Anesthetic, Relaxant, and Narcotizing Agents for Aquatic Invertebrates CONTENTS and INTRODUCTION |
Various agents can induce aquatic invertebrates to enter physiological states described as "relaxation," "anesthesia," and "narcosis." The objective of such treatment is to reduce or eliminate responses to stimuli, preventing reactions that might interfere with experimental research or defeat other objectives. For example, clams that close tightly when touched may now be kept open, worms that typically contract may remain elongated, and organisms normally stressed by handling and transport may now be unaffected. With appropriate agents and procedures, the induced state is reversible upon return to normal physiological conditions. Anesthesia and narcosis are terms best understood for vertebrates, implying induction of a sleeplike state and loss of sensory perception. For invertebrates, however, the physiological mechanisms by which various agents induce comparable states are often poorly understood. Such mechanisms are not reviewed here at present.
This compendium is devoted to invertebrates that are valuable in aquaculture and in biomedical and ecological research, with an emphasis on marine species (Table 1). The major objective is to provide a rapid sampling of representative organisms and agents. Original literature citations are given for most entries, as well as notes for certain methods and older sources (Literature and Notes). Published descriptions of these procedures have great variability in level of detail; some that are rather cursory are nevertheless presented because of potential value for further development. An additional feature is the inclusion of previously unpublished methods, contributed by active researchers and cited in Table 1 as "Personal Communications" (potential contributors and users: please see NOTE and NOTICE, below).
Organisms are listed alphabetically by phylum in Table 1, an active, ongoing compilation. It includes Annelids, Arthropods, Cnidaria, Echinoderms, Molluscs, and Other Aquatic Invertebrates. Older data on invertebrate "narcotizing" agents can be obtained from Russell (1963), available among the online Classic Resources provided by Biological Bulletin Publications. For further information on such agents, the comprehensive work by Ross and Ross (1999) is recommended.