Effects of acute gamma irradiation on the blood constitutents of pinfish,Lagodon rhomboides

Adult pinfish,Lagodon rhomboides, were irradiated with a dose of either 2,000 or 5,000 R of gamma radiation. Changes in cellular blood components were followed for 34 days in fish receiving 2,000 R and for the 7 days that fish receiving 5,000 R survived. Neither radiation dose had much effect on erythrocyte numbers, hematocrit values, or hemoglobin levels. The number of thrombocytes in both irradiated groups decreased for 1 week and then slowly recovered in fish that received 2,000 R. Leucocytosis occurred 6 hours after irradiation, followed by leucopenia, which was maximal on the 3rd day. In fish irradiated with 2,000 R, leucocytes began to increase after the 3rd day, reached a maximum on the 21st day, and decreased to a low level. Leucocytosis in the pinfish receiving 5,000 R was caused predominantly by granulocytes but in fish receiving 2,000 R granulocytes and nongranulocytes contributed equally. A temporary recovery of leucocytes on the 21st day was due primarily to nongranulocytes.