Bait-cage casting from a Breakwater / Pier
Dogtooth Tuna: Use current lines and birds to anticipate the school. The rig is heavy, so check behind before every cast.
Waters: Okinawa & Nansei Islands, East China Sea & western Kyushu
Fish
Dogtooth Tuna イソマグロ
Gymnosarda unicolor ・ Scombridae (Mackerels, Tunas, and Bonitos)
Catch season
- Catchable
- Peak
Months for Dogtooth Tuna are a broad Japan-wide guide and shift with region, temperature and conditions; prefer local reports and rules.
About
It cannot breathe once it stops swimming, so it keeps moving with its mouth open. Some members of this unusual group of fish can hold their body temperature above that of the surrounding seawater. Found around Okinawa and the Nansei Islands, in the East China Sea, and along the west coast of Kyushu.
Basics
- Scientific name
- Gymnosarda unicolor
- Family
- Scombridae (Mackerels, Tunas, and Bonitos)
- Japanese name
- イソマグロ
- Kana
- いそまぐろ
- Waters
- Okinawa & Nansei Islands, East China Sea & western Kyushu
- Size
- 44 cm (max 80 cm)
- Time of day
- Dawn, Dusk
- Depth (tana)
- Surface to mid-water, setting float depth to the travelling school.
How to catch it
Kit for this fish
Bait-cage casting kit ・ Kit total ¥26,000–68,000
- 4.5 m distance-casting float rodDistance-casting float rod rated for a bait cage and float. ¥9,000–30,000AdFind on AmazonFind on Rakuten
- Spinning reel, size 4000-5000For shore jigging. A smooth drag under a running fish matters more than anything here, so this is not the place to economise. ¥10,000–35,000AdFind on AmazonFind on Rakuten
- Nylon line, 5-gou (about 20 lb)Main line for live-bait fishing, giving margin once something large is on. ¥800–2,500AdFind on AmazonFind on Rakuten
- Distance bait-cage and float rigCage, float and boom assembly; keep the weight within the rod rating. ¥1,200–4,000AdFind on AmazonFind on Rakuten
- Okiami krill (raw or boiled)The hook bait for float and fukase fishing. Boiled stands up to bait thieves; raw gets more bites. ¥400–1,200AdFind on AmazonFind on Rakuten
- Groundbait mix for chummingPowder mixed with krill so the chum throws well. Changing its density and stickiness delivers the chum to the depth you want. ¥500–1,500AdFind on AmazonFind on Rakuten
- Rope bucket for drawing seawaterUsed to rinse hands and chum and to keep fish alive. It is also how you leave the pier clean. ¥800–2,500AdFind on AmazonFind on Rakuten
- Cap and polarised sunglassesAlso safety equipment, protecting your eyes from a flying rig. Polarised lenses additionally let you read the bottom. ¥2,000–20,000AdFind on AmazonFind on Rakuten
- Life jacket, adult (Japan Craft Inspection approved)The first thing to buy, and worn on piers, rocks and boats alike. Boat fishing requires the government-approved type marked with the cherry-blossom stamp. ¥5,000–20,000AdFind on AmazonFind on Rakuten
The heavy rig demands head and eye protection plus generous casting clearance.
Product links may be affiliate links. Prices move, so treat the ranges as a guide.
Handle with care
This fish is dangerous to handle bare-handed.
Histamine
Warm storage raises histamine-poisoning risk. Chill the catch immediately with ample ice; cooking is not a remedy.
Killing and carrying your catch — the taste is decided at the pier, not the kitchen
Eating
If retained for food, chill immediately and follow established local handling with thorough cooking.
Best eating: September–December
Rules
Before fishing, check prefectural fishery rules, regional size and season limits, protected areas, and harbour or charter retention rules.
Closed seasons and size limits — how to find the numbers, which differ by prefecture
This article organises general information and is not legal advice. Rules differ by municipality and by fishery cooperative, and they change. Always check the current rules for where you are going.
Other fish taken the same way
Other fish from the same kind of place
Seasons, sizes and eating quality are general guides. Rules change, so check the latest prefectural, fishery-cooperative and site rules before fishing. This app provides general information, not legal advice.