Friday mystery object #184 answer (well, not really)

On Friday I asked for your help with identifying this object:


There were a few interesting suggestions from beaks to bladders, but so far nothing really corresponds with the structure of this specimen. It’s very weird.

It looks like it’s probably from something aquatic, perhaps the ossified swim bladder of a fish, but I’m by no means sure of that.

I will see if I can read the notes written on the specimen under a UV light, but for now I have to admit that I am still stumped. Please let me know if you recognise what it is!

[N.B. from the discussion and links in the comments below, it emerges that this is the hyperostotic spine from the anal fin of a fish]

17 thoughts on “Friday mystery object #184 answer (well, not really)

  1. Sorry, I’ve only just seen this one. I have a suggestion…not sure if someone has made this suggestion already, I haven’t seen the original post. Have you considered hyperostoses? Apparently they are common in tropical and subtropical fish. I have a schnapper skeleton that has small ones (its only a 60cm fish). I was going to attach the picture but I don’t think I can…

  2. Here’s another pic.
    They call it a tilly bone which is apparently another name for a hyperostosis. The skeleton I have has them on the haemal spine, but the xray on the page that henstidgesj attached also shows them on the neural spines. They are apparently common in the skulls of Schnapper, but don’t quote me on that.

    • The mystery object #184 is the hyperostotic spine of a fish. Ones found in our area (Gulf of Mexico) have been attributed to the dorsal spine of a large black drum (Pogonias cromis) though other fish can have such spines. The pointed objects on the end are the pterygiophores.

  3. Okay, I don’t just have a bone that looks similar to this, I have one that is identical, down to the grooves in the pod part. Your picture is the first I’ve found in five years of searching!!!!

  4. Yeah it is a swollen bone (or hyperostosis) from teleostean fishes. Differents bones of the skeleton can grow like this. Nevertheless, these bones are “specie diagnostic”, and this one is an anal fin pterygiophore. For the specie attribution, see also Platax cf. teira (family Ephippidae) – depending of the region of discovery.

  5. I realized this was 9 years ago but this was found in the Chesapeake bay United states 2 days ago. Did you ever figure out what the mystery object was

    • We figured out that it’s the hyperostotic spine from the anal fin of a fish, but due to the deformation it’s very difficult to pin it on a particular species.

      Kevin L. suggested that it’s from a fish in the family Ephippidae.

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