you have to wait till the days come
No, you can't adopt any animals you rescue in Happy Aquarium or other games like Happy Aquarium.
Well, to adopt an animal for Happy Aquarium you would need to go to your friends' walls (that plays Happy Aquarium) and check if they have any recent animals for adoption, because if it isn't recent, it might already be adopted.
You have to adopt it off a friend's wall
yes
if your friend found any lost turtle, you will have a chance adopt it for free. source : http://www.yayeasy.com/happy_aquarium/happy-aquarium-baby-sea-turtle-adopt/
there are turtle, squid and penguin available for adopt, if your friend found any lost orphan by click on the adopt you will get a chance adopt orphans sources: http://www.yayeasy.com/happy_aquarium/happy-aquarium-baby-sea-turtle-adopt/
if your friend found any lost turtle, you will have a chance adopt the turtle for free. sources : http://www.yayeasy.com/happy_aquarium/happy-aquarium-baby-sea-turtle-adopt/
if you log in for a certain number of days you get one
when your friend found an turtle, and he/she post it publish it to ask someone to adopt the turtle, first person clicking on adopt will get turtle in you aquarium.anyway i read information fromhttp://www.yayeasy.com/2009/10/happy-aquarium-baby-sea-turtle-adopt/you can try go to the website, they frequently updates the latest tips for happy aquarium
there are turtle, squid and penguin available for adopt, if your friend found any lost orphan by click on the adopt you will get a chance adopt orphans sources: http://www.yayeasy.com/happy_aquarium/happy-aquarium-baby-sea-turtle-adopt/
Nope
yes, you have to adopt one and save your pearls for the other