Prima Games is the largest strategy guide publisher in the United States. They have made a number of Pikmin-related guides, with in-depth walkthroughs. On top of that, they also commonly include extra information about subjects in the series that isn't given anywhere else, like the scientific names of enemies in Pikmin. Since it is impossible to know if this extra information is endorsed by Nintendo, or made up by Prima Games writers in order to richen the guide, it is left as ambiguously canon. Some incorrect and dubious information also contributes to it being ambiguously canon, as explained here.