Did Georgian ever have a native word for “dolphin”?

Question

During my time in Georgia one word came to puzzle me and I'm still thinking about it:

დელფინი (delp'ini) "dolphin"

Wiktionary says this comes from Greek via Russian.

The thing is Georgia is on the Black Sea which has plenty of dolphins so why wouldn't they have their own word since the times before contact with Greek civilization? Georgian is pretty resistant to borrowing basic vocabulary. There's a native word for "whale" for instance.

Now loanwords are not as common in Georgian as in English, but they're not really rare. They are however mostly for modern/introduced concepts but Georgian is a pretty ancient language, it hasn't really moved, and dolphins have always existed in the world the Georgians inhabit.

I have a couple of theories but they're unconvincing and I haven't been able to find any information:

• There was once a native word but it fell out of use.
  ^{(It's not in any of the bilingual dictionaries I've been able to find.)}
• Dolphins were considered to be fish, like elsewhere, until relatively recently with the study of biology, taxonomy, etc.
  ^{(But different kinds of fish still have different names and dolphins are pretty different.)}