---
title: Coral reef partners and tricksters: clownfish, cleaners, mimics and… — how Mova does on the tests · Biology
description: Lesson 173 of the biology course of Mova's primary school: 5 of 11 tests right, exam 3 of 4, every question with the options, the student's choice, the right answer and why it chose.
---

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# Coral reef partners and tricksters: clownfish, cleaners, mimics and puffers

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**Tests:** 5 of 11 right · **Exam:** 3 of 4 right · **Kind:** plain · **Understood:** 12 of 15 · **Run:** 2026-10-18, commit `f3c23ea72`

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Lesson 173 of the biology course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: [the lesson in the corpora](https://md.mova.elamur.ai/free/en/corpora/school/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/).

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Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: [the lesson's questions in the corpora](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/).

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### Test 1 · wrong ✗ {#t1}

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In Finding Nemo, Nemo swims far out into the open sea. What do real clownfish usually do?

- **1.** They travel with the sea turtles every year, all the way to the beaches — no support
- **2.** They live without any home — **← Mova's choice** · score 10
- **3.** They stay very close to their anemone for safety — **✓ the right answer** · no support
- **4.** They swim across whole oceans — score 10

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**Why:** It took the question to ask what is done. It chose option 2 with score 10, tied with another option at 10 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 173, line 5: «Clownfish live among the tentacles of sea anemones without getting stung; the clownfish chases away fish that eat anemones, and the anemone protects the clownf…», reached through the option's own match among the sentences about the question's things. What matched: it fills the role the question asks for (+4); the same action «live» (+3); the same doer «clownfish» (+3). The right option, 3, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/t1/)

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### Test 2 · right ✓ {#t2}

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«a tiny fish just swam INTO a big fish's mouth and came out?? how» What is going on?

- **1.** The tiny fish was stealing the big fish's teeth — no support
- **2.** It was a fish being eaten that escaped by magic — score 5
- **3.** It is a cleaner fish picking off parasites, and the big fish lets it — **← Mova's choice** · **✓ the right answer** · score 9
- **4.** The big fish was asleep — no support

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**Why:** It took the question to ask what something is like. It chose option 3 with score 9, against 5 for the next best. Its support: lesson 132, line 5: «A sea anemone looks like a flower but is an animal, a relative of jellyfish and corals, that catches small animals with stinging tentacles and pushes them into…», reached through a sentence linked to the one the question matched. What matched: the same doer «relative» (+4); the same thing acted on «small animals» (+4); a different action (counts against) (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/t2/)

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### Test 3 · wrong ✗ {#t3}

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«octopus n a shrimp in the burrow, how many legs n arms total»

- **1.** 10 — **← Mova's choice** · no support
- **2.** 12 — no support
- **3.** 18 — **✓ the right answer** · no support
- **4.** 16 — no support

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**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/t3/)

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### Test 4 · wrong ✗ {#t4}

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«2 octopuses, 3 pufferfish. how many arms»

- **1.** 10 — **← Mova's choice** · no support
- **2.** 21 — no support
- **3.** 16 — **✓ the right answer** · no support
- **4.** 8 — no support

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**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/t4/)

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### Test 5 · wrong ✗ {#t5}

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What would happen if the goby left the shrimp's burrow?

- **1.** Nothing, because the shrimp has perfect eyes and sees danger first itself — no support
- **2.** The nearly blind shrimp would have no guard to warn it of danger — **✓ the right answer** · no support
- **3.** The shrimp would dig faster — **← Mova's choice** · score 4
- **4.** The shrimp would see better — no support

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**Why:** It took the question to ask what happens next. It chose option 3 with score 4, the only option with support. Its support: lesson 173, line 7: «A nearly blind shrimp, with ten legs like other shrimps, digs and cleans a burrow, and a goby fish keeps watch at the entrance; neither could live as safely al…», reached through a sentence linked to the one the question matched. What matched: the same action «dig» (+2); the same doer «blind shrimp» (+2). The right option, 2, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/t5/)

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### Test 6 · right ✓ {#t6}

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«lol that sea slug is so bright, it's begging to be eaten» What is right?

