Skip to main content

How to Tell Whitebait and Threadfin Apart

It's the time of year for sardines and herrings to invade Florida bays and rivers.

How to Tell Whitebait and Threadfin Apart

Top to bottom: Threadfin herring (greenie), scaled sardine (whitebait) and Spanish sardine

In the springtime, scaled sardines (a.k.a. “whitebait” or “pilchard”) and threadfin herring (a.k.a. “greenback” or “greenie”) rank at the top of the list of Florida live baits.

The threadfin herring has a vibrant green back and prominent spots along the dorsal ridge. Most telling is the long, thread-like trailer extending from the anterior portion of the primary dorsal fin. The sardine lacks the dorsal trailer, has a noticeably larger eye, a light olive green back and scattered spots. (Spanish sardines sometimes mix with these— they'll be recognizable by their lack of back spots, and, as adults, their long, thin profile.)

Is it possible to tell them apart from afar?

Tampa Bay area guide Billy Miller says, “When you see bait on the flats running and making a commotion, those are the greenbacks. Whitebait will usually hang in one area. When you see bait ‘raining' on the surface, those are your greenbacks. Whitebait will just dimple the surface; you'll see one roll here, one there."

fisherman throwing cast net toward bridge pilings
Bridge pilings tend to hold bait and are a good place to check.

Scaled sardines typically remain inside bays and estuaries longer than threadfins of similar age. That means you'll often find the big whitebait on deeper flats, while locating sizable greenies requires a trip to the pass, beach or markers.

Bridges, like the Sunshine Skyway, see both bait species holding near the pilings. You'll see flashes in the water column and plenty of surface activity—particularly when mackerel or jacks find a school. Just remember the high-low thing.

“Scaled sardines typically hug the bottom and threadfins are typically toward the surface,” said St. Pete's Capt. Rob Gorta. “If you're in 20 feet and the bottom machine reads 15 feet, you know there's five feet of scaled sardines on the bottom. Threadfins will be suspended five to 10 feet below the surface.”

How to Catch Whitebait & Threadfin

fisherman pulls castnet out of the water full of live bait
It's a full house.

Over broad flats or on beach fronts, where bait schools often hug the shoreline contour, just idle until you spot a thick dark mass and sling the mesh “rodeo” style. For a more concentrated effort, set up on the edge of a grass flat and chum with moistened fish meal or tropical fish feed.

An old-school classic: Canned jack mackerel hand-mashed with wheat bread and just enough sea water to form a smelly paste. Flick fingernail-sized chunks downtide and once baitfish rise to gobble the chum, “walk” them into cast net range with progressively closer chumming.




Miller makes a key point: “Threadfins will not chum. If you see baitfish responding to your chumslick, that's whitebait. Once the whitebait gets excited, the threadfins will sometimes follow them.”

For cast netting livies, Capt. Jason Stock of Bradenton recommends a 1/4-inch stretched mesh (measured corner to corner of a net square when diagonally stretched) for shallow flats, 3/8 around deep bridge sections and 1/2-inch for larger baits, deeper coastal waters and stronger current. Remember, the wider the mesh, the faster the net sinks.

threadfin bait on a plain white surface with a pair of scissors below it
Some threadfins not looking so lively? Tarpon and sharks will go for a fresh-cut threadfin soaked on the bottom.

Cast nets are most time-effective, but sabiki rigs, or any homemade gold-hook rig will tempt whitebait and greenies. This can be a good option when you're limited by wind, tide or cast net experience.

Recommended


Dollar bill-sized threadfins make dandy offerings for tarpon, monster snook, sailfish and even offshore bullies like amberjack and grouper. Also, Gorta favors big threadfins for redfish cut bait because they release so much aroma that reds can track ‘em down even in dim conditions and murky water. Coastal sharks also dig cut greenies and don't think the mighty silver king won't stoop to scooping up a freshly cut half.

Whitebaits are the go-to choice for live baiting snook of common proportions, along with redfish, trout, cobia, small sharks and even tripletail. Baits of 2 to 4 inches fit the bill; smaller for tripletail, larger for sharks.

fisherman holds nose hooked sardine in front of a rod and reel
Nostril hooking works well for fishing in current.

Hook either baits through the cartilage between the eyes and nostrils for fishing in current. In calm water, hide the hook beneath your bait by running it through the soft pocket right behind the pectoral fin joints. (This works equally well for free lining or floating baits under corks.)

If you've collected mostly greenies, it's inevitable a good number of them will expire in captivity. Skim dead ones out of the well and hold them on ice for snapper bait, or grind them with the day's leftovers into homemade chum blocks. FS

First Published Florida Sportsman Magazine April 2017

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Recommended Articles

Recent Videos

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Videos

Kayak Fishing Fun 2023 Product Showcase

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Store

Refurbished 1987 Alumacraft Jon Boat | One Man's Dreamboat

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Learn

New Berkley Finisher: The All-Around Live Sonar Lure

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Gear

New Berkley Power Switch: Powerhouse Lure Designed for Foward-Facing Sonar

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Gear

New Berkley Krej: A Reversed Lip Jerkbait?

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Store

How to Install New Fuel Tanks in an Old Boat

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Videos

Testing Out the Latest from Old Town in the Marquesas

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Store

How to Powder Coat: Benefits of Powder Coating Metal Fuel Tanks

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Gear

Father & Son Customize a 20' Center Console | One Man's Dreamboat

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Gear

Best Features of the Shallow Sport X3

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Learn

How to Fix an Outboard Motor that was Submerged in Saltwater

The crew at Marine Customs Unlimited takes on restoring a 31' Contender that has seen Better Dayz.
Store

Analyzing a Hurricane Damaged Boat for Restoration

Florida Sportsman Magazine Covers Print and Tablet Versions

GET THE MAGAZINE Subscribe & Save

Digital Now Included!

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

Preview This Month's Issue

Buy Digital Single Issues

Magazine App Logo

Don't miss an issue.
Buy single digital issue for your phone or tablet.

Buy Single Digital Issue on the Florida Sportsman App

Other Magazines

See All Other Magazines

Special Interest Magazines

See All Special Interest Magazines

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Get the top Florida Sportsman stories delivered right to your inbox.

Phone Icon

Get Digital Access.

All Florida Sportsman subscribers now have digital access to their magazine content. This means you have the option to read your magazine on most popular phones and tablets.

To get started, click the link below to visit mymagnow.com and learn how to access your digital magazine.

Get Digital Access

Not a Subscriber?
Subscribe Now

Enjoying What You're Reading?

Get a Full Year
of Guns & Ammo
& Digital Access.

Offer only for new subscribers.

Subscribe Now