Secondary production of selected invertebrates in an ephemeral pond

Between September, 1970 and August, 1971, an ecological study was made of a small ephemeral pond located in Brazos County, south-central Texas. The pond exhibited swift succession of physico-chemical characteristics between filling and drying. As drying proceeded, there was a general decrease in the total amount of dissolved materials. Concentrations of most materials increased; however, the concentrations of ortho-phosphate and nitrate decreased. Rainfall and surface runoff modified the above patters by diluting the concentrations of most materials, but increasing nitrate and ortho-phosphate. Biotic succession was rapid. Typical ephemeral pond species such as rotifers, copepods, anostracans, and mosquito larvae appeared first. These were followed by amphipods, isopods, insects, and other forms more characteristic of permanent ponds. ..