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/
Your happy aquarium neighbors post them for adoption. You can also get squids, and penguins from adoption.
No check some of the other Q.A. about H.P.
You can only adopt male baby sea turtles and female squids, but if you want the female sea turtle you can buy it for 23 pearls or the male squid for 623 coins. Hope this helps! (Oh and if you were looking for more interesting colors, you can mate the male and female squids and possibly get a hot pink squid or golden, or if you mate the turtles you can get a gold one.)
no, you are only able to mate same types of fish or turtle
no its just random
Hot pink and gold
Another golden squid.
You have to click "adopt a baby squid" when one of your friends posts it up for adoption.
yes, you have to adopt one and save your pearls for the other
Now the Happy Aquarium store is offering blue male squids for 623 coins. It is under the Special star tab. You can mate them for 312 coins. You cannot adopt them, only buy.
You can get a purple, blue, hot pink, and golden squid. You can get the golden and hot pink aquid by mating the blue and purple squid.
you get a different colored baby sea turtles, at the moment i only got rainbow sea turtles from mating them. but i saw some say's that there are more variety of colors.