Effect of Transient Acid Spikes on Developmental Stages of <i>Lepomis</i>Fishes

The effects of transient acid spikes on development of Lepomis sunfish were studied by combining field work with laboratory studies. Lepomis sunfish eggs were collected from rocks on nests in two freshwater ponds and tested for their resistance to laboratory induced transient acid spikes. Fertilized eggs on rocks within the same nest were used for each pH transient experiment. Egg masses on one rock from the nest were used as a control while egg masses on another rock were exposed to transient acid spikes. Various stages of development showed different responses to the acidic effects. The major stages studied were fertilized egg, hatched with attached yolk sac, and free swimming with gills. The acid sensitivity followed development stages with the most acid sensitive stage being free swimming with gills. This fieldwork-laboratory data chain supports earlier field studies, providing the final link in an evidentiary chain showing the effects of transient acid spikes on Lepomis hatching profiles in freshwater ponds.