Abstract

Frogfish (Antennariidae) are a popular display animal in aquariums due to their unique anatomy and cryptic coloration. A lack of knowledge exists concerning common diseases encountered in frogfish. A retrospective review of clinical records, gross pathology, and histopathology was conducted on captive frogfish specimens at the Shedd Aquarium from 2002 through 2015 to identify causes of morbidity and mortality. The study population consisted of 26 individuals (three alive at time of data collection) representing six species of frogfish (Antennarius hispidus, A. maculatus, A. commerson, A. biocellatus, A. avelonis, and A. bermudensis). Gill biopsies, tissues, and whole body specimens were submitted for necropsy and histopathology. Endocardial hypertrophy, melanomacrophage hyperplasia, and hepatic lipid deposition were found to be common reactions to illness in the frogfish. Review of histopathology records revealed that sepsis was the most common cause of mortality at 47.8% (11 of 23 cases). The two most common causes of sepsis were fungus (55%, 6 of 11 cases) and bacteria (45%, 5 of 11 cases). Exophiala species were the most common fungal infection, whereas Vibrio species were the most common bacterial etiology. Common parasites included the pathogenic Cryptocaryon irritans and incidental Myxosporidia and Microsporidia species. The findings of this study will allow for improved care and management of frogfish in an aquarium setting.

Acknowledgments

Authors would like to thank The University of Illinois Zoological Pathology Program. Thank you to the Shedd Aquarium Animal Health and Fishes Departments with special thanks to the veterinary technicians and aquarists.