The Failure Of Largemouth Bass, Micropterus Salmoides Floridanus (Lesueur), To Spawn In Eutrophic, Over-Crowded Environments

Nonreproductive populations of adult largemouth bass have been found in a number of lakes. In all cases, these environments are characterized as highly eutrophic and over-crowded with bream and forage species. Reproductive failure was demonstrated to be due to a refusal ofthe adult population to spawn. Ripened ovaries were retained long after the spawning season and the deteriorated ova eventually reabsorbed. In some cases, only a portion of the adult largemouth bass population spawned, yet produced substantial yearclasses. Reproductive inhibition was attributed to the excretion and build up of a hormone like repressive factor by over-crowded bream and forage species. Largemouth bass reproduction was induced by Human Chorionic Gonadotrophin injections in at least I and perhaps 2 nonreproductive lakes. Eutrophic, over-crowded conditions, identical to those found in non-productive lakes, were created in four hatchery ponds. Stocked pairs of largemouth bass failed to spawn in a manner identical to that in non-reproductive lakes.

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