Classifying animals 8

8-It can be a mollusc an annelid a sponge, an echinoderm or cnidarian.

• Molluscs have got soft bodies which are not segmented.

-Some of them have their feet jointed to the head (cephalopods like octopuses, squids, cuttlefishes, etc.) Cephalopods are generally good with camouflage and some of them also use ink to confuse predators.

-Some others have got a shell divided in two parts called valves (bivalves like clams, mussels, oysters, scallops, etc.).

-Finally, there are molluscs with one or no shell (gastropods like the snails or slugs).

• Annelids are worms with a segmented body. Many of them are parasites.

• Sponges are very simple animals without nervous or circulatory system which filter water to get their food.

• Echinoderms have got their body covered with plaques which are usually spiny (starfishes, sea urchins, etc.).

• And finally, cnidarians are the group of jellyfishes, anemones and corals. Most of them have got stingy cells in their skin, so do not touch them!!!!

Classifying animals 7

7-It is an invertebrate.

Has it got jointed limbs?

Yes, it has. It is an arthropod. Arthropods have got jointed limbs and an exoskeleton.

Now, count the legs and antennae.

-If its got 8 legs and no antennae, it is an arachnid. Some of them have two body parts (cephalothorax and abdomen) for example spiders and scorpions, but others have only one, like harvestmen (opiliones) and mites.

-If its got 6 legs and 2 antennae, it is an insect. Most insects have got 4 wings (excepting flies). They also have a life cycle which includes a metamorphosis (complete or incomplete). Their bodies are divided into 3 parts (head, thorax and abdomen).

-If it has got many legs, 2 antennae and a segmented body it is a myriapod. One pair of legs (2) per segment, centipede. Most centipedes are predators (they eat other animals). Two pairs (4) of legs per segment, millipede

 

-It has got 4 antennae (remember that they are not always visible for the naked eye) and 10 or more feet, they are crustaceans. Most crustaceans live in the water but those who do not need a moist environment (they cannot dry)

 

No, it hasn’t. Go to 8.

Classifying animals 4

4- Fish, amphibians, reptiles and birds lay eggs, but cannot feed milk.

Does it lay its eggs in water?

Yes, it does. Then it is either a fish or an amphibian. Fish and amphibians have to lay their eggs in water because they are not water-thigh (impermeable) and they can dry.

Go to 5.

No, it doesn’t. Then it is either a bird or a reptile. Birds and reptiles descend from dinosaurs and they both can lay their eggs in land because they are water-thigh.

Go to 6.

Classifying animals 6

6-Has it got scales?

Yes, it has. Then it is a reptile. Reptiles have got scales and normally have got four legs. Reptiles without legs are called ophidians (snakes). They are usually carnivores, but there are herbivore reptiles, for example iguanas and some turtles and tortoises.

No, it hasn’t. It is a bird. Birds have got feathers, wings and beaks. Most of them can fly, but some of them cannot. For example, penguins, ostriches or kiwis.

Classifying animals 5

5- Has it got scales?

Yes, it has. Then it should be a fish. Remember that some scales cannot be seen with the naked eye and there are some fishes without scales. However, they all breathe in water using their gills and have got fins to help them swimming.

No it hasn’t. Then it should be a amphibian. Amphibians start their lives in water and they use gills to breathe. Then, after a metamorphosis they can live on land because their gills disappear and they develop lungs. They can also breath through their moist skin.

Classifying animals 3

3-Has it got mammary glands (can it feed milk to its babies)?

Yes, it has. It is a monotreme. Monotremes are mammals that lay eggs. Most of them are extinct but we still can find echidnas and platypus in Oceania (Australia, New Zealand, Tasmania, etc.)

No it hasn’t.

Go to 4.

Classifying animals 2

2-It is a vertebrate. Elephants, snakes, tigers, cats, parrots, pelicans, lungfishes, sharks, dolphins, crocodiles, lizards, frogs, salamanders and Bears are vertebrates.

Does it lay eggs?

Yes, it does. It is oviparous. Go to 3.

No. It doesn’t. It is viviparous (it is born from its mother womb). It is a mammal. Mammals normally have got 4 legs and hair or fur. They also feed their babies with milk from their mother’s breasts because they have mammary glands. Elephants, tigers, cats and bears are mammals. Dolphins are mammals too, but they live in the water and their legs have evolved into flippers.

Classifying animals 1

1-Has it got an internal skeleton? (or a spine/backbone?)

Yes, it has. Go to 2.

No, it hasn’t. Go to 7.