Sioux County pioneer. (Fort Yates, Sioux County, N.D.) 1914-1929, 1915-10-01
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the slime pores and canals are greatly developed
and must exude large quantities of slime? Then
too, on deep-sea expeditions, on favorable occa-
sions. as for instance, dark calm night, fishes
that have been brought to the surface and placed
in water were seen to flash light from the ends
of the tentacles or the phosphorescent pores,
precisely as we should have expected from
study Of these organs Major Alcock, in his
interesting volume. "a Naturalist In Indian
Seas" mentions specimen brought up from a
profound depth which "glimmered like ghost
1t lay dead at the bottom of the pail of turs
bid seawater." So that by inference, we'll as
by actual observation, we must believe that what
we call luminous organs in deep-sea fishes, emit
light into the darkness about them. In the case
of fishes totally blind. the absence of light is
compensated for by the development of enor-
nous antennaelike feelers, modified from fin
rays. so that these fishes can feel their way.
as it were through tho darkness.
The absence of light, however, entails another
important consequence AS is we'll known, no
plant life exist in darkness. There is there
fore vegetation Of any kind in the profound
depths of the sea- The deepsea fishes are, in
consequence, all carnivorous, the more powerful
ones selling and devourng the weaker ones 1t
is cold black world where might regns su-
preme. Many have enormous mouths and for
mfdable teeth to insure holding the prey. In
some forms the teeth are so large that the mouth
cannot be shut!
The temperature of the water in the profound
depths Of the sea, is always low and near the
freezing point. This is true everywhere, even
at the equator Undoubtedly this has an effect
upon the fishes although it is not yet known
what 1t is. The amount of oxygen dissolved in
the water also. is much less than in water nearer
the surface. The breathing apparatus Of the
deep-sea fishes is modified to suit their peculiar
conditions. The gill flaments have become much
reduced in size. and in number Of instances
some Of the gill arches bear no gill filaments at
mi, Ac1,oe oHo tod f0
much smaller oxygen supply than those living
in rivers or in the shallow sea.
When think of the vast diversity among
these fishes, the question arises: Are they all
representatives of single family or group that
has become specially adapted to life in the deep
sea: or do they belong to different families or
groups? One need hardly be an ichthyOlogist
to answer this question. Even cursory exam
ination of the plates in work on deep-sea
fishes will show that different types are repre-.
sented In fact. great many families are in
cuded in the deep-sea fauna. There are sharks
and rays; salmonoids, behring's, perches, eels.
and representatives of many other families. We
can explain this heterogeneity among them in
this way. We may imagine that fishes of many
different kinds in their search, to speak, for
the unoccupied corners of the sea, found haven
in these deeper waters where they free
from pursuit by their enemies In the course of
time they migrated farther and farther into the
Deep change in habits taking place pari passu
with the changes in structure. Having started
out with different organizations, and possessing
different degrees of variability. they became diff
ferentiated in diverse directions, so that while
some developed enormous mouths. powerful
teeth, or phosphorescent organs. others became
bottom-living and partly or completely lost their
eyes. Still others developed long feelers for
cropping their way through the darkness Now
and again. however, fishes Of separate groups
developed similar structures, so that there are
many striking cases among deep-sea fishes of
what the biologist calls Conveyance" or paral-
lesm
The museum has recently prepared for exhi-
btion number of typical deep-sea fishes
ranged in the form of group. The preparation
of this exhibit involved many technical Difficult.
ties. such the modelling of the fishes in trans
parent or translucent media. to represent them
as glimmering or shining With lit-up "portholes."
Considerable experimenting was necessary to