DIDSON files (see Archived Material; from 2007 pond trials at Delaware State University) used to evaluate automated estimates of fish length (TL, total length; FL, fork length) from Echoview software for Atlantic sturgeon Acipenser oxyrinchus oxyrinchus (ATS), striped bass Morone saxatilis (STB), white perch Morone americana (WPC), and channel catfish Ictalurus punctatus (CCAT). For comparison, range, manual estimates of TL, and aspect angle using Sound Metrics software are given for observer 1.