1 Pain: Persistent mouth pain is another common oral cancer sign. 2  A lump or thickening in the cheek. 3  A white or red patch on the gums, tongue, tonsil, or lining of the mouth. 4  A sore throat or feeling that something is caught in the throat that does not go away.
Blue whales are the largest predator to ever inhabit this planet, though it is thought to feed almost exclusively on tiny, shrimp-like creatures called euphausiids or krill. Feeding is usually at depths less than 100 m; harpooned animals have dived as deep as 500 m.lue whales, Balaenoptera musculus (Linnaeus, 1758), like all rorquals (Family Balaenopteridae, the family that includes the blue whale, Bryde's whale, fin whale, humpback whale, minke whale, and sei whale), are long, slender whales that are much more streamlined than other large whales.
As far as other predators are concerned humans still remain the primary threat to blue whales. Most countries have adopted rules that ban whale hunting, however there are also several countries that still endorse this type of activity.hile these instances are rare there have been people who have confirmed witnessing such attacks and even a few videos have been recorded showing a group of killer whales attacking a blue whale.