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Anisakis and Your Catch: How to Eat Mackerel, Horse Mackerel and Squid as Sashimi More Safely
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Mackerel, horse mackerel, squid and Spanish mackerel are all in season now, and they are all fish you want to eat as sashimi. The parasite to watch out for is Anisakis. Here is what anglers can do, based on guidance from Japan’s Ministry of Health, Labour and Welfare (MHLW).
Anisakis is a parasitic worm found in seafood. Eating larvae in raw or undercooked fish can cause food poisoning with severe stomach pain. The MHLW reported 337 cases of Anisakis food poisoning in Japan in 2024, and cases occur all year round.
This article summarises publicly available MHLW information for anglers. If you feel unwell, do not self-diagnose: see a doctor.
Which fish can carry it?
| Seafood | How common in angling |
|---|---|
| Mackerel (saba) | Common on sabiki rigs and in shore jigging |
| Horse mackerel (aji) | A sabiki and ajing staple |
| Sardine (iwashi) | Often caught in numbers on sabiki |
| Pacific saury | Mostly bought, not caught |
| Skipjack (katsuo) | Caught from boats and the shore |
| Salmon | — |
| Olive flounder (hirame) | A popular surf lure target |
| Tuna | — |
| Squid | Bigfin reef squid and others caught on egi |
These are the examples the MHLW lists. In other words, many of the fish you catch from piers and beaches can carry it. “I caught it myself, so it’s fresh and safe” is not a guarantee.
It can move from the guts into the flesh
Larvae live mainly on the surface of the internal organs. After a fish dies, they can migrate from the guts into the muscle. The MHLW also notes that larvae may already be in the flesh while the fish is alive. Gutting quickly helps, but it does not eliminate the risk.
Three points: freshness, inspection, freezing or cooking
| Point | What to do |
|---|---|
| 1. Freshness | Use fresh fish and gut whole fish quickly. Do not eat the internal organs raw |
| 2. Inspection | Look carefully for white, thread-like larvae and remove them |
| 3. Freezing or cooking | Freeze at −20°C for at least 24 hours, or cook to 70°C or above (or 60°C for 1 minute) |
Freezing
The MHLW guideline is −20°C for at least 24 hours. Many home freezers run at about −18°C, so check your freezer’s performance and allow extra time.
Cooking
Cook to 70°C or above, or 60°C for 1 minute. Simmered, grilled or fried fish cooked through is fine.
Common myths: these do not kill it
- Vinegar curing: vinegar-cured mackerel (shime-saba) does not kill Anisakis
- Salt
- Soy sauce
- Wasabi
Many people think shime-saba is safe, but the MHLW says vinegar curing is not an Anisakis measure. Combine it with freezing.
What anglers can do at the water
- Dispatch and bleed fish right away: the basis of freshness
- Chill thoroughly: use a slurry of ice and seawater in the cooler to cool the whole fish fast
- Gut early if you can: where local rules allow, gutting on site helps
- Take guts home to dispose of: do not dump them at the fishing spot, which can lead to closures
An angler’s biggest advantage is control over freshness from the moment the fish is caught. To shorten the time before larvae can move into the flesh: dispatch, chill and gut early.
At home: checking as you fillet
- Gut the fish as soon as you get home
- Check the belly meat around the organs especially carefully
- Slice thinly: larvae are easier to spot and to cut
- Remove anything that looks like a white thread (larvae are about 2–3 cm long)
- If you want sashimi, freezing first is the safest option
Anisakis lights
Anisakis larvae are said to glow under ultraviolet (black) light, and some tackle makers sell lights for checking fish as you fillet them. However, larvae deep in the flesh are hard to see, so a light alone is not enough. Combine it with freezing or cooking.
Suggested ways to eat each fish
| Fish | Safest | If you want it raw |
|---|---|---|
| Mackerel | Salt-grilled, simmered in miso, fried | Freeze first. Combine shime-saba with freezing |
| Horse mackerel | Fried, marinated (nanban), salt-grilled | Gut early and inspect well. Consider freezing |
| Squid | Tempura, stir-fried, simmered | Freeze first. Thin strips are easier to inspect |
| Spanish mackerel | Miso-marinated and grilled, meunière, fried | Freeze, then sear (aburi) |
| Olive flounder | Meunière, fried | Gut early and inspect well. Consider freezing |
Spanish mackerel is not on the MHLW’s list, but it is sensible to take the same care with all migratory fish.
If symptoms appear
According to the MHLW, most Anisakis food poisoning is gastric anisakiasis, with severe stomach pain. Allergic reactions such as hives or anaphylaxis can also occur, even without stomach symptoms.
- Severe stomach pain after eating sashimi or other raw fish
- Hives, difficulty breathing or other allergic symptoms
- Tell the doctor when and what you ate
There is no medicine that kills Anisakis. For the stomach, larvae are removed with an endoscope. Do not wait it out: get medical help quickly.
My take
Eating sashimi from your own catch is one of the best things about fishing. But that also makes freshness and preparation your responsibility. Remember the three basics: freshness, inspection, and freezing or cooking. Anglers can dispatch and chill a fish the moment it is caught and gut it early. When in doubt, cook it or freeze it first. Winter mackerel and horse mackerel are rich and delicious, so enjoy them safely.
Read next
- How to Ikejime and Bleed Yellowtail
- Japanese Horse Mackerel (Aji) Guide
- Daiwa Sea Cool Carry III Cooler
- Shimizu Port Tsuri Festa (15 November 2026)
ABOUT ME
Born in 1994. Originally from Hyogo Prefecture, I moved to Iwata City in Shizuoka Prefecture in search of the sea. I am an Enshunada surf angler who enjoys surf fishing. I am also active on YouTube, and my fishing grounds range from Irago to Iwata.
