Barred knifejaw

The Barred Knifejaw is a rare fish found in the ocean and sells for 5,000 Bells at Tom Nook's store. It appears all day in spring and summer and is black with seven white stripes. Its shadow size is small/medium, around the same size as the squid, octopus, and dab. The fish, along with all other ocean fish, appears in the back tank when donated to the Museum, and is considered to be quite a hard fish to catch, as Blathers will tell you when you donate it.

In Animal Crossing
When the player donates it in Animal Crossing, Blathers will say: "Hoo! Indeed, WOO hoo! A barred knifejaw, I believe. Hoo!  Hoo, I say!  Just look at this magnificent creature!  Truly, a king among edible aquatic beasts of the world! Tuna, scallops, oysters, lobsters, salmon, halibut, crabs, barnacles... Well, maybe not barnacles... One would have to be in dire straits indeed to consume a few of those jagged beasties!"

"Now then, what say we set this chap up in his new home, eh wot?"

In Wild World
When the player donates it in, Blathers will say:

", the very fact that you caught this tells me that you are quite a fisher! Oh, a recipe for Barred Knifejaw? I'd recommend putting it in a broth. Grilling makes the flesh rather tough, eh wot?"

In City Folk
When the player donates it in City Folk, Blathers will say:

"Hootie hoo, look at you! You've hauled in a star catch this time! Indeed, simply marvelous work!' The Barred Knifejaw is a clever fish that, it's said, requires some rather fancy fishing to catch. Their monotone color scheme certainly paints them as smart, sensible fish in my eyes, eh wot?"

In New Leaf
In New Leaf an information board in the aquarium will list information about this fish.

"Barred knifejaws stand out thanks to the seven stripes adorning their white bodies. Their natural curiosity and strong pull make them a popular target of anglers, but they're no easy catch. They have strong teeth that allow them to make short work of sea creatures with tough shells. This means that both urchins and mollusks need to be careful, lest they become meals for these fish."

Further information
The striped beakfish, also known as the barred knifejaw, is a tropical fish, generally found in coral reefs and around Japan. It has been seen in Hawaii, but only once. It normally eats invertebrates.