Hi,
I am not sure the 筍殼魚 you are referring to in this article is the same 筍殼魚 in New Zealand, but it certainly looks like the one in New Zealand.
筍殼魚's English name is Blue Cod and it's from sea water, not a fresh water fish. Blue cod is one of the fish has limited by the quota system in NZ. It's very suitable for steaming.
Please let me know if anyone has more information about 筍殼魚. Is it the same one in NZ? Is the term 筍殼魚 from Hongkong? Sounds like it though.
Cheers
Barry