Final answer:
Clownfish are known as protandrous hermaphrodites, being able to change their sex from male to female in response to social cues within their hierarchy, which ensures continuation of the species.
Step-by-step explanation:
Clownfish are protandrous hermaphrodites, which means they have the ability to switch their sex from male to female. Protandry is a term used when an individual is born as a male and later changes to a female. This phenomenon ensures that if a dominant male perishes, another male in the community can transform into a female and continue the reproductive process, which is crucial for species survival in their specific social structures. An example of this is seen in some oyster species, where they are born male, grow in size, and then switch to female to lay eggs. Another term for the reverse process, where an individual starts as a female and then becomes a male, is protogyny.
Clownfish live in groups with a strict hierarchy, which is maintained by this ability to change sex. In their groups, there's typically a dominant male and several smaller females. If the dominant male dies, the largest female will change sex to become the new dominant male. This adaptation is an evolutionary strategy that maximizes reproductive success in their environment.