Amy George
Science and Products
Early Life History of Bighead, Silver, Black, and Grass Carps
Grass, bighead, black, and silver carps spawn in turbulent rivers and their eggs develop and hatch while drifting downriver. The larvae also have a short period of developing in the drift, and then they must swim from the river and find appropriate low- or no-flow nursery areas. Rivers which are not long enough, turbulent enough, or without nursery areas in the correct locations...
Physical characteristics and simulated transport of pallid sturgeon and shovelnose sturgeon eggs
The imperiled pallid sturgeon (Scaphirhynchus albus) and closely related, but more common, shovelnose sturgeon (S. platorynchus) are believed to broadcast adhesive, demersal eggs in the current and over coarse substrate in turbid rivers of the North American midcontinent. It has been hypothesized that eggs settle immediately following...
Chojnacki, Kimberly; Erwin, Susannah O.; George, Amy E.; Candrl, James; Jacobson, Robert B.; Delonay, Aaron J. Influence of turbulence and in-stream structures on the transport and survival of grass carp eggs and larvae at various developmental stages
Understanding the response of grass carp to flow and turbulence regimes during early life stages is fundamental to monitoring and controlling their spread. A comprehensive set of hydrodynamic experiments was conducted with live grass carp eggs and larvae, to better understand their drifting and swimming patterns with 3 different in-stream...
Prada, Andres F.; George, Amy E.; Stahlschmidt, Benjamin H.; Jackson, P. Ryan; Chapman, Duane C.; Tinoco, Rafael O. Survival and drifting patterns of grass carp eggs and larvae in response to interactions with flow and sediment in a laboratory flume
A series of laboratory experiments was conducted to better understand the behavior of grass carp eggs and larvae in moving water in order to develop and implement new strategies for control and prediction of their dispersal and drift at early life stages. Settling velocity and density of a representative sample of eggs were estimated, and three...
Prada, Andres F.; George, Amy E.; Stahlschmidt, Benjamin H.; Chapman, Duane C.; Tinoco, Rafael O. Ontogenetic changes in swimming speed of silver carp, bighead carp, and grass carp larvae: implications for larval dispersal
Bighead, silver, and grass carps are invasive in the waterways of central North America, and grass carp reproduction in tributaries of the Great Lakes has now been documented. Questions about recruitment potential motivate a need for accurate models of egg and larval dispersal. Quantitative data on swimming behaviors and capabilities during early...
George, Amy E.; Garcia, Tatiana; Stahlschmidt, Benjamin H.; Chapman, Duane C. Evidence of Asian carp spawning upstream of a key choke point in the Mississippi River
Bighead Carp Hypophthalmichthys nobilis, Silver Carp H. molitrix, and Grass Carp Ctenopharyngodon idella(collectively termed “Asian carp”) were introduced into North America during the 1960s and 1970s and have become established in the lower Mississippi River basin. Previously published evidence for spawning of these species in the...
Larson, James H.; Knights, Brent C.; McCalla, S. Grace; Monroe, Emy; Tuttle-Lau, Maren T.; Chapman, Duane C.; George, Amy E.; Vallazza, Jon; Amberg, Jon J. Comparison of size, terminal fall velocity, and density of bighead carp, silver carp, and grass carp eggs for use in drift modeling
Invasive Asian carp established in the United States spawn in the turbulent water of rivers, and their eggs and early larvae develop while drifting in the current. The eggs, which are believed to perish if they settle before hatching, are slightly denser than water and are held in suspension by water turbulence. It is possible to use egg drift...
George, Amy E.; Garcia, Tatiana; Chapman, Duane C. Genetic analysis shows that morphology alone cannot distinguish asian carp eggs from those of other cyprinid species
Fish eggs and embryos (hereafter collectively referred to as “eggs”) were collected in the upper Mississippi River main stem (~300 km upstream of previously reported spawning by invasive Asian carp) during summer 2013. Based on previously published morphological characteristics, the eggs were identified as belonging to Asian carp. A subsample of...
Larson, James H.; McCalla, S. Grace; Chapman, Duane C.; Rees, Christopher B.; Knights, Brent C.; Vallazza, Jon; George, Amy E.; Richardson, William B.; Amberg, Jon J. Identifying sturgeon spawning locations through back-calculations of drift
Unfavorable spawning habitat conditions have been identified as a potential limiting factor for recovery of the endangered pallid sturgeon on the Missouri River and its tributaries. After successful spawning, incubation, and hatching, sturgeon free embryos passively drift downstream and are sometimes captured by sampling crews. While spawning...
Bulliner, Edward A.; Erwin, Susannah O.; Jacobson, Robert B.; Chojnacki, Kimberly A.; George, Amy E.; Delonay, Aaron J. Effects of sediment burial on grass carp, Ctenopharyngodon idella (Valenciennes,1844), eggs
It is thought that grass carp (Ctenopharyngodon idella) eggs must remain suspended in the water column in order to hatch successfully. Using sand, the effects of varying sediment levels on grass carp eggs were tested at different developmental states and temperatures. Survival was high (15–35%, depending on temperature and trial) in the...
George, Amy E.; Chapman, Duane C.; Deters, Joseph E.; Erwin, Susannah O.; Hayer, Cari-Ann Embryonic and larval development and early behavior in grass carp, Ctenopharyngodon idella: implications for recruitment in rivers
With recent findings of grass carp Ctenopharyngodon idella in tributaries of the Great Lakes, information on developmental rate and larval behavior is critical to efforts to assess the potential for establishment within the tributaries of that region. In laboratory experiments, grass carp were spawned and eggs and larvae reared at two temperature...
George, Amy E.; Chapman, Duane C. Aspects of embryonic and larval development in bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix
As bighead carp Hypophthalmichthys nobilis and silver carp H. molitrix (the bigheaded carps) are poised to enter the Laurentian Great Lakes and potentially damage the region’s economically important fishery, information on developmental rates and behaviors of carps is critical to assessing their ability to establish sustainable populations within...
George, Amy E.; Chapman, Duane C.
Developmental rate and behavior of early life stages of bighead carp and silver carp
The early life stages of Asian carp are well described by Yi and others (1988), but since these descriptions are represented by line drawings based only on live individuals and lacked temperature controls, further information on developmental time and stages is of use to expand understanding of early life stages of these species. Bighead carp and...
Chapman, Duane C.; George, Amy E.