- **1.** No, bright colours warn that it tastes bad or stings — **← Mova's choice** · **✓ the right answer** · score 7
- **2.** Yes, bright colours make it extra tasty, like sweets — no support
- **3.** Yes, it wants to be eaten — no support
- **4.** No, it is bright because it is made of plastic — no support

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**Why:** It took the question to ask which statement is true. It chose option 1 with score 7, the only option with support. Its support: lesson 173, line 14: «Sea slugs called nudibranchs are bright to warn that they taste bad or sting, and some keep algae inside them and make food from sunlight.», reached through the same lesson line as the sentence the question matched. What matched: the same action «taste» (+4); the same property (+3). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/t6/)

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### Test 7 · wrong ✗ {#t7}

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A shark bites at a small fish's tail, where a big round spot is, and the fish shoots away the other way. What happened?

- **1.** The shark was not hungry — no support
- **2.** The fake eye spot fooled the shark about which end was the head — **✓ the right answer** · score 3
- **3.** The spot is a real eye that saw the shark coming from behind — score 3
- **4.** The fish was too hard to bite — **← Mova's choice** · score 7

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**Why:** It took the question to ask which statement is true. It chose option 4 with score 7, against 3 for the next best. Its support: lesson 134, line 16: «Many reef fish in the film are hard to keep in tanks, needing lots of space, stable clean salt water and the right food; Gill's kind, the Moorish idol, is one…», reached through the option's own match among the sentences about the question's things. What matched: the same property (+3); the same light verb (be, have, do, get, go) (+2); its «because» matches the remembered cause (+2). The right option, 2, scored 3. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/t7/)

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### Test 8 · right ✓ {#t8}

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In a cartoon a pufferfish blows up with air like a balloon and floats away. What is real?

- **1.** It explodes after puffing — score 2
- **2.** It always fills up with air and floats away into the sky — score 5
- **3.** It cannot puff up at all — score 0
- **4.** It swallows water to swell up, and it stays in the water — **← Mova's choice** · **✓ the right answer** · score 11

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**Why:** It took the question to ask which statement is true. It chose option 4 with score 11, against 5 for the next best. Its support: lesson 90, line 13: «Pufferfish swallow water fast to blow up into a prickly ball, and many also have strong poison.», reached through a sentence linked to the one the question matched. What matched: the same action «swallow» (+3); the same doer «pufferfish» (+3); the same thing acted on «water» (+3); its «because» matches the remembered cause (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/t8/)

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### Test 9 · right ✓ {#t9}

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«that eel n grouper are mates?? they're fish ffs» Is it true they hunt together?

- **1.** Yes, but only in aquariums — no support
- **2.** No, groupers eat eels — no support
- **3.** No, eels and groupers always fight — no support
- **4.** Yes, the grouper shakes its head to invite the eel and they hunt as a team — **← Mova's choice** · **✓ the right answer** · score 9

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**Why:** It took the question to ask which statement is true. It chose option 4 with score 9, the only option with support. Its support: lesson 173, line 11: «Groupers shake their heads at moray eels to invite them to hunt together; the eel goes into cracks and the grouper catches fish that flee into open water.», reached through the same lesson line as the sentence the question matched. What matched: the same action «shake» (+4); the same doer «groupers» (+2); its «because» matches the remembered cause (+2); the same thing acted on «heads» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/t9/)

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### Test 10 · wrong ✗ {#t10}

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«saw an octopus turn into a lionfish then a snake on youtube, fake right» What is right?

- **1.** It is fake, octopuses cannot change shape — **← Mova's choice** · score 5
- **2.** It is real: the mimic octopus copies dangerous animals — **✓ the right answer** · score 5
- **3.** Octopuses only copy rocks — score 5
- **4.** It was a real lionfish that turned into a snake — score 5

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**Why:** It took the question to ask which statement is true. It chose option 1 with score 5, tied with another option at 5 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 173, line 8: «The mimic octopus copies the shapes and movements of dangerous animals such as lionfish and sea snakes; it was first noticed in 1998 off Indonesia.», reached through a sentence linked to the one the question matched. What matched: the same doer «mimic octopus» (+3); the same thing acted on «shapes» (+3). Against it: a different action (counts against) (-1). The right option, 2, scored 5. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/t10/)

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### Test 11 · right ✓ {#t11}

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Divers spear lionfish and restaurants cook them. Why is this helpful in places where lionfish spread?

