"Look and Feel" to Choose Fresh Fish
Look: Fresh fish have shiny skin, complete and flat scales, red gills, and prominent, clear eyes. Unfresh or spoiled fish have dull scales that are loose, sunken and dim eyes, gills that are dark red or grayish-white, a swollen belly, and a protruding anal vent.
Feel: The back of a fresh fish is firm and elastic; when pressed with a finger, the indentation quickly returns to normal. The belly is not swollen, and the body surface has a small amount of transparent, smooth mucus. The back of an unfresh or spoiled fish is soft, and the indentation from a finger press is slow to return to normal.
Two Looks and One Test to Choose Fresh Shrimp
Two Looks: Fresh shrimp have firmly connected thoracic and abdominal segments; their body surface is transparent with a bluish tint, dry, and clean. Unfresh shrimp are red in color.
One Test: Fresh shrimp are plump, full of moisture, elastic, and have good tension when stretched or bent. Unfresh shrimp are soft, sticky, limp, have poor tension, and have a strange odor.