Notes: Disease-Associated Blood Changes and Normal Seasonal Hematological Variation in Winter Flounder in the Hudson–Raritan Estuary

Abstract

Abstract Hematological variables of diseased and apparently healthy winter flounder Pleuronectes americanus were evaluated during fin rot epizootics in the Hudson–Raritan estuary, New York–New Jersey. Most diseased fish had significantly lower (average, 43% lower; P < 0.05) levels of hemoglobin, erythrocytes, hematocrit, and plasma protein than healthy fish; blood deficiencies were more frequent among juveniles (ages 1 and 2) than adults. The results indicate that the disease had severe consequences for this species. Normal seasonal variation in winter flounder hematology was determined by assessment of healthy fish through an annual cycle, Hemoglobin, erythrocyte, and hematocrit values were high between October and April–May and low between June and September. Plasma protein levels were high in June–December (January data were not obtained), and low in February–May. Juveniles and adults differed significantly in levels of plasma protein through the annual cycle. Temporary (1–7-month) differences in hemog...