BIO 203


     The Silver Lamprey can parasitize many kinds of fish with the most common being paddlefish, muskellunge, or any other type of fish with small scales or scaleless skin altogether (Robison et al 2011; Cochran 2010).  They predate upon these species with small scales or scaleless skin because they are more vulnerable in that they lack the advantageous armor of large, hard scales that other fish possess. The soft skin allows for the Silver Lamprey to latch on and hold tight (Cochran & Lyons 2010).  

Paddlefish Drawing. Credit: Timothy Knepp

Shown above is a Paddlefish, the Silver Lamprey's common food source.

     Lampreys are usually nocturnal, and use olfaction (sense of smell) or electroreception to find the host species (Cochran & Lyons 2010). Electroreception is a sensory characteristic found in some fish that allows them to detect electric fields via special sensory organs (Merriam Webster 2014).  Lampreys can be found on any part of the host species with attacks occurring more often on the ventral portions of the host (Cochran & Lyons 2010).  This may be due to a higher abundance of lipids on this surface of the host which may attract more lampreys (Cochran & Lyons 2010).  They have also been found quite commonly inside the branchial cavity of paddlefish (Robison et al 2011; Cochran & Lyons 2010).  One individual paddlefish was recorded to have as many 10 to 25 of the parasitic lamprey on them in the portion of the Mississippi River known as Lake Pepin (Cochran & Lyons 2010). Once attached to a host species, the Silver Lamprey punches a hole through the skin and commences feeding on the blood and muscle tissue of the host (Cochran & Lyons 2010).  Often, the Silver Lamprey target the dorsal or ventral aorta of the host because these large blood vessels provide a high amount of nutrition (Cochran & Lyons 2010).  Some speculate that with access to blood at such high pressures, the Silver Lamprey would have the ability to fill its gut with blood in a relatively passive manner (Cochran & Lyons 2010).  If it attached anywhere else on the body that lacked blood at high pressures, the Silver Lamprey would be forced to exert more energy in order to obtain its nutrients (Cochran & Lyons 2010).

To find additional information, check out the Reproduction page.