Fish and seafood species, freshness, safety, storage, nutrition, buying cues and cooking techniques.
Fresh shrimp should smell mild and feel firm. A sour, rancid, strongly fishy or ammonia-like odor is a clear warning, and pronounced sliminess or mushiness adds concern. Sensory checks cannot extend an expired refrigerated storage window.
Cooked shrimp should generally be used within 3–4 days in a refrigerator at 40°F (4°C) or below, assuming it was chilled promptly. A normal smell on day five does not extend that window because pathogens do not always cause obvious spoilage.
Cooked salmon can be refrigerated for 3–4 days at 40 °F (4 °C) or below under USDA guidance for cooked fish and seafood. Refrigerate it within about two hours after cooking and freeze portions early if they will not be used within that window.
Salmon color varies too much to be a precise safety test. FDA guidance uses 145°F (63°C) for finfish; measure the thickest part with a food thermometer. Opaque flesh that separates easily is a useful fallback cue when you cannot measure.
Lean white fish dominate the low-calorie end. USDA references put raw flatfish such as flounder/sole at about 70 calories per 100 g, haddock at 74 and Atlantic cod around 82. Preparation can change the final calorie density more than a few places in the ranking.
USDA recommends using frozen raw fish within about 3–8 months for best quality and cooked fish within about 3 months. Fish kept continuously at 0 °F remains safe longer, but flavor and texture gradually decline.
Mackerel, salmon, herring and sardines are among the common higher-fat fish. Representative cooked or canned references often provide roughly 10–18 g fat per 100 g, compared with around 1–2 g in many lean white fish. A substantial share is unsaturated fat, including EPA and DHA.
Fresh fish is highly perishable. USDA recommends keeping raw fish and shellfish at 40°F (4°C) or below for only 1–2 days before cooking or freezing. FDA similarly says seafood that will be used within two days should be kept on ice or in a clean refrigerator at 40°F or below; otherwise, freeze it.
USDA recommends using cooked fish and other seafood within 3–4 days when refrigerated at 40 °F (4 °C) or below. Refrigeration slows bacterial growth but does not stop it, so prompt chilling matters as much as the calendar.
Smell is one of the most useful signs: FDA says fresh fish should smell mild and fresh, not strongly fishy, sour, rancid or ammonia-like. Flesh should be firm and spring back when pressed. In fillets, darkening, discoloration or drying around the edges indicate loss of freshness, although no home test replaces correct cold storage.
Yes. Salmon skin is edible. When cooked well it can become crisp and contains some of the fish's fat. There is generally no blanket safety reason to remove the skin from commercial salmon, although locally caught fish from waters with contaminant advisories can require different guidance.
Among commonly eaten fish, salmon, herring, sardines and mackerel stand out for EPA and DHA. NIH lists about 1.83 g EPA+DHA in 3 oz (85 g) cooked farmed Atlantic salmon, ~1.71 g in Atlantic herring, ~1.19 g in drained canned sardines and ~1.02 g in Atlantic mackerel.