Abstract: The micro method of hematocrit is rapidly replacing red cell counts in clinical hematology. Observations were made on the value of this method in routine hematological examination of trouts. Under the conditions of data collection, the normal hematocrit values for brook trout were 45 to 50, for brown trout 39 to 44, and for rainbow trout 45 to 53. There was a close correlation between the hematocrits, red cell counts and hemoglobin. The commercial heparinized capillaries, while excellent for human blood, tend to give somewhat higher readings (7 to 18 percent) with trout, due to incomplete prevention of blood coagulation. The procedure as applied to trout is described in detail.

Excerpt from Microhematocrit as a Tool in Fishery Research and Management The purpose of this investigation was to determine the practicability of large-scale micro hematocrit measurements in fish culture and to establish values which may serve as normal for trout until more extensive data are collected. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Adult northern puffers were exposed for periods up to 45 days to either 30 parts per billion (ppb) of the organochloride insecticide methoxychlor, 20, 200 ppb of the organophosphorous insecticide methyl parathion, or to a combination of 15 ppb of methoxychlor and 10, 100 ppb of methyl parathion. These concentrations will produce approximately 5 percent mortality in 96 hours under the conditions of the experiment. Profiles were constructed on the effects of each insecticide on blood and tissue components. The visual patterns provided by these profiles suggest a means of identifying unfavorable environmental conditions before the appearence of obvious morphological or physiological changes.