 
                         
                         
                     /
                                            /
                                             
                                                                            
                                 Adaptability
                                                                                    
                                                                                                                    
                                            Adaptability
                                                                                         
                                                                                    
                                                                                                             Rattled
                                        The Pokémon gets scared when hit by a Dark-, Ghost-, or Bug-type attack or if intimidated, which boosts its Speed stat.
                                        Rattled
                                        The Pokémon gets scared when hit by a Dark-, Ghost-, or Bug-type attack or if intimidated, which boosts its Speed stat.
                                 Adaptability
                                        Powers up moves of the same type as the Pokémon.
                                        Adaptability
                                        Powers up moves of the same type as the Pokémon.
                                They live in frigid seas, forming schools and sharing food among themselves. When the time comes, they return to the river they were born in.
Its ecology is starkly different from that of other Basculin, so theories that it's a totally different species have gained traction in recent years.
Though it differs from other Basculin in several respects, including demeanor—this one is gentle—I have categorized it as a regional form given the vast array of shared qualities.