The reason many gars are taking pelleted feed directly from the store these days is because breeders particularly in Asia are now pellet feeding the young rather than using the more conventional method of live feed (Which is more common here in the US). This is because of the decades of work being put into the aquaculture of gar being implemented. Most Gars that hobbyists obtain are from three sources, Wild caught, or Aquacultured either here or in Asia. Majority are now farmed rather than wild caught.. So yeah there is a protocol to doing this and your benefiting from the end results of those doing this research on these fish to improve the culturing of them in captivity.
Your welcome....
For the record you can easily do a search here on MFK about Training gar to eat pellets. The whole process is well written out in a number of posts.
