Atlantic Thread HerringorScaled Sardine
Two fish anglers mix up. Here is what separates them, and what each one’s rules are in your state.
How to tell them apart
Atlantic Thread Herring
Last dorsal ray trails into a long thread; single shoulder spot on a deep herring body.
Atlantic thread herring, next to scaled sardine: trailing dorsal thread.
Scaled Sardine
Bright bait sardine with a faint shoulder spot and no trailing threads; the castnet standard.
Scaled sardine, next to Atlantic thread herring: no thread, slimmer.
Side by side
| Atlantic Thread Herring | Scaled Sardine | |
|---|---|---|
| Scientific name | Opisthonema oglinum | Harengula jaguana |
| Also called | Threadfin, Greenie | Whitebait, Pilchard |
| Waters | Inshore | Inshore |
| Heaviest state record | — | — |
| On the table | Bait. | The livewell staple — bait. |
| Rules of its own in | 2 states | 2 states |
Rules for
Every state, both fish
The two fish are regulated differently in 2 of 2 states with a rule for either. In Florida (Atlantic), Atlantic thread herring is No size limit, 2 fish or 100 lb per person per day (whichever is more) and scaled sardine is No size limit, No bag limit for bait. Call the fish wrong and you keep a short one or throw back a legal one.
| State | Atlantic Thread Herring: size · bag · season | Scaled Sardine: size · bag · season |
|---|---|---|
| Florida (Atlantic) | No size limit2 fish or 100 lb per person per day (whichever is more)Open year-roundOpenFWC 2026 · checked | No size limitNo bag limit for baitOpen year-roundOpenFWC 2026 · likely · checked |
| Florida (Gulf) | No size limit2 fish or 100 lb per person per day (whichever is more)Open year-roundOpenFWC 2026 · checked | No size limitNo bag limit for baitOpen year-roundOpenFWC 2026 · likely · checked |
In the app
Point the camera at the fish and Chum names it before you take the picture, Atlantic thread herring or scaled sardine, with the right rules for the water you’re standing in. No signal needed.
Get the appQuestions anglers ask
How do you tell Atlantic thread herring from scaled sardine?
Atlantic Thread Herring: Last dorsal ray trails into a long thread; single shoulder spot on a deep herring body. Scaled Sardine: Bright bait sardine with a faint shoulder spot and no trailing threads; the castnet standard. Scaled sardine, next to Atlantic thread herring: no thread, slimmer. Atlantic thread herring, next to scaled sardine: trailing dorsal thread.
Which is better to eat, Atlantic thread herring or scaled sardine?
Atlantic Thread Herring: Bait. Scaled Sardine: The livewell staple — bait.
Do Atlantic thread herring and scaled sardine have the same limits?
Not everywhere. They differ in 2 state rulebooks. Florida (Atlantic): Atlantic thread herring No size limit, 2 fish or 100 lb per person per day (whichever is more), scaled sardine No size limit, No bag limit for bait; Florida (Gulf): Atlantic thread herring No size limit, 2 fish or 100 lb per person per day (whichever is more), scaled sardine No size limit, No bag limit for bait.