12 Days of FISHMAS! Day Four!

Day four of the Twelve Days of Fishmas! Day three can be found here. The tag for the whole set will be here.

On the fourth day of Fishmas cladistics gave to me…

  • Four elopomorphs born from leptocephali
  • Three Holosteans
  • Two Chondrostei
  • And a bichir at the base of Actinopterygii

On day four, we reach the Elopomorpha, as a group of fish related by having a leptocephalus stage. It’s a fairly diverse group of fish, including eels, pelican eels, tarpon, bonefish and notacanthiforme spiny eels. It’s pretty crazy that this wide range of animals are all so closely related–such is the morphological diversity of fish! As a group, the elopomorphs form the sister to the rest of the Telesotei (which contains most of the living ray-fin fish). Interestingly, it was only with recent studies that it was determined that elopomorphs were phylogenetically more ‘primitive’ than the bony tongues (hint!); I don’t fully understand enough to know the full reasons, but it seems to be bearing out with further molecular and morphological study.

Although a fairly diverse clade of fish, there’s a bit of a limit to the figures that represent them. Most obviously, so many eels! For today’s post, we have the Kaiyodo Capsule Aquarium Dragon Moray eel, the Kaiyodo Capsule Aquarium Spotted Garden eel and the Yujin Primary Seawater Fish series Japanese Conger eel. Overall, the eels as a whole are probably the first group of fish in these clades with a variety that could be thought of as ridiculous…I was very spoiled for choice and still messed up. I meant to include a pelican eel of some kind as well, but didn’t (but there are several!) Thanks to Toy Fish Factory, I can at least have an Atlantic Tarpon to represent more taxonomic diversity. Maybe some day we’ll get a marine spiny eel (not to be confused with the freshwater mastacembelid spiny eels) or a bonefish. Something to shake things up a little.

Up next…something gold?

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