C. H. Pennington

A study was conducted from April through October 1980 to characterize seasonal changes in distribution, diversity, and abundance of ichthyoplankton within the Cracraft dike field in the lower Mississippi River. During high river stages (April through June), diversity and abundance of larval fishes were greater at open-water than nearshore stations. Under moderate to low river stages (July through October), diversity was low and greatest densities of larval fishes were observed along the shoreline inside the middle bar rather than in the open-water.

Larval fish were collected in the Lower Mississippi River at Sunnyside Revetment on 27-28 June 1978 to investigate diel fluctuations in diversity and ahundance and to determine whethersamples collected for 1-2 hours and from opposite sides of the hoat can he considered replicate samples for a time period. Numher of taxa and density differed significantly (P < 0.01) hetween time periods of the diel cycle. Numher of taxa and density were greatest at dusk. Twelve taxa were collected only in dusk, night, and dawn samples. Aplodinotus grunniens, Carpiodes spp. and c1upeids accounted for 95...