to all the adaptations that they have.


Name: Box Jelly

Venom Type: Cytotoxin

Food: Small Fish

Location: Northern Australia

Cool Facts: Box jellies are usually referred to as the most toxic animals. They definitely do live up to their reputation. They have incredibly potent venom and are hard to see. The bell reaches up 2.5cm in width and the tentacles can be almost a meter long. They also have stinging cells on their tentacles and the bell!

Box Jelly-MakeAGif

Name: Geography Cone Snails

Venom Type: Neurotoxin

Food: Fish

Location: Reefs along the indo-pacific

Cool Facts: These are very venomous snails. They have a harpoon-like tooth that is in their proboscis. They shoot out the venom tipped tooth at a fish and then drag the paralyzed fish back into their mouth.

Cone Snail-Science Friday

Invasive Lions

Some Venomous animals are quite eye catching with their colours. Lionfish for example have beautifully decorated spines. This has made lionfish very attractive to home aquarists, causing an increase in lionfish in home aquariums. However, problems began to occur when people started releasing lionfish in Florida. In their native range of Indo-pacific reefs, lionfish are held in check, but in the Atlantic Ocean, they are untouched by predators. With not predators around, lionfish populations have exploded around pacific reefs.

lionfish on the reef-Lionfishhunter blog

Lionfish are perfect invaders. The venomous spines deter many animals from eating lionfish. Lionfish are heavy eaters. They have big mouths and even bigger appetites. Small fish and crustaceans get sucked up when lionfish use their vacuum mouths. They eat a lot of baby fish, and by eating so many young fish, invasive lionfish have wiped out reefs of big fish like groupers. To add on to all of this, lionfish lay lots of eggs. Up to 2 million every year!

Lionfish eating-GIPHY

The lionfish problem has caught the attention of locals and scientists around the world. People are working together now to tackle the problem. Local divers are catching lionfish and bringing them to chefs, who cook them up. The hope is to use our appetite for fish to deal with the lionfish invasion. There are other methods of control that get more bizarre. Some divers are catching lionfish and then waving them in front of reef sharks. The hope is that sharks will acquire a taste for lionfish and actively hunt them on reefs. Some scientists have turned to robots.  A team of engineers have built an autonomous robot that swims up to lionfish, shock them, and then vacuum up the stunned fish.


-Find out what you can do to prevent the spread of invasives! 

-Take action and remove invasive species around your home!

-Find out why most venomous animals live in warm places (like Australia, India, Mexico etc)

Learning Objectives

-The difference between poisonous and venomous animals 

-Understand warning signs displayed by toxic animals

-Comprehend the destruction potential of invasive species 

Continue to 3. Let's Help the Kelp! »