My first thought is that it looks like a Dendrobium but I could be completely off. Do you have a reason for thinking catasetum or is that just a guess?
I understand the suggestion of Dendrobium, but I also see a resemblance to Cyrtopodium or Galeandra or even Clowesia or Cycnoches. The photo isn't very clear. What is the texture of the leaves? Does it look like lower leaves have been lost, or is this all the leaves it ever had?
hi there it appears the new shoot has leaves around the sheath the texture of the leaves is bristle and the leaves are quite purple here is a few more photos thanks for your help!