Please help me ID cardinalfish

[showmebutterfly]

It's a type of cardinalfish and it's black and white striped. The store has it labeled as a picket fence cardinal, but from my research that is not correct.

Possibilities that I've come up with - blackstriped, four-lined, Sydney, Cook's - these all look sort of like it - at least from the Google pics I've found. I'm just hoping somebody can help me with a positive ID.

Please and thank you to anyone that can help!

 

[whosurcaddie]

Doederlein's or Four-Stripe Cardinalfish.

 

[showmebutterfly]

Doederlein's or Four-Stripe Cardinalfish.

Thank you!