According to the same passage about snorkelling among colourful fish, identify which of the following creatures or fish the writer did not see.

Introduction / Context:
This reading comprehension question checks careful attention to detail in the description of marine life. The passage lists several sea creatures and groups of fish that the writer observed while snorkelling. The question asks which of the given options was not seen by the writer. This type of question develops precise reading habits and prevents careless assumptions based on partial memory.

Given Data / Assumptions:
The passage specifically mentions:

• Sea cucumbers, sea anemone, clown fish, star fish, sea horses, parrot fish, butterfly fish, and colourful salt water fish.
• A shoal of canary yellow fish doing a merry dance.
• Another shoal with vibrant blue fish following the first group.
• No mention of any green fish group, especially not vibrant green fish.

Concept / Approach:
The approach is to match each option with the items explicitly listed in the passage. If a creature or fish is clearly named, then it was seen. If it is not mentioned, then that option may be the correct answer. Careful reading shows that canary yellow fish, sea horses, and parrot fish all occur in the description, while vibrant blue fish is mentioned but vibrant green fish is not. The closest sounding phrase is vibrant blue fish, which may confuse some readers, but the colour is different. Therefore, vibrant green fish is the one not seen by the writer.

Step-by-Step Solution:
Step 1: Recall the list of marine creatures in the passage, including sea horses and parrot fish. Step 2: Note the description of a shoal of canary yellow fish, which matches option a. Step 3: Remember that another shoal of vibrant blue fish followed the yellow ones. Step 4: Compare each option with the passage: canary yellow fish, sea horses, and parrot fish are all explicitly mentioned. Step 5: Notice that the passage never refers to vibrant green fish, so option d does not appear anywhere. Step 6: Conclude that vibrant green fish is the creature not seen by the writer.

Verification / Alternative check:
To verify, mentally reconstruct the colourful scene: first, the canary yellow fish dance, then the vibrant blue fish follow. The description of colours in the water focuses on yellow and blue, and the passage already uses many names of creatures. If green fish had been mentioned, it would likely stand out in that list, but it does not. Therefore, checking the colour adjectives carefully confirms that vibrant green fish is absent from the writer observation.

Why Other Options Are Wrong:
Option a is wrong because canary yellow fish are clearly mentioned as doing a merry dance. Option b is incorrect since sea horses appear in the list of animals observed. Option c is wrong because parrot fish are specifically named. These options refer to creatures that are clearly part of the underwater scene as described in the passage, so they cannot be the answer to a question asking which was not seen.

Common Pitfalls:
One common mistake is to misremember the colour adjectives and assume that any bright colour mentioned in the options must have appeared in the text. Another pitfall is reading too quickly and not distinguishing between blue and green in the descriptions. To avoid such errors, slow down and underline or mentally mark key descriptive words, especially when colours or numbers are involved in detail questions.

Final Answer:
The writer did not see vibrant green fish, so option d is correct.