parasitic helminths (trematodes) of marine fishes under a microscope.

ache anisakiasis ascariasis background biology cestoda cyst danger digenean disease diseases fish fishes flatworm fluke food fresh healthy helminth helminths host infection intermediate intestinal intestine larva meat medical medicine microscope microscopic nematode opisthorchiidae parasite parasites parasitic parasitology platyhelminthes raw roundworm roundworms science scientific stomach tapeworm tissue trematoda trematode worm zoology