Abstract
This issue of Veterinary Pathology presents a series of articles on diseases of aquatic animals. These animals represent an integral component of the species diversity on this planet. Articles in this special focus issue reflect this amazing diversity and criticality of aquatic animals in maintaining the integrity of the aquatic ecosystem. Aquatic animals play an essential role as monitors of the health and wholesomeness of our aquatic environment. They are an important food source. They enrich our human existence with their beauty, grace, and sometimes downright weirdness. Aquarium exhibits of an unseen world are an ever-popular entertainment and education source. Given the importance of aquatic animals in our lives and in the world as a whole, threats to aquatic existence, including disease and environmental issues, must be identified and methods developed to ensure the continuation and sustainability of these amazing life forms well into the future.
Today, strandings and deaths of aquatic animals are increasingly publicized in the lay press, creating substantial consternation in the public arena. This consternation derives in part from concern for the species and creates uncertainty about the safety of the Earth’s (as well as the individual’s) water systems. As such, this special issue could not be more timely. It addresses some of the causes of mass deaths and disease, as well as the challenges in identifying disease causality in aquatic animals.
Although the depth and breadth of knowledge of the myriad aquatic species diseases lag behind that of our domestic species, our understanding of the natural biology of aquatic species is growing exponentially. The articles in this issue highlight the growing sophistication of the diagnostic tools leveraged by the aquatic animal pathologist. Although the technologies applied in aquatic animal pathology are typically the same as those used in domestic animal, laboratory animal, and human pathology, their application often presents technical challenges when used in novel species. As a complicating factor, training programs for aquatic animal pathologists are quite limited compared with similar programs for domestic and laboratory animals. In support of the aquatic animal diagnostic pathologist, this issue provides guidance for recognition of some common diseases of common aquatic animal species, as well as diagnostic criteria for the diseases presented.
The issue begins with reviews across multiple disease entities in specific species: Bonar et al address pathologic findings in sea dragons, while Garner presents diseases occurring in sharks; a subsequent article addresses neoplastic disease in fish, in which Coffee et al review retroviral tumors.
Four articles cover in great depth specific diseases that may be population-limiting factors: Smolowitz presents the effect of Perkinsus marinus in oysters, Schaeffer et al address Carnobacterium maltaromaticum–like bacterial meningoencephalitis in sharks, Spitsbergen et al discuss an epizootic of neoplasia in trout, and LaDouceur et al evaluate ulcerative umbrella injury in jellyfish.
Degenerative joint diseases can also be a problem in aquatic animals. In this issue, Burns et al describe tumoral calcinosis in turtles, and Battison communicates about gout in lobsters.
Finally, there is growing attention on fish as laboratory models for studies of human disease. Two articles specifically present zebrafish models of human disease: Borst et al define a zebrafish model as a screen for attenuation of pathogenic streptococci, while Shive defines the utility of zebrafish in the study of human cancers. Pathologists are integrally involved in validating the usefulness and application of these new models for comparative biology and toxicologic assessment.
It is hoped that this issue presents the start of a growing body of knowledge for veterinary pathologists. As the role of veterinary pathology in aquatic medicine continues to expand, we hope you find this special issue both an inspiration and an informative resource.