Invertebrate Cells as Targets for Hazardous Substances

Abstract

Electron microscopy is an established diagnostic method in pathology of man as well as of vertebrate animals. During the last decade, ultrastructural studies have also been performed in invertebrates to elucidate cellular injuries caused by hazardous substances (BAYNE et al. 1985, MOORE 1985, STORCH 1988, HOPKIN 1989). The interest in invertebrates has increased due to their suitability to monitor environmental pollution. For example field and laboratory studies have been performed using the bivalve Mytilus edulis or the gastropod Littorina littorea as indicator of chemical contamination (AUFFRET 1988, CAJARAVILLE et al. 1989, CAJARAVILLE et al. 1990, MOORE 1988). Additionally, many invertebrates, such as aphids, grasshoppers, caterpillars or slugs are of significance as pest organisms in agriculture. Others, in most cases insects like the Ichneumonidae or Planipennia, are of increasing importance in biological or integrated pest control.

In a series of laboratory tests we examined cellular reactions in a variety of invertebrates after exposure to environmentally relevant toxicants, like metals or pesticides. The following animals were selected for their environmental or commercial significance:

-the shrimp, Penaeus monodon (Crustacea, Decapoda), as a commercially important aquaculture species which is impaired by environmental toxicants,

-the flatworm, Polycelis felina (Turbellaria, Tricladida), a common inhabitant of central European brooks, which is menaced by acid rain and subsequently released aluminium,

-the millipede, Cylindroiulus punctatus (Diplopoda, Julida), as an important animal of the soil macrofauna, involved in the decomposition of organic material,

-the moss mite, Nothrus silvestris (Acari, Oribatida), as a representative of saprophagous soil animals occurring in high population densities,

-the slug, Deroceras reticulatum (Gastropoda, Pulmonata), which is an important pest organism in European agriculture,

-and Chrysoperla carnea (Insecta, Planipennia), as a beneficial species used in the biological control of aphids.

It was the aim of this study to demonstrate the suitability of electron microscopy for evaluating the effects of hazardous substances on cells of invertebrate tissues.