Saltwater · Best April to November in Gulf bays; year-round in south Florida
Threadfin Herring
Opisthonema oglinum
The Gulf-side counterpart of the scaled sardine, the threadfin herring is a premier live bait for king mackerel, tarpon and speckled trout. The long last dorsal ray — the 'thread' — is its mark, and it is fragile: it dies fast in a crowded live well, so it must be handled gently and used promptly.
Seasons · Peak
Identifying features
- Long, thread-like last ray of the dorsal fin — the key mark
- Deep silvery body with a greenish back ('greenback')
- Faint dark shoulder spot behind the gill cover
- Small dark spots sometimes forming a row along the upper side
- Soft body and easily shed scales, more delicate than a sardine
Habits
- Forms huge schools in bays and just off beaches
- Feeds on plankton filtered while swimming
- Marked at the surface by diving birds and oily slicks
- Fragile — dies fast in a live well if crowded or poorly aerated
- A premier live and cut bait across the Gulf Coast
Distribution
Where to find them
- Louisiana bays and platforms off Grand Isle
- Texas bays and passes from Galveston to Corpus Christi
- Florida Panhandle bays and piers in summer
Where they live
How to catch them
Cast nets over bay schools Boat
Rig: 7-9 ft cast net thrown over schools marked by birds and slicks in bays and passes
Bait/lure: Cast net (no hook bait)
Key tip: Do not overcrowd the well — threadfins are fragile and die fast in a live well; use them promptly or keep numbers low with strong aeration.
Sabiki rigs around platforms and piers Shore
Rig: Light spinning rod with a tiny-hook sabiki rig jigged around Gulf platforms, piers and bridge shadow lines
Bait/lure: Sabiki rigs
Key tip: Jig gently in midwater and lift fish straight into the well; rough handling kills them.
Best baits & lures
Baseline setup
- Rod: Light 6-7 ft spinning rod
- Line: 4-8 lb mono
- Terminal: Cast net, tiny-hook sabiki rigs and a well-aerated live well
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 4-7 in (10-18 cm); large fish to about 10 in (25 cm)
On the table
Poor — soft and bony; valued as live and cut bait, not as a table fish.
Similar species
Scaled SardineScaled sardine has no dorsal thread and a bolder dark shoulder spot; threadfin herring is marked by its long thread-like last dorsal ray
Gizzard ShadGizzard shad is a mostly freshwater shad with a blunt snout and a dark shoulder blotch; threadfin herring is a saltwater bay fish with a longer dorsal thread and greener backRegulations 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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