Biology Reference
In-Depth Information
Another change that occurs during metamorphosis of lampreys is the
deposition of iron in various tissues and the liver is one of these primary
sites (Fig. 15). There is a progressive deposition of iron within the cytoplasm
of hepatocytes such that by the time metamorphosis is completed and
into the immediately postmetamorphic juvenile, the livers are iron loaded
(Macey
et al
.
, 1982a; Youson
et al
.
, 1983a,1983b). For a further summary of
this topic of liver iron see Youson (1993). Further discussion of the change
in iron metabolism will appear below (
Iron Metabolism and Blood
).
Figure 15.
Light micrographs showing the staining for iron with Prussian Blue in the liver
(L) of larva (a, b), stage 5 of metamorphosis (c, d) and in a juvenile (e, f) of
P. marinus
. Note
the progressive increase of liver iron (blue stain) during metamorphosis into the iron-loaded
state of the adult and the absence of this metal in the oesophagus (O) and intestine (I). There
are bile ducts (BD) in the larva liver but none in the livers of metamorphosing animals or the
adult. (a, c, and e. X25; b, d, and f. X250).
Color image of this figure appears in the color plate section at the end of the topic.
2.8.1.7 Respiratory system
It has been referenced above that there is a different mode of ventilation
in larval and adult lampreys that is related to their different modes of
