Alosa pseudoharengus (Alewife)
Animal
Type: Fish
Family: Clupeidae
Classification: Regulated
www.forestryimages.org |
http://www.anr.state.vt.us/dec/waterq/ans/alewife.htm |
The
Alewife, also called grey herring or golden shad, is a small herring. They
are an
anadromous species, although there are some landlocked populations around
the Great Lakes. When anadromous, the fish can reach 12 - 15 inches
in size, and females lay from 60,000 to 100,000 eggs. When landlocked the
fish tend to grow only to about 6 inches, and the females will lay 10,000
to 12,000 eggs. When landlocked they will feed on the eggs and young of other
fish, as well as their own. They also selectively feed on the larger species
of zooplankton. They are a forage fish for larger species. However eating
them has been found to cause reproductive failure in landlocked salmon and
trout species. Alewives contain enzymes that diminish the ability to store
thiamin in tissues. The thiamin deficiency causes an illness called Cayuga
Syndrome, which can cause 100 % mortality in larval offspring of landlocked
salmon and trout.
Alewife are
not considered game fish or a food fish, although they are sometimes harvested
for pet food or used for chumming. When landlocked they sometimes experience
massive die-offs. Possibly related to the water getting warmer. If anadromous
populations were to become established they could interfere with native shad,
smelt, and herring populations.
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