Effects of Environmental Factors on Larval Development of Marine Invertebrates: Annual Progress Report. Part III. Regeneration as an Indicator of Environmental Stress.

摘要

Megalopae of the mud crab, Rithropanopeus harriii, within the control series were maintained with both chelae intact, as well as with one chela autotomized, in 20 parts per thousand seawater and in the ''acetone control.'' Percent survival to crab III for larvae of the control series, and larvae maintained in four concentrations of the herbicide, Alachlor is presented. As the concentration of Alachlor increases, the percent survival decreases. A comparison of these same levels of concentration of Alachlor as they relate to the time of ecdysis is shown. There is no statistically significant impact on molting. The interval between crab I and crab II was also unaffected by the levels of Alachlor used. Normal regeneration of the autotomized claw of the megalopa in the control series occurred in 100% of the larvae. As the larvae were exposed to Alachlor of different concentrations, the percent normal regeneration decreased and the percent abnormal regeneration increased. The process of regeneration can be used as an extremely sensitive indicator of sublethal levels for a variety of contaminants. A second aspect of the research as originally planned was to determine the effect of carbamates on regeneration of chelae in megalopae and early juveniles of the mud crab Rhithropanopeus harrisii. (ERA citation 13:055253)