Origin
The Hypophthalmichthys molitrix or Silver carp are native to Asia. Silver carp is a large fish that can reach more than 4 ft. (1.2 m) and 70 lbs. (31.8 kg). It has a compressed (relatively flat side to side) body form. Its back is olive in color, fading to bright, silvery sides and a whitish belly. Its ventral surface also features a prominent, sharp keel from throat to anal fin. The head is scaleless with a large terminal mouth. Its eyes are set forward and downturned, below the body’s midline.

Life Cycle
H. molitrix require bodies of water with some current for eggs to float and develop properly. Carp carry out migrations to communal spawning grounds during spring flooding. They prefer to spawn in small groups of 15 to 25. They typically reach reproductive maturity from 3 to 10 years old. Females can produce from about 300 to over 5000 eggs.

Distribution
H. molitrix have been introduced around the world. They have been found in Africa, Australasia-Pacific, North America, and South America. They were introduced accidently to the Mississippi River system in 1990 due to flooding and now have been recorded in 12 states.

Control Efforts
H. molitrix feed by filtering phytoplankton from the water using specialized gill structures. This reduces the amount of food available to native aquatic animal species. H. molitrix have also been found to carry and transmit the disease Salmonella typhimurium. Cooperation between the states where the species has spread to ensure consistency in regulation and enforcement is recommended for more effective control.

Resources

• Nonindigenous Aquatic Species Database - U.S. Geological Survey
• Fact Sheet - Ontarios Invading Species Awareness Program

Selected Images

Maps

Invasive Listing Sources

• Alberta Fisheries Act
• Florida Conditional and Prohibited Non-Native Species Lists
• Florida Conditional and Prohibited Non-Native Species Lists
• Idaho Invasive Species Act
• Maryland Aquatic Nuisance Species Plan
• Maryland Invasive Species Council - Invasive Species of Concern in Maryland
• Michigan’s Invasive Species Watch List
• Michigan’s Prohibited and Restricted Species
• Minnesota DNR invasive species list
• New Jersey Invasive Species Strike Team 2017 Invasive Species List
• New York Regulated and Prohibited Invasive Species - Prohibited
• Ontario’s Invading Species Awareness Program Tracked Species List
• Pennsylvania's Field Guide to Aquatic Invasive Species
• West Virginia Invasive Species Strategic Plan and Volunteer Guidelines 2014
• Wisconsin's Invasive species rule – NR 40

References