--- title: Octopuses, squid and cuttlefish — a lesson of Mova's school · trees and pragmatics description: «Octopuses, squid and cuttlefish», a lesson of the biology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Octopuses, squid and cuttlefish are molluscs, cousins of snails, whose shells have shrunk inside or vanished, which turned them into soft, --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/) / Octopuses, squid and cuttlefish # Octopuses, squid and cuttlefish Lesson 39 of the biology course of Mova's primary school: 19 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/biology/39-octopuses-squid-and-cuttlefish/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/0/) — Octopuses, squid and cuttlefish are molluscs, cousins of snails, whose shells have shrunk inside or vanished, which turned them into soft, clever, shape-changing hunters. - [1](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/1/) — An octopus has eight arms, three hearts and blue blood, and no bones at all except a parrot-like beak, so it can squeeze through a hole the size of a coin. - [2](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/2/) — About two thirds of its nerve cells are in its arms, so each arm can feel, taste and make simple decisions on its own while it explores a different rock. - [3](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/3/) — It can open a jar to reach a crab, turn sandy grey to vanish against a rock, and squirt a cloud of ink, the same black that colours squid ink pasta. - [5](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/5/) — An octopus has eight arms, three hearts and blue blood: two hearts pump blood through the gills and the third round the body. - [6](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/6/) — The octopus's body heart stops while it swims, so swimming tires it quickly, and octopuses mostly crawl over the rocks instead. - [7](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/7/) — An octopus has no bones; its only hard part is a parrot-like beak, so it can squeeze through any gap bigger than the beak. - [8](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/8/) — An octopus has about 500 million nerve cells, about two thirds of them in its arms, and its suckers can taste what they touch. - [9](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/9/) — Octopuses can solve puzzles, open jars, learn by watching and remember people; wild ones carry coconut shell halves to hide in. - [10](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/10/) — In 2016 an octopus called Inky escaped from an aquarium in New Zealand: he slipped through a small gap at the top of his tank, crossed the floor and slid down a drainpipe into the sea. - [11](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/11/) — Most octopuses seem to be colour-blind, yet they match the colours around them very well, and scientists are still working out how. - [12](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/12/) — Octopus skin has thousands of tiny colour bags it can open and close in a fraction of a second, and it can raise bumps to copy the texture of rock. - [13](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/13/) — Octopuses, squid and cuttlefish squirt ink made of melanin to hide or to make a fake blob while they jet away; cooks use squid ink to colour pasta black. - [14](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/14/) — Colossal squid have the largest eyes known of any animal, about 27 cm across, and the giant squid was first filmed alive in its deep home only in 2012. - [15](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/15/) — Sperm whales dive deep to hunt giant squid, and many sperm whales carry round scars left by the squid's suckers. - [16](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/16/) — A squid moves fast by jet propulsion: it squirts water out through a funnel called a siphon and shoots the other way. - [17](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/17/) — The cuttlebone is a cuttlefish's inside shell, full of tiny chambers of gas and liquid that help it float or sink; budgies peck it for calcium. - [18](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/18/) — The blue-ringed octopus is only golf-ball size, but its venom can kill an adult; its blue rings flash as a warning, so never pick up an octopus from a rock pool. - [19](https://md.mova.elamur.ai/free/en/corpora/school/biology/39-octopuses-squid-and-cuttlefish/19/) — A mother octopus guards and cleans her eggs without eating until they hatch, and soon after she dies; one deep-sea mother guarded hers for four and a half years. - ← previous: [Spiders, scorpions and other eight-legged creatures](https://md.mova.elamur.ai/free/en/corpora/school/biology/38-spiders-scorpions-and-eight-legged-creatures/) - next →: [Counting animals: legs, arms, wings and tails](https://md.mova.elamur.ai/free/en/corpora/school/biology/40-counting-legs-arms-wings-and-tails/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/)