animalworld:

MALE SEAHORSE giving birth / see a short video here
 Hippocampus sp.
©Lazaro Ruda

By Request - In sea horses, the male become pregnant.  Their mating involves the female inserting her oviduct into the male’s brooding pouch.  She does this several times for short intervals to avoid exhaustion.  In between the female rests while the male contorts himself to try to get the eggs in place in his brood pouch.  After completion the male moves away and attaches himself by his tail to a nearby plant.  The female moves away and waits for her oviduct to recede.  The oviduct usually recedes within a few hours.  The eggs are fertilized and hatch in the male’s pouch.  The size of the sea horse brood varies within sea horse species.  Some species’ broods are as large as 200 while others are as small as 8.

The males are pregnant for several weeks before giving birth to their brood .  When they prepare to give birth, the pouch extends to an almost spherical shape.  The male also undergoes muscular contortions - a forward and a backward bend - that last for about ten minutes.  then in an explosive action the brood leaves the pouch.  After the last young sea horse has left, the pouch returns to its normal position, which usually takes about an hour.  Males are ready to re-mate within a few hours of giving birth. Source

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