Today's wonder
Why do some animals change gender during their lives?
a real page from the book
Some animals change gender because, in their group, a different body can make reproduction work better. In clownfish, the largest fish becomes female; in some reef fish, a large female may become male. The change follows size, rank, and social signals, not a random whim.
The animal already carries instructions for both kinds of reproductive body. Hormones and genes shift which instructions are active, and organs and behavior change over weeks. The term sequential hermaphroditism names this one-after-the-other pattern in animals such as clownfish, wrasses, and parrotfish.
Wonder words
- hormones
- genes
- clownfish
- territory
Try it out
Line up family objects by size, then imagine which one would take over a reef group if the biggest disappeared.
Read the whole picture book
Watercolour scenes, straight answers, about three minutes cover to cover. Free today, no account needed.
Read the book — free todayAlso free today
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Keep wondering
Yesterday's wonder: Why do we have time zones?
And the next question?
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