Gender and sexuality in animals is very different to humans. There are some interesting animals with traits that you may be interested in;
– Clown fish are a matriarchal social group (women at the top), however when she dies her mate will change sex from male to female so he can then lead the family.
– Spotted Hyena females have a pseudo-penis, which they give birth through.
– Some invertebrates, such as snails, termites and banana slugs, do not really have a gender until they mate. Snails are hermaphrodites and have ‘love darts’ that they fire at each other containing genetic material; other invertebrates fight and try to stab each other (who ever gets stabbed becomes the female ); also, some will fight to remove one-anothers male sex organs and if they are removed, they become a female.
– In seahorses, the males are the ones to give birth!
Nature is weird and wonderful.
Well, yes you can – see the sex changing fish on the recent series of Blue Planet. And most snails are hermaphrodite. Actually, perhaps the majority of all plants and animals are hermaphrodite – it is just from our human- and vertebrate-centric point of view that makes us think having separate sexes is the norm
To add to what others have said: there are some animals that would pretend being of opposite gender. This is usually done to achieve certain goals, for example, males can pretend being female so that they would not be beaten up by other males who are competing for female attention. However, this can also lead to being subjugated to a different kind of abuse from said males.
Great answers above. I don’t have anything to add really except that as far as we know sharks aren’t what you could call gender fluid. They seem to be born either a male or female and stay this way throughout their lives. That said, when it comes to questions of gender and sexuality there is really so much still to learn…in humans and other animals!