Hypoxia-inducible haemoglobins of Daphnia pulex and their role in the response to acute and chronic temperature increase

► Quantity and quality of Daphnia pulex haemoglobin change with abiotic conditions. ► Hypoxia causes differential expression of 11 hemoglobin isoforms. ► Hemoglobin isoforms can be classified as either constitutive or HIF-responsive. ► Acute heat stress evokes similar changes as hypoxia, affecting HIF-responsive Hbs. ► Temperature-acclimation increases constitutive Hbs showing return to homeostasis.