Reproductive biology of invasive grass carp (Ctenopharyngodon idella) in two North American systems

Tammy Michelle Wilson; Matthew Ross Acre; Fred Williams; Robin D. Calfee; Christine M. Mayer; Robert L. Mapes; Chris M. Kemp; Ryan T. Young; Michael E. Byrne

doi:10.1111/jfb.70003

USGS · 70263858

Reproductive biology of invasive grass carp (Ctenopharyngodon idella) in two North American systems

Tammy Michelle Wilson·Matthew Ross Acre·Fred Williams·Robin D. Calfee·Christine M. Mayer·Robert L. Mapes·Chris M. Kemp·Ryan T. Young·Michael E. Byrne

View original source ↗Export metadata ↓

Abstract

Grass carp ( Ctenopharyngodon idella ) are nonnative, herbivorous freshwater fish that represent an ecological threat in North American waters. However, data are limited on reproductive biology specific to wild populations in midwestern North America, despite recent concern for grass carp establishment within the Great Lakes. Basic information on reproductive traits could be useful to determine reproductive potential, inform future population modelling and provide information to aid control efforts. Our objectives were to evaluate grass carp age-at-maturity, spawning season timing, fecundity type, developmental timing and spawning strategy. Additionally, we evaluated the reliability of the gonadosomatic index (GSI) as a proxy for identifying mature grass carp and compared body condition across study areas. We sampled grass carp in portions of the Mississippi River watershed within the state of Missouri and within the Lake Erie basin. Based on gonad histological samples ( n = 274), grass carp are batch spawners with indeterminate fecundity and asynchronous ovarian developmental timing. This allows flexibility in their spawning, exemplified by a protracted spawning season in Lake Erie (April to November) in temperatures ranging from 12.3 to 27.3°C. Minimum observed age-at-maturity for females in Missouri and for both males and females in the Lake Erie population was age-3 and age-2 for males in Missouri. Accuracy of GSI as a measure of maturity during the spawning season was 89.7% and 87.5%, for females and males, respectively. Compared to Missouri, grass carp in Lake Erie had a significantly higher body condition, and females ready to spawn had significantly higher GSI values, suggesting that the grass carp in Lake Erie are healthier and more fecund relative to Missouri and, if left uncontrolled, potentially have a high probability of establishment within the Great Lakes. The results of this study will allow managers to identify the reproductive status of grass carp in the field and more accurately estimate populations and reproductive potential.

Explore related subjects

Journal of Fish Biology Article

Source-reported bounding extent: 38.420958358947615° to 42.26314878528456° latitude; -92.3648115327897° to -80.6234858416417° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Tammy Michelle Wilson, Matthew Ross Acre, Fred Williams, Robin D. Calfee, Christine M. Mayer, Robert L. Mapes, Chris M. Kemp, Ryan T. Young, Michael E. Byrne. 2025-02-25. Reproductive biology of invasive grass carp (Ctenopharyngodon idella) in two North American systems. https://doi.org/10.1111/jfb.70003

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Black Carp Mylopharyngodon piceus reproductive development and maturation in the Mississippi River basin

Black Carp Mylopharyngodon piceus are native to most major east Asian drainages and are internationally cultured for use as a food-fish or a biological control for molluscs. We describe the reproductive biology of Black Carp from the growing invasive population in the Mississippi River basin through examination of incidental commercial fisheries and biologist captures. Our objectives were to assess (1) reproductive development by combined macroscopic and histological staging to compare reproductive maturation by total length, estimated age, and latitude; (2) population functions of gonadosomatic index, length and age, and weight and length relationships; and (3) absolute fecundity. We identified length as a better predictor of reproductive maturation than age, with variation among individuals, and between males and females, with higher probability of maturation anticipated for larger and older individuals predicted around 1050 mm total length (TL; 6 years) for females and 950 mm TL (5 years) for males ( n = 548). Proposed sizes and ages are representative minimum and should be interpreted with the understanding that spawning and recruitment success increase for older, more mature fish than in early stages. Observed growth rates were rapid relative to both native and introduced ranges. We confirmed that Black Carp are developmentally indeterminate batch spawners due to the simultaneous presence of advanced growth oocytes via histology and egg measurements, with preserved egg average diameters ranging from 0.395 to 3.215 mm ( n = 23). Absolute fecundity estimates ranged from 72,748 to 3,542,789 eggs across the 966 to 1412 mm TL size range of individuals, with substantial variability among individuals attributed to poor relative fecundity estimates. These results represent the first step in assessing the reproductive rates of Mississippi River Black Carp via the size of reproductive development and potential contributions through fecundity. The results and population rates presented here may be used or adapted for future studies on regional spawning phenology and reproductive development, or in population growth models for control.

Arkansas, Illinois, Indiana, Kentucky, Louisiana, ↗

USGS2026

Plasticity in the reproductive biology of Yellowstone cutthroat trout Oncorhynchus virginalis bouvieri in Yellowstone Lake following lake trout Salvelinus namaycush invasion

Yellowstone cutthroat trout Oncorhynchus virginalis bouvieri in Yellowstone Lake are the focus of intensive conservation efforts due to the threat of predation by invasive lake trout Salvelinus namaycush . Suppression gillnetting has reduced the abundance of predatory lake trout, and the Yellowstone cutthroat trout population is recovering. Long-term monitoring indicates the size structure of the population shifted following lake trout invasion, suggesting that reproductive demographic rates of Yellowstone cutthroat trout may have changed. Length at 50% probability of maturity, as assessed using histological analysis of gonadal tissue, was 479 mm (95% confidence interval [CI] 467–490 mm) for females and 406 mm (95% CI 386–430 mm) for males, compared to 330 mm for males and females historically. Currently, age at 50% probability of maturity is 6.6 for females and 5.4 for males. The rate of skipped spawning was 3% for females and 38% for males. Mean absolute fecundity was 2897 ovarian follicles/individual at present compared to 1141 ovarian follicles/individual before lake trout invasion. Mean relative fecundity was 2157 ovarian follicles/kg. This research illustrates the plasticity in the reproductive strategies of fishes as a result of an invasive species. Understanding the reproductive biology of fish populations is vital for effective fisheries management, and these results are integral to a population model that can be used to develop new conservation benchmarks for Yellowstone cutthroat trout.

Wyoming↗

USGS2025

Too hot for comfort: Elevated temperatures influence gene expression and exceed thermal tolerance of bigmouth shiners, Ericymba dorsalis

Environmental and associated ecosystem change may affect the persistence of fish species based on their ability to adapt to changing conditions, including decreasing flows and rising water temperatures. Exceeding the thermal tolerances of stream fish will likely result in a loss of ability to maintain metabolic processes. We evaluated the critical thermal maximum (CTmax) of bigmouth shiner ( Ericymba dorsalis ) and analysed the expression of heat shock protein 70 messenger RNA (mRNA) (HSP70) to quantify a thermal stress response over a gradient of temperatures (25°C–31°C). E. dorsalis HSP70 mRNA expression was upregulated in response to temperatures >25°C, indicating a stress response. This study supports the existence of a thermal stress threshold for E. dorsalis . The frequency at which this threshold is exceeded may increase under forecasted future climate scenarios for Nebraska.

Nebraska↗