Shonisaurus...?

[Kalandros]

Minimal Perception needed for HQ Mahar is 320 (if I remember correctly?)

Therefore, Shonisaurus requires 320 perception

I've caught 4 NQ Mahars with sub 320 perception :\

[Shinzoku]

I read somewhere that the requirements were 384/321 although those may not be the exact numbers. I used NQ Haddock dip for the perception boost, but I did have the fc gathering buff up (385 gathering with max melded gear and supra). You may want to wait to get the Ironworks rod to catch it if you don't have access to the fc buff.