--- title: Coral reefs, rockpools and the seashore — a lesson of Mova's school · trees and pragmatics description: «Coral reefs, rockpools and the seashore», a lesson of the biology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: A coral reef looks like coloured rock, but it is built by billions of tiny animals called polyps, cousins of jellyfish, that make --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/) [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/) / Coral reefs, rockpools and the seashore # Coral reefs, rockpools and the seashore Lesson 9 of the biology course of Mova's primary school: 17 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/9-coral-reefs-rockpools-and-the-seashore/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/0/) — A coral reef looks like coloured rock, but it is built by billions of tiny animals called polyps, cousins of jellyfish, that make limestone skeletons and keep tiny algae inside their bodies to share food made from sunlight. - [1](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/1/) — Reefs are the busiest neighbourhoods in the sea: a clownfish lives in a stinging anemone, a little cleaner wrasse runs a cleaning station for big fish, and parrotfish crunch coral and turn it into white sand. - [2](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/2/) — The seashore is a harder home, because twice a day the tide goes out and leaves rockpool animals in sun, wind and beaks: limpets clamp down, anemones fold into blobs of jelly and crabs hide under weed. - [3](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/3/) — In Finding Nemo Marlin raises Nemo alone after Nemo's mum dies; real clownfish all hatch as males, and when the female of a group dies, the biggest male turns into the new female, so real Marlin would have become Nemo's mum. - [4](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/4/) — In SpongeBob SquarePants Patrick Star is famously brainless, and that is the one true joke: a real starfish has no brain at all, yet it walks on hundreds of tube feet and eats mussels with its stomach pushed out of its body. - [6](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/6/) — All clownfish hatch as males, and the biggest one in a group can turn into the female. - [7](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/7/) — Corals are tiny animals called polyps, related to jellyfish, that build limestone skeletons and keep algae inside that make food from sunlight, so reef corals need clear, sunny, shallow water. - [8](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/8/) — The Great Barrier Reef off Australia is about 2,300 km long and is the largest structure built by living things. - [10](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/10/) — Parrotfish scrape algae off coral with beak-like teeth, grind up coral rock and pass it out as fine sand, and one large parrotfish can make hundreds of kilograms of sand a year. - [11](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/11/) — Cleaner wrasse pick parasites and dead skin off big fish, even inside their mouths, and the big fish does not eat its cleaner, so both win. - [12](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/12/) — Starfish move on hundreds of tiny tube feet worked by water pressure, push their stomach into a mussel's shell to digest it, can regrow lost arms, and have no brain. - [13](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/13/) — At low tide beadlet anemones pull in their tentacles and become jelly blobs to keep moist; they sting prey with tiny harpoon cells, but too weakly to hurt a person's fingers. - [14](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/14/) — Crabs walk sideways because their leg joints bend best that way, though many can also walk slowly forwards, have 10 legs counting the 2 claws, and grow by moulting their hard shell. - [15](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/15/) — Limpets graze algae under water and clamp tight when the tide goes out, return to their own home scar on the rock, and their teeth are one of the strongest natural materials known. - [16](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/16/) — The Portuguese man o' war is not a jellyfish but a colony of tiny animals floating under a gas-filled sail, with stinging tentacles that can trail over 10 metres; even a dead one on the beach can sting. - [17](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/17/) — Seaweeds are algae with no roots, only a holdfast gripping the rock, and bladder wrack's air bubbles lift it towards the light when the tide is in. - [18](https://md.mova.elamur.ai/free/en/corpora/school/biology/9-coral-reefs-rockpools-and-the-seashore/18/) — In seahorses the female puts her eggs into the male's belly pouch and the father gives birth, sometimes to over a thousand babies at a time. - ← previous: [The ocean: open sea, sunlit zone and the deep dark](https://md.mova.elamur.ai/free/en/corpora/school/biology/8-the-ocean/) - next →: [Rivers, lakes and ponds](https://md.mova.elamur.ai/free/en/corpora/school/biology/10-rivers-lakes-and-ponds/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/)