It marked me wrong for saying "THE fish has bones"
Coud it be a general meaning; Like all the fish have bones?
If, yes, Fish have bones possible, would be possible here too.
That would be pisces + habent, where piscis + habet is singular. So that's a no.
Although, to be honest, the sentence given as a translation is already general. ;)
Volgav vitsenanieff nivya kevach varatsach.
Yes. I agree. But, we are getting caught up on what it means, rather than what is written. We are thinking figuratively, not literally.
Leaving out the particle shouldn't be a problem
No, we need either "the" or "a", because otherwise it'd be "fish have bones", which would mean the fish are plural, whereas the Latin is clearly singular.