"marine invertebrates" was incorrect.... should it be?

I'd typed in 'currencies' but says incorrect, I'd award myself a point for that. And another one are indeed marine invertebrates which should give you one point. So for me, instead of 6, I should get 10.

It didn't accept mollusc either but uses the word in the description. Clearly a duff link.
I think they've put 'molluscs' and 'currency' rather than 'mollusc' and 'currenc' which would incorporate both.

Who really says marine invertebrates instead of molluscs?

Yes I did put the full version of the words instead of what Tbone said.