Interactions
Silver Lamprey are only parasites during the adult part of life, which only lasts about one to two years (Docker et al. 2009). But this is the form that lamprey are most commonly associated with. Since Silver Lamprey are aquatic freshwater parasites they prey exclusively on fish. Silver Lamprey prefer hosts without scales or scales that are very small in size. For this reason their favorite hosts to attach are catfish, paddle fish, sturgeon, and lake trout (Cochran et al. 2003). But, Silver Lamprey are opportunist and will attach to many different species of fish. Studies have shown that when lamprey use invasive carp species with large thick scales as their host they experience very little growth (Cochran et al. 2003). This is thought to be caused by lamprey being unable to successfully bore through the carps scales and create a viable hole to acquire blood and other nutrients through.
Shown above are the mouth structures of different species of lamprey.
Silver lamprey have been found to attach more commonly to the
backs of fish who feed on the bottom of rivers. This lessens the chance of
the lamprey being disattached from its host by being scraped off by debris
on the bottom of rivers and bodies of water. Lamprey are found on
paddlefish and other fish who commonly inhabit the pelagic zone (Cochran et
al.
2009). The skin on the underbellies of paddlefish is softer and contains
high amounts of oil. For both of these reasons Silver Lamprey prefer to
attach to the underbellies of paddlefish. It is hypothesized that Silver
Lamprey may actually be able to use the oil itself as a nutrient source
(Cochran et al. 2009).
In the winter some Silver Lamprey remained attached to their
host while others live without host for extended amount of time and attach
to rocks and other objects near the bottom. The exact number of Silver
Lamprey who remain attached to host for winter months is unknown, because of
the many difficulties observing and tracking lamprey during the winter in
their natural habitat. It is thought that Silver Lamprey prefer a larger host
in the winter. Larger hosts allow for a greater amount of resources so the
lamprey doesn’t have to waste precious energy searching for a new host. It
also gives the lamprey more protection (Cochran et al. 2009).
The exact number of predators of Silver Lamprey is unknown.
Animals are rarely observed eating Silver Lamprey in the wild. Silver
Lampreys are also easily digested by many animals because they have very few
bones. The populations of Silver Lampreys are dispersed for most of the year too,
making sightings of predation harder to come by (Cochran et al. 2009). Walleye,
brown trout, and northern pike are all known fish species who prey on Silver
Lampreys. Northern pikes have been observed feeding on Silver Lampreys as they
make their yearly migrations.
Walleyes have been known to feed on ammocetes
who preside on muddy bottoms. Birds who are predators of Silver
Lampreys
include gulls and mergansers. Mergansers are one of the only species that
is known that uses Silver Lamprey has a main staple of their diet.
Raccoons, muskrats, rats, weasels, foxes, hawks, and owls are all thought
to be predators of Silver Lampreys, but have seldom, if at all, been seen
actually consume a Silver Lamprey (Cochran et al. 2009). Silver Lampreys aren’t known
to be a fish that humans enjoy eating, but more as a parasite that destroys
other fish we enjoy eating. Silver Lampreys are used by different fishermen
mainly in the ammocete stage as bait for some game fish. Fly fishermen also
also make flies that resemble Silver Lamprey ammocetes (Cochran et al. 2009).
To find additional information, check out the Facts page.