turtle ? no , i think it is not, it might be a bird according ur words, it's called "凤凰",
hm, yes, these 2 things have different meanings, hm, it is chinese culture.
long long before,dragon and the mystical bird are 2 of chinese tribal symbol, they both means peace and bumper harvest for tribal, hm, and what about this fish, it must be carp, yes, it means lucky in China culture, why ? because of "鲤鱼跳龙门", what this sentence meaning? 龙门 means the house' door, witch family gains high achievement, and it also usually means the door of fine goal, in the eyes of the chinese people, carp can jump into this door, means u also jump into this door, also gain high achivement, so, carp usually means good lucky,
so, now u can get what meaning of a fish, a dragon and a mystical maybe a turtle, these three thing together. if your tribal is peace and bumper harvest, u also happy.
but what about 3 fish together? it is not a simple together, i think their head is together, what this means ? together means 1, and the number of fish is three, it means "一生三", 1 means 1, but the 3 is not only 3, it means many, quite a lot,
so, what is this thing called? "三鱼同首", this 1 means u, and this 3 means your children, and your grandchild, hm, it is a good picture of a family, why use fish means child? because of it's fish scale, so much so that u can't count, it means your family exist in the world everywhere, forever, chinese always like child and grandchild, the more the better, so now, u can also know what 3 fish together means,"三鱼同首".
u can choose the one u prefer