Use of a Restored Central California Floodplain by Larvae of Native and Alien Fishes

Abstract

Abstract.—We sampled larval fish in 1999 and 2001 on a restored floodplain along the lower Cosumnes River, California, from the onset of flooding to when the sites dried or when larval fish became rare. We collected more than 13,000 fish, of which prickly sculpin Cottus asper made up the majority (73%). Eleven species made up 99 % of the catch. Three native fishes (prickly sculpin, Sacramento sucker Catostomus occidentalis, and splittail Pogonichthys macrolepidotus) and two alien species (common carp Cyprinus carpio and bigscale logperch Percina macrolepida) were associated with higher inundation and cool temperatures of early spring. In contrast, five alien taxa, sunfish Lepomis spp., largemouth bass Micropterus salmoides, crappie Pomoxis spp., golden shiner Notemigonus crysoleucas, and inland silverside Menidia beryllina, were associated with less inundation and warmer water temperatures. One native species, Sacramento blackfish Orthodon microlepidotus, was also associated with these conditions. Species did not show strong associations with habitat because of different spawning times of adults and expansion and contraction of flood waters. Most species could be found at all sites throughout flooded habitat, although river and floodplain spawning fishes usually dominated sites