Fish
Plotosus japonicus ・ Plotosidae (Eeltail Catfishes)
It turns up as a by-catch in night and bottom fishing from piers in summer and autumn. The juveniles swim in a dense black ball known as a gonzui-dama; if you see one, keep your rig away from it.
A saltwater catfish that gathers in the shadows of rocks. Juveniles form dense balls known in Japan as "gonzui-dama." The dorsal and pectoral fins carry venom.
Nobody fishes for it. It hooks up on the bottom during night surf and hole fishing with worm or cut bait. When you get one, do not swing it up: put it on the ground first and work with pliers. On a dark pier people step on them, so always know where it is.
The dangerous by-catch you are most likely to meet fishing worm at night: a black body with yellow lengthwise stripes and barbels around the mouth. In the dark, one left at your feet is one you will step on, so always know where it is, and either take it away or put it back in the sea.
Waters: Sea of Japan, Southern Pacific coast, Seto Inland Sea, East China Sea & western Kyushu, Okinawa & Nansei Islands
Chonage starter kit ・ Kit total ¥11,000–24,000
A compact rod travels by train. Jarime is the easiest bait to handle.
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This fish is dangerous to handle bare-handed.
Venomous spines
The first spine of the dorsal and each pectoral fin carries a powerful venom; a sting causes intense pain lasting hours to days, and the venom remains active in a dead fish. If stung, wash the wound, immerse it in water as hot as you can bear (around 45C), and always seek medical care. Look for a catfish-like black body with yellow lengthwise stripes and barbels around the mouth. Sometimes the safest option is to cut the line and lose the hook, but never leave the fish on the ground: take it away or return it to the water.
Dangerous fish and animals — what to do when you are stung or bitten
Because handling the venomous spines is hazardous, this guide does not recommend treating it as food.
Check the local fishery regulation. Leaving a dangerous fish on a pier injures other anglers and is a direct cause of spots being closed to fishing.
Etiquette at the water — how a spot stays open
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.