Drift of Embryonic and Larval Fishes, EspeciallyLepomis gibbosus(L.), in the Upper Rhone River

Abstract
The drift of embryonic and larval fishes in the main channel of the Upper Rhone River, France, was monitored continuousty over a 48-h period in mid-July 1985. The relative abundances of 8 species of fry did not change; the free embryos and larvae of L. gibbosus end the larvae of Gobio gobio were dominant. Fry were more abundant in near-bottom samples during the day and more abundant in surface samples at night. Changes in L. gibbosus density corresponded to changes in light intensity.