Saltwater · Autumn and spring peaks in South China estuaries and surf; present most of the year

Fourfinger Threadfin

Eleutheronema tetradactylum

The fourfinger threadfin — 'wu yu' or 'ma you' in the south — is the silvery prize of Guangdong, Fujian, Taiwan and Hainan surf and estuaries, a strong, clean-running fish identified at a glance by its four free pectoral filaments.

Seasons · Peak

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Fourfinger Threadfin — Photo: BEDO (Thailand), CC BY-SA 4.0 — Wikimedia Commons

Identifying features

Silvery, moderately deep body with a blunt rounded snout and eyes set far forward
FOUR free, thread-like pectoral rays hanging below the pectoral fin — the unmistakable ID anchor
Small mouth on the underside of the head; lower jaw with fine teeth
Two widely separated dorsal fins; tail deeply forked with long lobes
Scales large and smooth; back grey-green, belly bright silver

Habits

Frequents estuaries, surf zones and sandy shallows of the South China coast, entering brackish water freely
Feeds on shrimp, small fish and crabs, rooting in sand and mud with its sensitive filaments
The filaments are feelers — the fish 'tastes' the bottom as it swims
Runs in small schools; larger fish are often solitary
A strong, fast fighter on light tackle and a premium table fish in Chaozhou and Cantonese cooking

Distribution

Regional coverage expanding

Where to find them

Surf beaches of Guangdong, Fujian and Hainan
Estuary mouths and brackish channels in Taiwan and Fujian
Sandy shallows near river plumes after rain

Where they live

Estuaries and river mouthsSurf beachesSandy coastal shallows

How to catch them

Surf casting from beaches Shore

Rig: Surf rod, running-sinker rig with live shrimp or worm cast beyond the breakers

Bait/lure: Live shrimp, beach worms, shrimp pieces

Key tip: Fish gutters and holes along the beach at dawn and on a rising tide.

Boat live-shrimp fishing in estuaries Boat

Rig: Light boat rod, free-lined or lightly weighted live shrimp drifted along channel edges

Bait/lure: Live shrimp

Key tip: Let the shrimp drift naturally with the current — threadfin spook at heavy, dragging rigs.

Best baits & lures

Live shrimpSandworms and beach wormsSmall live fish and shrimp pieces

Techniques for Fourfinger Threadfin →

Baseline setup

Rod: Surf rod or light boat rod
Line: 15-25 lb braid or mono
Terminal: Running-sinker rigs, circle hooks, live-shrimp rigs

Recommended gear for this species

Rod · Best value

9' 5-weight fly rod outfit

≈ US$180-260

Covers chironomid lakes and small rivers with one setup.

Flies · Budget

Chironomid assortment (30 patterns)

≈ US$25-40

Chironomids are 60% of a lake rainbow's diet in spring.

Picks come from our rule library — never paid placements. Prices are guides; affiliate links may earn us a commission.

Typical size

Common 20-35 in and 3-10 lb; large fish to about 6 ft in the wider Indo-Pacific

On the table

Excellent — a top-grade fish in southern China; large fish are cut into steaks, prized for firm, sweet flesh.

Similar species

Flathead Grey MulletFlathead grey mullet has a broad, flattened head, small underslung mouth and NO free pectoral filaments; the threadfin's four hanging threads separate it instantly

Japanese SeabassJapanese seabass is a perch-like predator with a protruding lower jaw and spotted juveniles, and no pectoral filaments; threadfin has a blunt underslung mouth and four free rays

Regulations vary by area and can change in-season — always check the official rules for your area before you fish. Regulations guide →

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