Thats a good question. My assumption is that there probably isn't a size limit on Smallmouth, Spotted or Meanmouth bass on Cedar Creek, unless a general state-wide regulation comes into play. Cedar isn't supposed to have those species and the 20" size limit would only apply to Largemouth. I'll see what I can read up on that. *After re-reading your question I feel like you meant on any body of water. My guess is, is that since it isn't a smallmouth, spot or LM that it would probably not have a specific length requirement. I've yet to see KDFWR recognize a MeanMouth as even existing on paper anywhere. They will acknowledge it as far as talking about them and admitting they exist etc. But they have yet to publish any regs on them.