Friday, March 17, 2017

Shad and Herring

Spring is coming, and so are the shad and herring runs, so let's all bone up on ID so we know what we're catching, shall we? In CT targeting and keeping anadromous alewives and blueback herring is illegal so being able to distinguish these from shad is important, and it is possible to run into another less commonly caught shad species, the gizzard shad. And if you are good and fish the right spots at the right times, you could get lucky and catch the full Fly Shad Slam: hickory, american, and gizzard. Getting that last one is TRICKY!

The two species of river herring are very difficult to distinguish physiologically without cutting one open, and since you can't legally kill one without specific permission from the DEEP and the vast majority of fisherman do not have the time or skill to learn how to identify between alewives and bluebacks, I'm not going to got into that... instead I will clarify the distinctions between the other shads and herring that could be encountered in the same water.

Alewife, Alosa pseudoharengus, found dead, probably from energy loss during spawning. Still milting. 

Blueback herring, Alosa aestivalis caught while counting for DEEP
The first important thing to distinguish a river herring from is an Atlantic herring, as they are the same size and have similar mouths and coloration. Atlantic herring can be kept. River herring cannot. The key to identification is the presence or absence of belly scutes. Sea living herring have no scutes, but you cannot easily tell the difference by looking. Put you sleeve or any part of your shirt over your finger and rub it from tail to nose on the fish's belly. If it is a river herring, the fabric will catch on the scutes, whereas a sea herring will be smooth.
Any herring caught in fresh water will be a river herring anyway, if it is smaller than a shad (15 inches is a good rule of thumb for max river herring length). To be certain look at the fish's lower jaw. Pull the lower jaw open and look at the slope of it as it enters the mouth. If it is sharply rising, it’s an alewife or a blueback herring. If it's a gradual rise, it’s a shad.  If the water is slightly brackish the fish could be an Atlantic menhaden, which can be identified by looking at the scales running along its back. If they form an overlapping pattern like a zipper it is a menhaden. 

When it comes to river herring the best policy is simple: if you don;t know let it go. I advocate catch and release fishing regardless, but I know some anglers will want to keep some herring or shad and I strongly encourage those anglers to be absolutely positive in their identification of shad and herring, as river herring are a very valuable species and need as much help as they can get. And that's ignoring the penalties illegally taking herring bring upon a negligent angler. 

Hickory shad, Alosa mediocris

Now shad... there really is no real penalty for not knowing what kind of shad you are catching, whether it be hickory, American, or gizzard.  That being said, it is good to know what you are catching. Ignorance may be bliss to some but knowledge is a great tool, I personally like knowing exactly what kind of fish I'm catching as a biologist and multi species angler.
American shad, Alosa sapidissima, caught on a two hander by Sonny Yu (photo courtesy Sonny Yu)

American shad are the largest of the three. They commonly top 20 inches. Hickory shad are noticeably smaller and average 15 inches. The two most noticeable distinguishing characteristics are the jaw length and gill rakers. A hickories' lower jaw extends well past its upper jaw when fully closed, while the American's upper and lower jaw are matched. The gill rakers of a hickory typically number in the 60's and look like a feather or brush. An American shad's gill rakers are more separated, like a comb, and typically number from 18-22. 

Gizzard shad are the most clearly different of all the species I've discussed so far. Instead of a thin, papery, almost crappie like mouth they have a short blunt snout and a very small mouth, almost but not quite bluegill like. The rear spine of the dorsal fin trails back beyond any of the others as a filament. They don't get as large as American shad but may grow as large as 20 inches. 

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Mike Andrews with a large fly caught gizzard shad, Dorosoma cepedianum. (Photo courtesy Michael Andrews)

This is not the full picture, for more on shad and herring identification do some reading:

And for some good information on fly fishing for shad check out Sonny's blog and book, he knows his stuff!


  1. WOW, great info! As you said, "catch and release" is always a good idea. The Irish always release the catch.
    Tie, fish, write and photo on...

    1. There are times when keeping fish is not only a good idea but legally required. Wherever brook trout are found out West I suggest fisherman keep as many as they can to protect native cutthroat. And I'm pretty sure a lot of those Irish salmon and trout anglers are keeping fish! But yes, catch and release works well in most cases.

  2. Thanks for the education! Very interesting info!

    1. It's my pleasure. I enjoy talking fish more so than fishing sometimes!