The crevalle jack (Caranx hippos) is a commonly kept aquarium species, in addition to being important in fisheries and game fishing. Given the numbers of this and related species in managed populations, tissue enzyme activities are important for the accurate interpretation of biochemistry data when encountered as patients.1,2 The objectives of this study were to describe tissue enzyme activities in five organs (liver, small intestine, kidney, heart, and skeletal muscle) and to determine the effects of sample storage on enzyme activities in captive adult crevalle jacks. Forty fish were anesthetized, phlebotomized, humanely euthanized, and necropsied. Tissue samples were immediately processed to obtain supernatant for enzyme activity measurements, including alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transferase (GGT), lactate dehydrogenase (LDH), and creatine kinase (CK). One supernatant aliquot was analyzed within 24 hours of collection, and a second aliquot was immediately frozen at -80°C to be processed approximately 30 days later. ALP had highest activities in liver, kidney, and lesser in intestine. ALT showed highest activities in the liver, while GGT was highest in kidney. AST had highest activities in heart muscle and liver. LDH and CK showed highest activities in skeletal muscle, with low activities of LDH also present in heart muscle. Storage did alter some enzyme activities, but not to a degree that would affect clinical interpretation. The results of this study offer further understanding of tissue enzyme activity patterns in a teleost species with clinical applications when interpreting biochemistry data.
The authors wish to thank the husbandry staff and veterinary technicians of Georgia Aquarium who assisted with the sample collection and processing. Funding for this research was made possible by Georgia Aquarium.
1. Anderson E, Stoskopf M, Morris J Jr, Clarke E, Harms C. Hematology, plasma biochemistry, and tissue enzyme activities of invasive red lionfish captured off North Carolina, USA. Journal of Aquatic Animal Health. 2010;22(4):266–273.
2. Clarke EO, Christiansen EF, Stoskopf M, Harms C. Tissue enzyme activity in black sea bass (Centropristis striata) captured off North Carolina, USA. International Association for Aquatic Animal Medicine Meeting and Conference; 2012.