• The male cardinal fish opens its mouth as if yawning to attract sexual partners. Once the female's eggs are laid and fertilised the male keeps them in his mouth for a week, so by swimming around with his mouth open the male is advertising that he's a "great catch" and can hold all the eggs (sorry about the pun).
• Male elephant seals can lose up to 1000 kilograms when fighting with other seals for the privilege of mating with the 'best' female (the seal prom queen). The battles can continue for days with little or no resting or feeding time for the fighters.
• After the wallaby gives birth to a joey she is ready to conceive just 8 hours after the joey reaches the pouch.
• Male wallabies are capable of making a barrier of semen over the female's vagina after sex. The barrier is impenetrable and ensures that the female will give birth to the joey of the first male wallaby who gets to her.


• Clownfish, like some other varieties of ocean life, are capable of changing from male to female and vice versa. If the dominant clownfish male sees an unguarded egg nest, he can morph into a female and take on the eggs as his/her own.
• The "male" seahorse (seahorses are also capable of switching gender) carries fertilised seahorse eggs on its belly until it gives birth, making them resemble a human pregnant woman to some effect.
• Male dragonflies use "suckers" to attach themselves to their female partner after mating. This ensures she can lay her eggs safely and no other males can attack or impregnate her during that time.
• The largest penis in the animal kingdom is that of the blue whale, at 11 feet. The mosquito penis, on the other hand, is only 1/100th of an inch.
• The most arousing time of day and year for a male human is the early morning, in autumn.

Facts from ABC documentary "Sperm Wars".