Hematology and Plasma Chemistry Values for Production Tilapia (Oreochromis hybrid) Raised in a Recirculation System

Abstract

Tilapia are a frequently aquacultured fish, yet little is known about their normal physiology and response to disease. To assess specific diseases in mammals, blood constituents are routinely analyzed and compared to previously determined standardized values. Research to establish hematologic values for normal healthy fish is required before blood analysis can be used for diagnostic purposes in fishes. This study determined hematology and plasma chemistry values for production tilapia (Oreochromis hybrids) raised in a recirculation system. Using standard clinical techniques, the following hematologic parameters were determined: PCV (packed cell volume), plasma protein and MCV (mean cell volume) values; and erythrocyte, leukocyte, lymphocyte (small and large), neutrophil, monocyte, eosinophil, thrombocyte-like-cell, and thrombocyte numbers. Additionally, the following plasma chemistry values were determined: total protein, albumin, globulin, creatinine, total bilirubin, ALP (alkaline phosphatase), AST (aspartate aminotransferase), sodium, potassium, chloride, calcium, phosphorus, magnesium, glucose, cholesterol, ammonia and osmolality. Analysis of blood parameters can enhance production of hybrid tilapia by providing a means for the early detection of infectious diseases, and by assisting in the identification of sub-clinical conditions affecting production performance.

Hematology and plasma chemistry reference intervals for cultured shortnose sturgeon (Acipenser brevirostrum)

“…Neutrophil counts have not been published previously for this or other Acipenser sp, though Jenkins45 reported neutrophil percentages ranging from 29 to 62% in the pallid sturgeon, S albus , compared to neutrophil percentages of 30% in shortnose sturgeon in this study. Another interesting observation in the leukogram was the presence of the thrombocyte‐like cell in the shortnose sturgeon, a cell type which has been previously identified in hybrid striped bass and tilapia 17,20,21…”

“…In individual fish, genetic variation, age, stage of development, reproductive state, sex, and activity level have been documented to affect hematologic values. [17][18][19][20][21][22][23][24][25][26][27][28][29] Reference intervals have been established for a few fish species. 17,21,25,26,28 However, only a few hematologic values have been determined in shortnose sturgeon in studies evaluating physiologic responses to exercise and salinity changes.…”

“…Plasma protein is mainly altered by changes in plasma volume, which in fish may be observed with prolonged starvation or stress. 18,24 The method of manually determining total leukocyte and differential counts has been recommended for use with avian 44 and fish blood [17][18][19][20][21][22] because nucleated erythrocytes prevent accurate enumeration using automated analysis. 16 The result-ing leukogram of the shortnose sturgeon was fairly typical of other fish species.…”

“…Another interesting observation in the leukogram was the presence of the thrombocyte-like cell in the shortnose sturgeon, a cell type which has been previously identified in hybrid striped bass and tilapia. 17,20,21 The broad range for some of the reference intervals, particularly for the total WBC count, lymphocyte count, and thrombocyte count, may be attributed in part to the production aquaculture settings. Reference intervals ''tighten up'' when determined for fish held under laboratory conditions.…”