Seasonal patterns of respiration, gill ventilation, and hematological characteristics in the striped mullet, Mugil cephalus L.

The striped mullet, M. cephalus, endures pronounced diurnal and seasonal temperature changes in the shallow bay system of the Texas coast. The mullet reponds to its temperature induced changes in metabolic oxygen demand with a pattern of respiratory, ventilatory, and hematological adjustments. These variables were measured at 14.5 degree and 28.5 degree C during each season to sepatate seasonal form short term responses. In van Dam-type respirometers, oxygen consumption rates remained at essentially constant levels at each temperature through the year (x@u-=42.84 ml 0 sub(2)/kg/bh at 14.5 degrees C and 141./83 ml O sub(2)/kg/h at 28.5 degrees C). Gill ventilitory flows, frequencies and stroke volumes also remained seasonally constant at each temperature. Seasonal differences at each temperature regime were most evident in the blood characteristics of hemoglobin concentrations and hematocrit.; $