Aquatic Invertebrates

This chapter is an overview of clinical information for common species in the aquarium trade. Much information was extracted from data of case-control studies rather than from studies to establish normal values. The resulting biases, including small sample size, should be accounted for when using these values. Furthermore, techniques and protocols used to monitor health parameters in vertebrates have rarely been evaluated or validated for invertebrates. However, many of these techniques are useful in assessment of alterations in homeostasis of aquatic invertebrates. General diagnostic testing useful for many aquatic invertebrates include assessment of hemolymph color and clotting, hemocyte counts, and species-specific determination of hemolymph biochemical analytes, enzymes, and gases. The chapter focuses on interpretation of the characteristics of hemolymph in display animals. Assessment of clinicopathologic parameters of aquatic invertebrates should coincide with assessment of environmental parameters, such as water quality, to render these values most useful.