There is a wealth of literature dealing with fish gills
(Review, see Hoar & Randall, 1984), yet hardly anything is known about the gills of cephalopods. This is rather
surprising considering the commercial importance of the
cephalopods.
In view of the paucity of information available it was
necessary to start by establishing the morphology of the
gills. This is covered in the first section of this thesis.
Of all the cephalopods, Octopus vulgaris was singled out
for more detailed investigation (see chapters 2 & 3) as its
physiology is comparatively well understood (Wells, 1978).
The gills of cephalopods are the major sites for respiratory
gaseous exchange. It follows that their dimensions might be
expected to govern their potential for absorbing oxygen.
Section two deals with the morphometries of cephalopod gills, and predicted values are compared with physiological
measurements of oxygen uptake for four representative
The final section describes the physiological experiments I
performed on octopuses. These experiments were designed to
find out whether the animals could regulate the gills'
potential to take up oxygen through changes to the gills
themselves
