Introgressive hybridization between bighead carp and silver carp in the Mississippi and Illinois rivers

James Thomas Lamer, Chad Ryan Dolan, Jessica Lynn Petersen, John Howard Chick, John Michael Epifanio

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Asian carps are classified as either bighead carp Hypophthalmichthys nobilis or silver carp H. molitrix by multiple presumptively diagnostic morphological characteristics; however, hybrids pose a dilemma. Fish sharing the morphological characteristics of both species were observed in an Illinois River backwater (Calhoun County, Illinois) approximately 5 mi (8 km) upriver from the confluence with the Mississippi River as well as in two locations in Pool 26 of the Mississippi River (Madison County, Illinois). Biopsied tissues from individuals exhibiting mixed morphological features were analyzed at four diagnostic allozyme loci (ADH-1*, sMDH-A*, CK-A*, and sSOD-1*) via starch gel electrophoresis. This comparison revealed a high percentage of hybridization (22.5%) from an indiscriminate sample of 120 fish. Moreover, an unexpected percentage (12.5%) of individuals identified in the wild as either parental bighead carp or silver carp by gill raker morphology were genetically identified as hybrids. Finally, two levels of hybridization were detected, first-generation hybrids (F1) and post-F1 hybrids, revealing the onset of extensive introgression and the potential for a hybrid swarm. Variation in the amplified COII domain of mitochondrial DNA indicated a strong directional bias of hybrids (88%) containing silver carp maternal lineages. Morphologically, F1 hybrids were often identifiable (88%) by the presence of twisted gill rakers, but post-F1 hybrids were difficult to identify with any appreciable certainty. This result creates concern where taxonomic assignment is critical for management or monitoring, warranting a more extensive and intensive examination of this phenomenon in North American waters. Finally, prior observations in aquaculture have shown reduced jumping behavior, fitness, and condition of fish resulting from post-F1 matings between these species. This is the first confirmed presence of wild post-F1 individuals of Asian carps in the United States and, although further monitoring is needed, a hybrid swarm may ultimately decrease invasion success as introgression continues.

Original languageEnglish (US)
Pages (from-to)1452-1461
Number of pages10
JournalNorth American Journal of Fisheries Management
Volume30
Issue number6
DOIs
StatePublished - Dec 1 2010

Fingerprint

Illinois River
Hypophthalmichthys nobilis
Hypophthalmichthys molitrix
Mississippi River
introgression
silver
river
swarms
carp
gills
hybridization
fish
maternal lineage
colonizing ability
backwater
jumping
monitoring
starch gels
confluence
allozyme

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Aquatic Science
  • Ecology
  • Management, Monitoring, Policy and Law

Cite this

Introgressive hybridization between bighead carp and silver carp in the Mississippi and Illinois rivers. / Lamer, James Thomas; Dolan, Chad Ryan; Petersen, Jessica Lynn; Chick, John Howard; Epifanio, John Michael.

In: North American Journal of Fisheries Management, Vol. 30, No. 6, 01.12.2010, p. 1452-1461.

Research output: Contribution to journalArticle

Lamer, James Thomas ; Dolan, Chad Ryan ; Petersen, Jessica Lynn ; Chick, John Howard ; Epifanio, John Michael. / Introgressive hybridization between bighead carp and silver carp in the Mississippi and Illinois rivers. In: North American Journal of Fisheries Management. 2010 ; Vol. 30, No. 6. pp. 1452-1461.
@article{a7db178e771a471bbc253f537afca78f,
title = "Introgressive hybridization between bighead carp and silver carp in the Mississippi and Illinois rivers",
abstract = "Asian carps are classified as either bighead carp Hypophthalmichthys nobilis or silver carp H. molitrix by multiple presumptively diagnostic morphological characteristics; however, hybrids pose a dilemma. Fish sharing the morphological characteristics of both species were observed in an Illinois River backwater (Calhoun County, Illinois) approximately 5 mi (8 km) upriver from the confluence with the Mississippi River as well as in two locations in Pool 26 of the Mississippi River (Madison County, Illinois). Biopsied tissues from individuals exhibiting mixed morphological features were analyzed at four diagnostic allozyme loci (ADH-1*, sMDH-A*, CK-A*, and sSOD-1*) via starch gel electrophoresis. This comparison revealed a high percentage of hybridization (22.5{\%}) from an indiscriminate sample of 120 fish. Moreover, an unexpected percentage (12.5{\%}) of individuals identified in the wild as either parental bighead carp or silver carp by gill raker morphology were genetically identified as hybrids. Finally, two levels of hybridization were detected, first-generation hybrids (F1) and post-F1 hybrids, revealing the onset of extensive introgression and the potential for a hybrid swarm. Variation in the amplified COII domain of mitochondrial DNA indicated a strong directional bias of hybrids (88{\%}) containing silver carp maternal lineages. Morphologically, F1 hybrids were often identifiable (88{\%}) by the presence of twisted gill rakers, but post-F1 hybrids were difficult to identify with any appreciable certainty. This result creates concern where taxonomic assignment is critical for management or monitoring, warranting a more extensive and intensive examination of this phenomenon in North American waters. Finally, prior observations in aquaculture have shown reduced jumping behavior, fitness, and condition of fish resulting from post-F1 matings between these species. This is the first confirmed presence of wild post-F1 individuals of Asian carps in the United States and, although further monitoring is needed, a hybrid swarm may ultimately decrease invasion success as introgression continues.",
author = "Lamer, {James Thomas} and Dolan, {Chad Ryan} and Petersen, {Jessica Lynn} and Chick, {John Howard} and Epifanio, {John Michael}",
year = "2010",
month = "12",
day = "1",
doi = "10.1577/M10-053.1",
language = "English (US)",
volume = "30",
pages = "1452--1461",
journal = "North American Journal of Fisheries Management",
issn = "0275-5947",
publisher = "American Fisheries Society",
number = "6",

