Schmitt et al.: Modeling the predation dynamics of invasive Ictalurus furcatus in Chesapeake Bay 
283 
April May June July Aug. Sep. Oct. 
Month 
Figure 3 
Predictions from the generalized additive model for predation 
on imperiled alosines by blue catfish ( Ictalurus furcatus), cal¬ 
culated as probability of occurrence in a catfish stomach, by 
salinity, predator total length, month, and river. All predictive 
factors were significant (P<0.05). Imperiled alosines include 
the American shad {Alosa sapidissima), blueback herring 
(A. aestivalis), and alewife (A. pseudoharengus). Blue catfish 
were collected in the James, Pamunkey, Mattaponi, and Rap¬ 
pahannock Rivers in eastern Virginia during 2013-2016. 
Salinity 
Predator total length (mm) 
Month 
Figure 4 
Predictions from the generalized additive model for pre¬ 
dation on blue crab (Callinectes sapidus ) by blue catfish 
(.Ictalurus furcatus), calculated as probability of occurrence 
in a catfish stomach, by salinity, predator total length, 
month, and river. All predictive factors used in the model 
were significant (P<0.05). Blue catfish were collected in 
the James, Pamunkey, Mattaponi, and Rappahannock Riv¬ 
ers in eastern Virginia from April through October during 
2013-2016. 
