Keep in mind the Tapajos variant does not seem as mellow as your 'typical' regani. Cr. regani is one of the mildest pikes out there (adult pairs have been kept in 20 gallon long/75 liter tanks) though I wouldn't try that with the Tapajos.
Oddly, I haven't seen the classic regani in years now, probably due to Brazil's newer export laws.
Oddly, I haven't seen the classic regani in years now, probably due to Brazil's newer export laws.