Can Octopus Eat Salmon? Occasional Marine Fish or Poor Staple?

Octopus are carnivores that do best on a varied marine diet. In the wild and in managed aquarium settings, they commonly eat crustaceans and other marine invertebrates, with fish included as part of a mixed menu rather than the whole diet. Aquarium husbandry guidance for giant Pacific octopus notes that raw seafood such as herring, smelt, squid, fish fillets, shrimp, and clam meat can be used, but it also stresses that a significant portion of the diet should come from crustaceans or other lean protein sources.

That matters because salmon is relatively fatty compared with many common octopus feeder items. In one aquarium care manual, Alaskan salmon is listed at about 7.94% fat, while blue crab is about 0.77%, shrimp about 0.95%, squid about 1.6%, and clam about 0.87%. A newer aquarium diet review also found that many captive octopus diets were higher in fat than recommended, even when protein levels were appropriate. So salmon can fit as an occasional food, but it is usually a poor staple if fed too often.

For pet parents, the practical takeaway is balance. A small piece of plain salmon may be acceptable now and then, especially if your octopus already eats a broad marine menu. But if salmon becomes the main protein, the diet may drift away from the leaner, more varied prey profile octopus are adapted to. Your vet can help you decide whether your individual species, age, body condition, and feeding history make salmon a reasonable occasional item.

There is no one-size-fits-all salmon portion for every octopus species, because feeding needs vary with species, age, water temperature, activity, and reproductive status. Aquarium guidance for giant Pacific octopus estimates daily intake around 2% of body weight, though many institutions feed several times per week rather than every day. That total intake should come from a varied diet, not from salmon alone.

A practical conservative approach is to keep salmon as a small part of the weekly menu rather than a routine main course. For many pet octopus, that means a bite-sized piece or one small feeding portion offered occasionally, then rotating back to leaner prey such as crab, shrimp, clam, mussel, or squid. If your octopus is small, the piece should be correspondingly very small and easy to handle.

Offer only plain marine salmon with no salt, smoke, seasoning, breading, oil, or sauces. Remove leftovers promptly so the tank stays clean. If you are considering raw fish regularly, ask your vet about food safety, sourcing, and whether freezing protocols or alternative feeder items would be safer for your setup.

Watch closely after any new food item, including salmon. Concerning signs can include refusal to eat after previously feeding well, dropping or rejecting the food repeatedly, unusual lethargy, poor grip strength, abnormal paling or persistent dark stress coloration, bloating, regurgitation, or rapid decline in water quality from uneaten food. These signs do not prove salmon is the cause, but they do mean your octopus needs prompt attention.

Diet-related trouble can also build more slowly. If salmon is fed too often, your octopus may still eat eagerly while the overall diet becomes too narrow or too fatty. Over time, you may notice inconsistent appetite, poor body condition, reduced activity, or trouble maintaining normal behavior. Because octopus health can change quickly, subtle shifts matter.

See your vet immediately if your octopus becomes weak, stops responding normally, cannot coordinate movements, or has repeated vomiting or severe appetite loss. Also act quickly if the tank becomes fouled after feeding, since water quality problems can worsen illness fast in aquatic species.

Better staple choices are usually leaner, varied marine foods that more closely match the prey profile used in aquariums and seen in nature. Good options often include crab, shrimp, clam, mussel, squid, and small marine fish such as smelt or herring when appropriate for the species and your vet's guidance. These foods help create variety while avoiding overreliance on one richer item.

Crustaceans are especially useful because many octopus naturally target them, and aquarium references repeatedly place crabs high on the preferred-food list. Mollusks and squid can also add texture and enrichment. Rotating among several marine items is often more helpful than searching for one perfect food.

If you want to use fish, leaner marine fish are usually a better routine choice than salmon. Ask your vet which feeder items are realistic for your octopus species, tank conditions, and budget. A thoughtful feeding plan can be conservative, practical, and still nutritionally sound.