It is a Cypriform and what is termed a "filter feeder". That means it mainly eats minute organisms such as zooplankton and detritus; also algae.
We had several filter feeders in South Africa, notably the Orange River Mudfish - Labeo capensis and the Mud Mullet or Moggel Labeo umbratus.
The mudfish was easily caught on small pieces of bread paste, flake or flour dough mixed with egg. The moggel had the reputation of being impossible to catch on rod and line. However, myself and a few other anglers developed artificial flies that were quite effective. These fish went up to about 7lbs maximum.
One thing common to filter feeders is that they fight very hard indeed. Much harder than say a barbel. The battles I have had with 5lb mudfish you would not believe.
I, dont think these Big Head carp would be too popular with English carp anglers. I doubt if boilies and bolt rigs would work. Fly fishing and jig fishing - yes, but these methods require a modicum of skill.