Well, considering the fact that mermaids are a mythical creature and not real, no. Dolphins do not hang out with mermaids, nor would they if they were real. Dolphins are smart enough that they have better things to do than hang around with a bunch of sea-chicks all day.
dolfins are mammals because they give birth and they need to breathe air.
yes
ys
A pod.
4 fins
No mermaids and sea urchins are different creatures. However if a very young mermaid were to hang about the sea lanes not doing anything in particular then she could be termed a 'sea urchin' if we were to take the language loosely enough.
Yes. There freaking Cute as heck.
Dolphins do not sleep.
its dolphin not dolfin and no
There are. dolfins, seals, whales.
There are no actual mermaids...
No. Mermaids are not real and there are no spells to make people into mermaids.