Can I eat fish cooked to a lower temperature if it looks done?

Visual cues alone are not enough to guarantee safety. The only reliable way to know fish has reached a safe temperature is to measure it with a food thermometer. If it looks done but reads below 145°F, continue cooking until it reaches the target.

Do I need to rest seafood like meat after cooking?

Unlike large cuts of beef or pork, seafood does not need a resting period. Carryover cooking is minimal, so you can serve it immediately once it reaches 145°F. For thick fillets or whole fish, you may notice a few degrees of carryover, but this is not a safety concern.

What should I do if a clam or mussel does not open during cooking?

Discard any bivalve that remains closed after cooking. A closed shell can indicate the animal was already dead before cooking, which increases the risk of spoilage and bacteria. Do not force it open; throw it away.

Is it safe to eat raw fish like sushi if it has been frozen?

Freezing kills parasites, which is why sushi-grade fish is often frozen before serving. However, freezing does not kill all bacteria. For people with healthy immune systems, raw fish from a reputable source is generally considered safe, but the FDA still recommends cooking to 145°F for those at higher risk, including pregnant women and older adults.

Safe Internal Temperature for Fish and Shellfish: A Glossary of Doneness Cues

Why Temperature Matters for Seafood

Seafood carries a higher risk of foodborne illness than many other proteins because it is often eaten raw or lightly cooked, and because the animals themselves can harbor bacteria, viruses, and parasites from their environment. Cooking to a safe internal temperature destroys these pathogens, making the food safe to eat.

Unlike meat, where doneness is a matter of preference, seafood has a clear safety threshold. The U.S. Food and Drug Administration (FDA) recommends cooking most seafood to an internal temperature of 145°F (63°C). This single number applies to fish, shrimp, lobster, crab, and scallops, though some exceptions and nuances exist.

This glossary defines the key terms you need to cook seafood safely, from the official temperature targets to the visual signs that tell you the food is done. Use a food thermometer as your primary tool, and treat visual cues as a backup check.

Seafood Type	Minimum Internal Temperature
Fish (all finfish)	145°F (63°C)
Shrimp, lobster, crab	145°F (63°C)
Scallops	145°F (63°C)
Clams, mussels, oysters	Cook until shells open; discard unopened

A digital instant-read thermometer inserted into a white fish fillet on a cutting board

The 145°F Standard for Finfish

For all finfish, including salmon, tuna, cod, halibut, and tilapia, the FDA sets a minimum safe internal temperature of 145°F (63°C). Insert the thermometer into the thickest part of the fish, away from any bones, and wait for the reading to stabilize.

Some chefs prefer to cook fish to lower temperatures for texture, especially for tuna or salmon served medium-rare. However, the safety recommendation is clear: 145°F is the threshold that guarantees destruction of harmful bacteria and parasites. If you choose to serve fish at a lower temperature, you accept a higher risk of foodborne illness.

One exception to the 145°F rule is for fish that has been previously frozen to kill parasites, such as sushi-grade tuna. Freezing at -4°F (-20°C) for 7 days or at -31°F (-35°C) for 15 hours destroys parasites, but it does not eliminate bacteria. Even then, cooking to 145°F remains the safest choice for anyone with a compromised immune system, pregnant women, or older adults.

Shellfish: Shrimp, Lobster, Crab, and Scallops

Shrimp, lobster, crab, and scallops should also reach 145°F (63°C) at the center. For shrimp, this means the flesh turns opaque and the tail curls into a loose C shape. For lobster and crab, the meat becomes firm and opaque, with a color change from translucent to white or pink.

Scallops are done when the flesh is opaque and firm to the touch, and the internal temperature reads 145°F. Be aware that scallops continue to cook briefly after being removed from heat, so pull them slightly before the target if you prefer a tender texture, but verify they still reach the safe minimum.

Shell-on shellfish, like crab legs or lobster tails, can be trickier to measure because the shell insulates the meat. Insert the thermometer through the shell into the thickest part of the meat, or remove the meat from the shell and measure directly. When in doubt, cook a little longer rather than risk undercooking.

Bivalves: Clams, Mussels, and Oysters

Clams, mussels, and oysters are different from other shellfish because they are often cooked in their shells. The standard safety test is not a temperature reading but a visual one: the shells should open during cooking. Discard any bivalve that remains closed after cooking, as it may have been dead before cooking and could harbor bacteria.

Once the shells open, the meat inside is considered safe to eat, though you can also check the internal temperature of the meat if you prefer. The FDA recommends cooking bivalves until the shells open, which typically takes 5–10 minutes depending on the method and quantity.

For shucked bivalves (meat removed from the shell), treat them like other shellfish and cook to 145°F. Raw oysters on the half shell are a popular delicacy, but they carry a risk of Vibrio bacteria, which can cause serious illness. People with liver disease, diabetes, or weakened immune systems should avoid raw bivalves entirely.

Visual Doneness Cues: The Flake Test and More

The flake test is the most reliable visual cue for fish. Insert a fork at the thickest point and gently twist. If the fish flakes easily, separating into opaque segments, it is done. Undercooked fish appears translucent and resists flaking, while overcooked fish becomes dry and falls apart too readily.

Color changes also signal doneness. Raw salmon is deep orange-red and turns lighter pink when cooked. White fish like cod or halibut go from translucent to pearly white. Shrimp turn from grayish-pink to a bright coral color, and their flesh becomes firm. These cues work well alongside a thermometer, but they are not a substitute for an accurate temperature reading.

The FDA also notes that fish should be cooked until the flesh is opaque and separates easily with a fork. This is the same guidance used by restaurants and food safety inspectors. Combining the flake test with a thermometer reading of 145°F gives you the highest confidence that the seafood is both safe and properly cooked.