KJELL JOHANSEN
Fig. 21. ( A ) Change in blood velocity in the pulmonary artery associated with
an air breath in Protopterus. CA, coeliac artery; and PA, pulmonary artery. From
Johansen et .al. ( 1968). ( B ) Changes in ventral aortic blood velocity related to the
phase of the interval between air breaths in Electrophorw. VA, ventral aorta; and B,
air breath. From Johansen et al. ( 1968).
going to the air-breathing organ is at its highest, and it declines steadily
later in the breathing interval. Similar experiments during hypoxic and
hyperoxic breathing showed that blood will shift toward the respiratory
organ when the 0, tension in the mouth is high (Fig. 22). This adjustment has the obvious rationale of promoting the matching process between blood and gas in the air-breathing organ.
Increased perfusion through skin and mucosal linings of the buccal
cavity has been frequently reported in air-exposed air-breathing fishes
(Johansen and Lenfant, 1967; Berg and Steen, 1965). The marine gobiid
fish, Gillichtys, displays some remarkable vascular changes when placed
in hypoxic water. Under such conditions this fish habitually visits the
Fig. 21. ( A ) Change in blood velocity in the pulmonary artery associated with
an air breath in Protopterus. CA, coeliac artery; and PA, pulmonary artery. From
Johansen et .al. ( 1968). ( B ) Changes in ventral aortic blood velocity related to the
phase of the interval between air breaths in Electrophorw. VA, ventral aorta; and B,
air breath. From Johansen et al. ( 1968).
going to the air-breathing organ is at its highest, and it declines steadily
later in the breathing interval. Similar experiments during hypoxic and
hyperoxic breathing showed that blood will shift toward the respiratory
organ when the 0, tension in the mouth is high (Fig. 22). This adjustment has the obvious rationale of promoting the matching process between blood and gas in the air-breathing organ.
Increased perfusion through skin and mucosal linings of the buccal
cavity has been frequently reported in air-exposed air-breathing fishes
(Johansen and Lenfant, 1967; Berg and Steen, 1965). The marine gobiid
fish, Gillichtys, displays some remarkable vascular changes when placed
in hypoxic water. Under such conditions this fish habitually visits the