When placed in well aerated water, Daphnia can lose haemoglobin from its blood by two methods. The haemoglobin may be passed into the eggs or it may be broken down in the fat-cells. When populations of D. curvirostris or D. pulex, with much haemoglobin in the blood, are placed in conditions in which they can produce very few eggs and are then placed in well aerated water, haemoglobin appears as globules in the fat-cells. This appears to be an emergency measure to remove haemoglobin from the blood until the fat-cells can break it down. When equally red animals, producing ten eggs each, are placed in well aerated water, globules of haemoglobin do not appear in the fat-cells. Sufficient haemoglobin is drained from the blood into the eggs to render the formation of haemoglobin globules in the fat-cells unnecessary.
- Copyright © 1955 by the Company of Biologists Ltd.