5. The Great Invertebrate Debate


Grow a spine? I think not! It’s fun to wiggle and jiggle along! Join the junior biologist team as we learn all about the fascinating creatures that flourish without a backbone, including some hands on time with our wet lab animals.

Invertebrates are a huge group of animals that account for 97% of all known animals! The one thing they all have in common is that they do not have a backbone. However, they are hugely varied and occupy niches all around the world!

rise and shine!

What did we do today?

-Learned how varied invertebrates are and how important they are to food webs

-Appreciated the variation in invertebrate adaptations that let them flourish

-Got some hands on time in the wetlab, touching some fan favourite invertebrates

Things to ask your junior biologist

-What animal did they get to touch inside the wetlab?

    -The animals we touch can change depending on how they are, but we usually get to touch sea anemones, sea urchins, and sea stars!

-What is your favourite invertebrate?

            -The invert world is huge, so your junior biologist might need some time to think. Some might like bobbit worms for being sneaky ambush predators, others might like sea bunnies because they are so cute!

-What is an extremophile?

            -Extremophiles are animals that can live and often thrive in extreme environments. Places like underwater volcanic vents are great examples of extreme environments. 

The great debate!

For some people, invertebrates are more than often overlooked. They think of worms wiggling around or the spiders. However, invertebrates are everywhere! Out of all the animals that are currently known to science, invertebrates make up 97% of them! They occupy almost every niche and have some of the coolest adaptations to help them survive. The question we want to ask is, which invertebrate has the best adaptations? 

The covert invert

Some invertebrates choose to live the sneaky life. Preferring to hide and wait for prey to get too close to them. The famous one in particular is the bobbit worm. These animals wait in the sand with their antennae exposed, waiting for fish to get too close. Once a fish gets too close and triggers their antennae, the worm lunges and grabs onto the prey. Some scientists say that bobbit worms can strike with enough force to cut the fish in half!

Bobbit worm finds dinner
Link from GIPHY

The invert that brings the hurt

One of the more famous invertebrates in the past few years are mantis shrimps. These animals actually are an entire order, or group of animals. Roughly they can be broken down into two groups. One group is the spearers. They have long appendages with barbs that they use to lunge forward to grab onto prey.

the two types of mantis shrimp!
Link from GIPHY

The other, more famous group are the smashers. The most famous one is the peacock mantis shrimp. They have little clubs instead of pincers, and these clubs are an amazing adaptation. Mantis shrimp like eating crabs and clams, and they use their smashers to destroy the shells. The smashers are able to accelerate like a .22 caliber bullet. They do it so fast, that the water between the smasher and the poor prey animal rushes out of the way, forming a cavitation bubble. When this bubble collapses in the tiny fraction of a second, it generates light as well as temperatures equal to that of the sun’s surface. So even if the mantis shrimp misses the first blow, the cavitation bubble can still stun or kill the prey!

Mantis smash!
Link from GIPHY

The invert in the dirt

Moon snails are found in our waters off the BC coast. They are beautiful looking snails with a wide skirt around a seemingly tiny shell. Yet, they are a fearsome predator. We might not see them as terrifying animals, but to a clam, moon snails are the boogeymen.

The boogeyman of the clam world
Picture from seashore to forest floor

To eat the clams and mussels that they want, moon snails will envelop the clam and drill into their shells. Their radula, which is like a tongue with teeth, will wear away at the shell, and some snails can even use acid to make the job easier. Once they have an entrance to the clam, they will drink up the clam tissues from the inside.

a moon snail's handiwork
Picture from Rebecca Heisman

The invert that will convert stingers

The Portuguese man of war is a jellyfish looking animal found in the open ocean. They have long tentacles that contain stingers with a potent venom in them. In fish, it’s enough to paralyze and kill them, and in humans it will cause severe pain. Yet the beautiful blue sea slug will actively find Portuguese man of wars and eat their tentacles. They not only avoid getting stung, but will adopt them as their own defence. These slugs live out in the open ocean, so not much is known about them, but they are amazing to look at! 

Blue sea slugs

Extreme living

The ocean has lots of different habitats for animals, and each habitat has their own challenges. Some habitats however, seem to be inhospitable. These are places that have extreme challenges. One easy example is the bottom of the ocean, by volcanic hydrothermal vents. These communities feature superheated waters spewing out, reaching temperatures upwards of 400C. The water coming out also carries tons of acidic and toxic chemicals from beneath the earth’s crust. Finally adding in the crushing pressure of the ocean depth and total lack of sunlight, these vents seem like the exact opposite place where we’d find animals

Not the most hospitable place on eart h
GIF from gfycat

Yet, the hydrothermal vents communities can be teeming with life. There are bacteria that can get their energy needs from the chemical soup that comes out of the vents. These bacteria are the basis of the food web down there. Worms, crabs, and shrimp are able to trap or filter out the bacteria from the water. The animals living down here have to survive under extreme circumstances, and are justifiably called extremophiles.

Giant tube worms thrive in the depths
Picture from National Geographic

Kiwa crabs are one example of an extremophile. Discovered in 2005, these crabs are also called yeti crabs. That's because of the numerous hairs covering the crab's body. These hairs, or setae, play host to a ton of a special bacteria. These bacteria are believed to be a food source for the crab, but more research is always needed! Perhaps your junior biologist will be the future biologist behind a huge deep sea discovery!!

Deep seas, deep problems

The deep sea is hard to explore for humans. We have to use special and expensive submarines to deal with all the challenges present in this part of our world. The few expeditions that we’ve made down here show us amazing things. From scary looking gulper eels to the widely adored Dumbo octopus, the deep sea is a treasure chest for explorers.

Yet, even though it’s so far removed from humans, we are still having an impact on this fragile ecosystem. Last year, a team of scientists were able to get a view of the deepest part of our ocean, and they were greeted by a plastic bag. We need to do a better job of being conscious of how our choices everyday are and will affect the planet.

This should not be in the deepest part of the ocean
Picture from Smithsonian Magazine

We’ve all heard about the 3 R’s, but did you know that reduce, reuse, recycle is the order of how you’re supposed use it? Best thing to do is to reduce our use of plastic. Vancouver rang in the New Year with a ban on Styrofoam containers and this is a great first step. Making smart choices like bringing your own containers and mugs to restaurants and cafes will reduce the use of other containers. At the grocery store, you can skip the clear plastic produce bags and choose products that come in less packaging. Whatever plastic you do end up using can be reused for other things, and recycling should be the last resort. 

Do your part!
Picture from Shoptwiz

The plastic problem that is happening is not one person’s fault. It’s the culmination of all of us buying and using disposable plastic. Therefore, we can be the ones to step up and fix this situation. It might seem trivial to use one less plastic bag, but when we all do something small together, great things can happen!


-Look around your home and see what you can reduce! 

-Enjoy the beauty of BC's natural world and leave it better than when you arrived 

-Learn more about crazy invertebrates! 

Learning Objectives

Learning outcomes

-Understand that invertebrates are a large group of animals with many different adaptations

-Learn how some ocean invertebrates survive in different habitats 

-See how our actions leave consequences that affect every part of the planet 

Continue to 6. Down Low on the Micro »