Further investigatiions on the influence of sediment-associated phthalate esters (DEHP and DINP) on hatching and survival of the moorfrog Rana arvalis

• The hatchability and survival of eggs from Moorfrog (Rana arvalis) and condition and growth of hatched larvae were examined in presence of various concentrations of di-2-ethylhexyl phtalate (DEHP) in the sediment. Two types of sediment have been used in the biological assay. Fine sediment comprising mostly degraded organic material and a coarse type consisting of higher degree at two temperatures 10 and S°C. Each test series consisted of three different concentrations of spiked sediments, 1000, 300 and 100 mg DEHP/k:g dw together with solvent (acetone) control and control. Five replicants were examined for each of the different treatments.  Exposure to DEHP conducted at 1ooc showed no significant effect on the hatching frequency and median hatching  time for all tested concentrations, compared to the control groups. soc, except that the lower temperature gave a significant  decrease in hatching frequency for all tested concentrations compared to the 10°C series. The lower hatchability at the lower temperature indicated that an unnaturally high stress factor was added to the experiments when exposure was conducted at the lower temperature. Larval mortality was less than 2 percent, in all tested concentrations and was not correlated  to the temperature. There was no significant  difference  in mortality among the various treatments. The visual morphological deformities  were also low in all tested concentrations and no significant difference  could be established. Growth measurements showed no significant difference between the sediment types or a dose related difference within the 10°C and S°C experiments. Parallel to DEHP, an identical experiment with diisononyl phthalate (DINP) was performed in the same manner at 10°C. Exposure to DINP  showed no significant effect on the hatching  frequency and median hatching  time for all tested concentrations, compared  to the control groups. There was no significant difference in mortality and growth among the various treatments. Visual morphological deformities were also low in the controls as well as in all tested concentrations and no significant difference could be established.

• This report is only available in English.

Keyword

Frog

egg

larvae

Publication and Content Type

vet (subject category)

rap (subject category)