Tropical fish medicine. Biopsy and rapid postmortem techniques for diagnosing diseases of fish.

Biopsy and rapid postmortem techniques are simple to perform with commonly available instruments. Because the skin and gills are the target organs for so many infectious agents, biopsy is a very useful tool in pet fish medicine. The major requisite for successful diagnosis using biopsy materials is the ability to recognize different taxonomic groups of pathogens. Many of these pathogens may be present in clinically normal individuals, and their importance must be interpreted with other clinical findings. Rapid postmortem techniques can identify several common systemic diseases affecting pet fish. The usefulness of these procedures is highly dependent on the state of tissue preservation of the specimens presented.