Invertebrates ate the largest and most diverse group of animals on the Earth. More than 95% of the known animal species are invertebrates. They have very varied characteristics.
Habitats: invertebrates liven in aquatic and terrestrial environments
A wide range of sizes: they range from microscopic water fleas to the giant squid
Movement: some invertebrates are motile (movnig); others are sessile (sttionary)
Skeleton: most invertebrates have exoskeletons, an external skeleton
VIDEO ACTIVITY:
Now, we can want a video about them:
Watch the video: (visualiza el vídeo)
Fill in the gaps and translate the words in bold (completa los huecos y traduce las palabras en negrita)
Answer the questions (responde a las preguntas que vienen al final)
INVERTEBRATE ANIMALS
Today we are going to learn about the invertebrate ___________(1). You all know that the animals are divided into two big groups, the ____________(2) that have an internal ____________(3) formed by bones and the invertebrates that have no __________(4). All the invertebrates are _____________(5), and we classify them in 6 big groups: Sponges, jellyfish, corals, worms, mollusks, echinoderms and arthropods. The sponges are _____________(6) animals, that are sac shaped and their body is full of pores. It is very easy to remember this group because many times we use them in the shower for our personal hygiene. Yes, many of the sponges we use in the shower are invertebrate animals. The jellyfish are invertebrate animals that live in the _____________(6). Their bodies are gelatinous and have tentacles. The truth is that when they appear in the beach it is very annoying because their tentacles have small venomous stingers that produce very unpleasant bites. Corals are tiny marine animals that produce limestone residue, which give rise to _____________(7) shapes. Do you know this animal? Exactly, it’s a _____________(8). Worms are soft and long invertebrate animals that move by _____________(9) their body in the ground, because they have no feet. They can be aquatic or terrestrial. There are some worms that can be harmful and that is why we must be careful with them. Can you see this _____________(10)? Well snails form part of the _____________(11) group. Mollusks have a soft body, without legs and can also be aquatic or _____________(12). Some, like this snail, this clam and mussels, protect their soft body with shells, but there are other mollusks that don’t have a _____________(13) to protect themselves like slugs or octopuses. The echinoderms are _____________(14) aquatic animals. Their bodies have calcareous plates that form a shell. Some echinoderms are balloon shaped and are covered in spikes that they use to defend themselves, like sea urchins. Others are star shaped, and are of course called _____________(15). The arthropods are the most abundant animals on the _____________(16). Of every 100 animals that exist, 80 are arthropods. These invertebrate animals have their body covered by an _____________(17) skeleton called a cuticle. The most common way to classify the arthropods is by the number of legs they have. This way we can classify them in four big groups. _____________(18) with 6 legs. In this group insects like ants and flies are present. Arthropods with 8 legs, where for example the arachnids like _____________(19) and scorpions are. Arthropods with 10 legs include the crustaceans, like crabs and lobster. Arthropods with more than 10 legs like this centipede that as you can see has much more than 100 legs are called myriapods. Well now you know a bit more about the invertebrates.
QUESTIONS:
1. What group do starfish belong to?
2. What group do snails belong to?
3. How can we classify the arthropods?
4. What are myriapods?
5. Search an image of each group and write the name of the animal.
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