The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Ctenopharyngodon idella × Hypophthalmichthys nobilis
Ctenopharyngodon idella × Hypophthalmichthys nobilis
(Grass Carp × Bighead Carp)
Exotic Hybrid

Copyright Info
Ctenopharyngodon idella × Hypophthalmichthys nobilis

Common name: Grass Carp × Bighead Carp

Identification: Similar to pure grass carp but with many features intermediate between the two parent species. Howells (1992) provided distinguishing features. Maximum size: Probably similar to grass carp, 75 -125 cm.

Native Range: None; artificial hybrid.

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Ctenopharyngodon idella × Hypophthalmichthys nobilis are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
AZ197019701Lower Salt
CA197919792Lower Colorado; Salton Sea
TX198319901West Fork San Jacinto

Table last updated 6/18/2024

† Populations may not be currently present.

Means of Introduction: Intentionally stocked by the Texas Parks and Wildlife Department in 1989 (Howells 1992a).

Status: Reported in Arizona and Texas. Eradicated in California.

Impact of Introduction: It failed to control hydrilla in the Salton Sea.

Remarks: This hybrid is believed, but not proven, to be sterile. As of 1990 it is illegal to possess this hybrid in Texas (Howells 1992a).

Other Resources:
Fact Sheet for Ctenopharyngodon idella - USGS Nonindigenous Aquatic Species Database

Fact Sheet for Hypophthalmichthys nobilis - USGS Nonindigenous Aquatic Species Database

Author: Fuller, P.

Revision Date: 5/9/2019

Peer Review Date: 4/11/2006

Citation Information:
Fuller, P., 2024, Ctenopharyngodon idella × Hypophthalmichthys nobilis: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=515, Revision Date: 5/9/2019, Peer Review Date: 4/11/2006, Access Date: 6/18/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [6/18/2024].

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