}

TY - JOUR

T1 - Introgressive hybridization between bighead carp and silver carp in the Mississippi and Illinois rivers

AU - Lamer, James Thomas

AU - Dolan, Chad Ryan

AU - Petersen, Jessica Lynn

AU - Chick, John Howard

AU - Epifanio, John Michael

PY - 2010/12/1

Y1 - 2010/12/1

N2 - Asian carps are classified as either bighead carp Hypophthalmichthys nobilis or silver carp H. molitrix by multiple presumptively diagnostic morphological characteristics; however, hybrids pose a dilemma. Fish sharing the morphological characteristics of both species were observed in an Illinois River backwater (Calhoun County, Illinois) approximately 5 mi (8 km) upriver from the confluence with the Mississippi River as well as in two locations in Pool 26 of the Mississippi River (Madison County, Illinois). Biopsied tissues from individuals exhibiting mixed morphological features were analyzed at four diagnostic allozyme loci (ADH-1*, sMDH-A*, CK-A*, and sSOD-1*) via starch gel electrophoresis. This comparison revealed a high percentage of hybridization (22.5%) from an indiscriminate sample of 120 fish. Moreover, an unexpected percentage (12.5%) of individuals identified in the wild as either parental bighead carp or silver carp by gill raker morphology were genetically identified as hybrids. Finally, two levels of hybridization were detected, first-generation hybrids (F1) and post-F1 hybrids, revealing the onset of extensive introgression and the potential for a hybrid swarm. Variation in the amplified COII domain of mitochondrial DNA indicated a strong directional bias of hybrids (88%) containing silver carp maternal lineages. Morphologically, F1 hybrids were often identifiable (88%) by the presence of twisted gill rakers, but post-F1 hybrids were difficult to identify with any appreciable certainty. This result creates concern where taxonomic assignment is critical for management or monitoring, warranting a more extensive and intensive examination of this phenomenon in North American waters. Finally, prior observations in aquaculture have shown reduced jumping behavior, fitness, and condition of fish resulting from post-F1 matings between these species. This is the first confirmed presence of wild post-F1 individuals of Asian carps in the United States and, although further monitoring is needed, a hybrid swarm may ultimately decrease invasion success as introgression continues.

AB - Asian carps are classified as either bighead carp Hypophthalmichthys nobilis or silver carp H. molitrix by multiple presumptively diagnostic morphological characteristics; however, hybrids pose a dilemma. Fish sharing the morphological characteristics of both species were observed in an Illinois River backwater (Calhoun County, Illinois) approximately 5 mi (8 km) upriver from the confluence with the Mississippi River as well as in two locations in Pool 26 of the Mississippi River (Madison County, Illinois). Biopsied tissues from individuals exhibiting mixed morphological features were analyzed at four diagnostic allozyme loci (ADH-1*, sMDH-A*, CK-A*, and sSOD-1*) via starch gel electrophoresis. This comparison revealed a high percentage of hybridization (22.5%) from an indiscriminate sample of 120 fish. Moreover, an unexpected percentage (12.5%) of individuals identified in the wild as either parental bighead carp or silver carp by gill raker morphology were genetically identified as hybrids. Finally, two levels of hybridization were detected, first-generation hybrids (F1) and post-F1 hybrids, revealing the onset of extensive introgression and the potential for a hybrid swarm. Variation in the amplified COII domain of mitochondrial DNA indicated a strong directional bias of hybrids (88%) containing silver carp maternal lineages. Morphologically, F1 hybrids were often identifiable (88%) by the presence of twisted gill rakers, but post-F1 hybrids were difficult to identify with any appreciable certainty. This result creates concern where taxonomic assignment is critical for management or monitoring, warranting a more extensive and intensive examination of this phenomenon in North American waters. Finally, prior observations in aquaculture have shown reduced jumping behavior, fitness, and condition of fish resulting from post-F1 matings between these species. This is the first confirmed presence of wild post-F1 individuals of Asian carps in the United States and, although further monitoring is needed, a hybrid swarm may ultimately decrease invasion success as introgression continues.

UR - http://www.scopus.com/inward/record.url?scp=83555160667&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=83555160667&partnerID=8YFLogxK

U2 - 10.1577/M10-053.1

DO - 10.1577/M10-053.1

M3 - Article

AN - SCOPUS:83555160667

VL - 30

SP - 1452

EP - 1461

JO - North American Journal of Fisheries Management

JF - North American Journal of Fisheries Management

SN - 0275-5947

IS - 6

ER -