Can squid eat sharks


Information about the animal class invertebrates

Features and peculiarities of invertebrates:

"Invertebrates" are animals without a spine. By and large, they include:

all mollusks (e.g. snails, mussels and squid),
Echinoderms (e.g. starfish),
Sponges and

They also include insects and arachnids, which we have granted an extra category on Most animals are invertebrates - only about 4% of all living things are vertebrates, so mammals, birds, amphibians and reptiles and fish. We inform you on this page about mollusks, echinoderms and crustaceans. Sponges and worms follow.

Squid - Photo: JonMilnes / Shutterstock

1. Mollusks

  • Mollusks are invertebrates.
  • Many mollusks have a clam.
  • All molluscs have a rasp tongue.

If you go looking for the number of molluscs, you will find very different information. The fact is: New species are added almost every day and there are countless species that have not yet been discovered. The figures given are therefore only rough estimates.

How do you distinguish molluscs from other animal species?

What invertebrates, in contrast to other animal species, almost all have in common is the rasp tongue. The animals use it to grate, chop and ingest food. Mollusks do not have a skeleton. Your body is mainly made up of soft flesh held together by muscles and skin (called the "coat"). Not all of them have a hard lime shell on the outside, e.g. B. Squids. Even snails don't always crawl around with a house, e.g. B. Nudibranchs.

Where do mollusks live?

Mollusks mostly live in water, a few also on land (snails).

How do mollusks move?

They crawl, swim, or run.

What do mollusks eat?

Mollusks feed on plankton, algae or lichens. Depending on the species, they also eat other molluscs, crabs or fish.

How do mollusks reproduce?

Mollusks mostly lay eggs from which larvae hatch.

Fun fact: the shell on the ear

When we hold a spiral-shaped shell to our ear, we think we can hear the sound of the sea. How so? The shape of the mussel or snail shell amplifies every sound in the vicinity, no matter how quiet it is. Incidentally, small enclosures sound different than large ones.


Who would have thought that sea urchins were important to nature? Fact. Because they eat algae, they prevent them from spreading too much and help to maintain a healthy, intact underwater landscape. More about biodiversity.

There are over 130,000 species of molluscs:
Snails:approx. 100,000
Shellfish:about 10,000
Cephalopods / octopuses:approx. 1,000
Beetle snails:approx. 900

2. Echinoderms

  • Echinoderms have a skin made up of spines.
  • Echinoderms live exclusively in water.
  • Echinoderms lay eggs.

Echinoderms developed over 500 million years ago.

Where do echinoderms live?

They mostly live on the sea floor, especially in shallower coastal areas.

What do echinoderms eat?

Depending on the type, plants and / or meat. Sea urchins are z. B. omnivores or herbivores. Sea rollers swallow sand in the hope that there is something to eat in it. Starfish prey on mussels. Sea lilies and hair stars filter the water for food.

Starfish - Photo: aquapix / Shutterstock

How do echinoderms move?

Echinoderms swim, dig, hike with special feet or stay in one place for their entire life.

How do echinoderms reproduce?

Echinoderms lay eggs.

There are about 6,300 species of echinoderms:
Brittle stars:approx. 2,000
Starfish:approx. 1,500
Sea rollers:approx. 1,200
Sea urchin:approx. 950
Sea lilies:approx. 620
Hair stars:about 550

3. Crustaceans

  • Crustaceans are invertebrates.
  • Most crabs have a chitin shell.
  • Crustaceans breathe through their gills.
  • Crabs are made from eggs.

Live crabs for more than 500 million years on earth and are related to insects. They breathe with gills, even those crabs that live on land.

Where do crustaceans live?

Crabs live in all waters of the earth, a few also on land.

What do crustaceans eat?

Crustaceans feed on plant plankton.

Hermit Crab - Photo: marima / Shutterstock

How do crustaceans move?

Crabs run or swim.

How do crustaceans reproduce?

Crustaceans develop from eggs and are initially larvae, from which they then transform into adults.

There are approximately 67,000 species of crustaceans:
Higher cancers:approx. 28,000
Shellfish:approx. 15,000
Copepodsapprox. 12,000
Tongue worms:130
Fish lice:130
Horseshoe prawns:11