The kun'yomi reading is used for the 魚 (so it's さかな) and the kun'yomi reading is used for 屋 (や). You'll have to use the reading of 魚 from the vocabulary from a couple levels ago to remember the reading of this one.
We went to buy splendid red bream at the fish store.
This fish shop floor is very slippery, so be careful.
The fish shop gave me a 100 yen discount.