Lethal Oxygen Thresholds for Certain Temporary Pond Invertebrates and Their Applicability to Field Situations

Abstract

The normal dissolved oxygen patterns in certain temporary heterotophic pools in southeastern Louisiana are characterizd by relatively high values after initial flooding followed by a gradual decline to as low as 10% saturation as the pond ages. Laboratory delimitation of lethal oxygen thresholds for several characteristic temporary pond invertebrates revealed LD 50's of 0.1—0.4 ppm under test conditions. An unusual 8—day period of complete subsurface oxygen depletion during summer flooding in one such pond is described. Except for the conchostracans, there was little adverse effet on the macrofauna. This is attributed to the seeking of the partly oxygenated surface layer of the pond by the animals.

Factors affecting the hatching ofStreptocephalus macrourus Daday (Crustacea; Eubranchiopoda) eggs

“…He found that newly hatched L. polyphemus from eggs incubated at 35 C had a lower ash free dry mass than those from eggs incubated at 30 C, and this was a result of greater consumption of yolk by the embryo at the higher temperature. Dissolved oxygen tensions lower than 0.5 mg 1-have been shown to inhibit hatching of the eggs of Streptocephalus seali (Moore & Burn, 1968) and Branchinecta mackini (Brown & Carpelan, 1973). Moore & Burn (1968) also showed that dissolved oxygen tensions of lower the 0.5 mg 1 -1 caused total mortality amongst S. seali.…”

“…Dissolved oxygen tensions lower than 0.5 mg 1-have been shown to inhibit hatching of the eggs of Streptocephalus seali (Moore & Burn, 1968) and Branchinecta mackini (Brown & Carpelan, 1973). Moore & Burn (1968) also showed that dissolved oxygen tensions of lower the 0.5 mg 1 -1 caused total mortality amongst S. seali. This was not the case with S. macrourus, as the eggs were hatched and the nauplii survived at dissolved oxygen tensions of less then 0.5 mg 1 -.…”

Annual Metabolism of a Temporary Pond Ecosystem

“…Such ponds have been well-studied in terms of their species composition with special attention to the adaptations of organisms to seasonal drying and refilling processes (Mozley, 1932;Kenk, 1949;Rzoska, 1961 ;Marga vio, 1963;Moore and Burn, 1968;Cox and Young, 1974;Bishop, 1974). Few attempts have been made to investigate the whole system functioning of temporary ponds.…”

Lacustrine sequences in an early Mesozoic rift basin: Culpeper Basin, Virginia, USA

“…Dysaerobic conditions (0.1-1.0 ml/l dissolved oxygen) are capable of supporting the invertebrates commonly present in these black shales. Conchostracans can tolerate waters with dissolved oxygen content as low as 0.3 ml/1 at temperatures of 23~ in the laboratory (Moore & Burn 1968).…”