Final answer:
Sevruga caviar is sourced from the smallest sturgeon species, Acipenser stellatus, and features small, grey eggs with an intense flavor.
Step-by-step explanation:
The caviar that comes from the smallest sturgeon with eggs that are also small and range light to dark gray is the Sevruga caviar. Sevruga sturgeons, scientifically named Acipenser stellatus, are the smallest species of sturgeon that produce caviar. Compared to its counterparts like the Beluga or Osetra, Sevruga caviar is noted for its smaller eggs and their distinct, more intensely flavored, firm grains that come in a variety of grey shades.