Pond Boss Forums INTRO Questions & Observations Paddlefish... aka "Spoonbill"

Notochords are what non-vertabrate members of the (Order?) Chordata have instead of spines and spinal chords. (All vertabrates are chordates, but not all chordates are vertabrates.) It is supposed to be an oily fluid filled tube running about where you would expect to find the backbone.

Chordates predated the development of vertabrates. IIRC "fishes" are so ancient that they include both vertabrate and non-vertabrate chordates. Perhaps the best known member of the latter group are the coelacanths, the living fossils though to be extinct for 60-200 million years before having a live specimen caught off Madagascar identified about 1931. (There are multiple species of coelacanths still around and they are also find near Indonesia.) Based on your description, Blackjack, it sounds to me like the paddlefish is another non-vertabrate chordate.