Biologists have discovered that the mimic octopus (Thaumoctopus mimicus) possesses a remarkable defensive adaptation. When threatened by predators, th...

Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!

Sentence Structure

Sentence 1:

• Biologists
  • have discovered
    • that the mimic octopus (Thaumoctopus mimicus)
      • possesses a remarkable defensive adaptation.

Sentence 2:

• When threatened by predators,
• this cephalopod
  • can alter its body shape and coloration,
    • effectively camouflaging (?)
      • to resemble more dangerous marine animals
        • such as lionfish or sea snakes.

Understanding the Meaning

Let's start with the first sentence:

• "Biologists have discovered that the mimic octopus (Thaumoctopus mimicus) possesses a remarkable defensive adaptation."
  • We're learning about a specific type of octopus
  • It has some kind of special defense mechanism

Now the second sentence gives us the details:

• "When threatened by predators"
  • This sets up the condition - when the octopus is in danger
• "this cephalopod"
  • This refers back to the mimic octopus we just learned about
  • "Cephalopod" is just the scientific term for this class of sea creatures
  • Notice: "this cephalopod" is singular - we're talking about one creature
• "can alter its body shape and coloration"
  • The octopus can change how it looks

Now here's where we need to fill in the blank:

• "effectively camouflaging _____"

Let's look at our choices:

• We're deciding between: itself, themselves, them, or it
• These are all pronouns, so we need to figure out what noun they're referring back to

What do we notice about the structure here?

• The subject doing the action is "this cephalopod" (singular)
• The action is "camouflaging" - disguising something
• But what is being camouflaged?
• The octopus is camouflaging THE OCTOPUS
  • The subject and the object are the same thing
  • The cephalopod is performing an action on itself
• When the subject and object are the same entity, we need a reflexive pronoun (the -self or -selves forms)
• Since "this cephalopod" is singular, we need the singular reflexive form

So we need itself - this matches our singular antecedent and shows the octopus is camouflaging its own body.

The rest of the sentence confirms this:

• "to resemble more dangerous marine animals such as lionfish or sea snakes"
  • This explains the purpose - the octopus disguises itself to look like scarier creatures

Grammar Concept Applied

Using Reflexive Pronouns When Subject and Object Are the Same

When the subject of a sentence performs an action on itself (rather than on something else), we use reflexive pronouns (called reflexive because they "reflect" back to the subject):

Singular reflexive pronouns: myself, yourself, himself, herself, itself
Plural reflexive pronouns: ourselves, yourselves, themselves

The key pattern:

• Subject acts on something else: The octopus camouflages it (some other object)
  • Here "it" refers to a different entity
• Subject acts on itself: The octopus camouflages itself
  • Here the octopus is both the one doing the action AND the one receiving it
  • We must use the reflexive form

In our question:

• Subject: "this cephalopod" (singular)
• Action: camouflaging
• Object: the same cephalopod (it's disguising its own body)
• Therefore: "camouflaging itself" ✓

Other examples:

• The cat cleaned itself after the meal. (not "cleaned it")
• The students prepared themselves for the exam. (not "prepared them")
• The mirror reflects itself in the opposite mirror. (not "reflects it")