- **1.** Lionfish are endangered — no support
- **2.** Lionfish eat many small reef fish and have few hunters there — **← Mova's choice** · **✓ the right answer** · score 5
- **3.** It makes the water warmer — no support
- **4.** Lionfish are the reef's only cleaners, so the fish get sick without them — no support

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**Why:** It took the question to ask why something happens (its cause). It chose option 2 with score 5, the only option with support. Its support: lesson 173, line 15: «Lionfish have venomous spines and hunt small fish; where they have spread far from their home seas and few hunters eat them, divers hunt them and chefs cook th…», reached through the same lesson line as the sentence the question matched. What matched: the same action «eat» (+4); a different doer (counts against) (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/t11/)

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### Exam question 1 · formal language · wrong ✗ {#e1}

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Which of the following statements most accurately characterises the relationship between the clownfish and the sea anemone?

- **1.** The clownfish consumes the anemone gradually — score 3
- **2.** The anemone stings the clownfish to death — **← Mova's choice** · score 6
- **3.** The two organisms are entirely indifferent to each other and never interact in any manner — no support
- **4.** Each confers protection upon the other, the fish repelling predators of the anemone — **✓ the right answer** · no support

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**Why:** It took the question to ask who or what does it. It chose option 2 with score 6, against 3 for the next best. Its support: lesson 132, line 3: «It is a good deal for both: the anemone keeps the clownfish safe from bigger fish, and the clownfish cleans the anemone and chases off fish that would nibble i…», reached through a sentence linked to the one the question matched. What matched: it fills the role the question asks for (+4); the same doer «anemone» (+3); the same thing acted on «clownfish» (+3). Against it: a different action (counts against) (-4). The right option, 4, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/e1/)

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### Exam question 2 · formal language · right ✓ {#e2}

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Identify the principal function of the false eye spot situated near the tail of certain reef fish.

- **1.** To mislead a predator as to the position of the head — **← Mova's choice** · **✓ the right answer** · no support
- **2.** To enable the fish to perceive objects behind it — no support
- **3.** To absorb sunlight for the purpose of warmth — no support
- **4.** To attract the attention of divers — no support

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**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/e2/)

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### Exam question 3 · formal language · right ✓ {#e3}

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Select the response consistent with the established facts concerning the mimic octopus.

- **1.** It imitates the form and movement of dangerous animals such as lionfish and sea snakes — **← Mova's choice** · **✓ the right answer** · score 5
- **2.** It reproduces the vocal calls of whales — no support
- **3.** It transforms itself into a genuine fish — score 3
- **4.** It was described by naturalists in antiquity — score 5

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**Why:** It took the question to ask which statement is true. It chose option 1 with score 5, tied with another option at 5 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 173, line 8: «The mimic octopus copies the shapes and movements of dangerous animals such as lionfish and sea snakes; it was first noticed in 1998 off Indonesia.», reached through a sentence linked to the one the question matched. What matched: the same action «copy» (+3); the same doer «mimic octopus» (+3). Against it: a different thing acted on (counts against) (-1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/e3/)

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### Exam question 4 · formal language · right ✓ {#e4}

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Ascertain the means by which the pufferfish renders itself too large to be consumed.

- **1.** Its skeleton is extended by additional bones — no support
- **2.** It adheres to larger fish for concealment — no support
- **3.** Water is swallowed so that the body is distended into a sphere — **← Mova's choice** · **✓ the right answer** · score 5
- **4.** Air is expelled forcibly through its gills — no support

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**Why:** It took the question to ask which statement is true. It chose option 3 with score 5, the only option with support. Its support: lesson 173, line 10: «Pufferfish swallow water to swell into a ball too big to eat, and a male pufferfish draws beautiful circles in the sand on the sea floor to attract a female.», reached through the remembered sentence the question matched. What matched: the same thing acted on «water» (+4); the same action «swallow» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/173-coral-reef-partners-and-tricksters-clownfish-cleaners-mimics-and-puffers/e4/)

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- ← previous: [172. Coral reef builders: polyps, bleaching, sand fro…](https://md.mova.elamur.ai/free/en/school-run/biology/172-coral-reef-builders-polyps-bleaching-sand-from-parrotfish-and-giant-clams/)
- next →: [174. Reef giants and wanderers: whale sharks, mantas,…](https://md.mova.elamur.ai/free/en/school-run/biology/174-reef-giants-and-wanderers-whale-sharks-mantas-dugongs-and-sea-turtles/)
- ↑ back to [Biology](https://md.mova.elamur.ai/free/en/school-run/biology/)