Nothing fishy about it

 

 

In mammals the antibodies in the immune system produced by B cells help fight infection. However in fish, scientists have discovered that B cells undergo a process known as phagocytosis, in which B cells ingest foreign particles and microbes. The round cell in the lower left, is B cell from a trout. It is in the process of devouring three latex beads, each (arrow) about 1 micron in diameter.