|Clupeiformes display at the Smithsonian Natural History Museum.|
Clupeiformes are physostomes, which means that the gas bladder has a pneumatic duct connecting it to the gut. They typically lack a lateral line, but still have the eyes, fins and scales that are common to the fish family, although not all fish have these attributes. They are generally silvery fish with streamlined, spindle-shaped, bodies, and they are often schooling. Most species eat plankton, which they filter from the water with their gill rakers.
The order includes about 300 species in seven families:
- Family Chirocentridae (wolf herrings)
- Family Clupeidae (herrings, sardines, shads, and menhadens)
- Family Denticipitidae (denticle herring)
- Family Dussumieriidae (round herrings)
- Family Engraulidae (anchovies)
- Family Pristigasteridae
- Family Sundasalangidae (Sundaland noodlefishes)
Timeline of genera 
- Sepkoski, Jack (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology 364: p.560. Retrieved 2011-05-17.