The Olneyville times. (Olneyville [Providence, R.I.]) 1887-1917, 1915-10-01
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the slime pores and canals greatly developed
and must eXude large quantities of slime? Then
too. on deep-sea expeditions, favorable occa-
sons for instance, dark calm night fishes
that have been brought to the surface and placed
in water TO flash light from the ends
of the tentacles the phosphorescent pores.
precisely should have expected from
study Of these organs. Major Alcock in his
interesting volume. "A Naturalist In Indian
Seas" mentions a specimen brought up from
profound depth which "glimmered like a ghost
it lay dead at the bottom of the pail of tur-
bid seawater." SO that by Inference well
by actual observation. we must believe that what
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
nous antennaellke feelers. modified from fin
rays, so that these fishes can feel their way.
as il were. through the darkness.
The absence OF light. however. entails another
important consequence. AS is well known.
plant life can 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
seizng and devouring the weaker ones II
is a cold black world where might regns
preme Many have enormous mouths and for
midable teeth to insure holding the prey. In
some forms the teeth so large that the mouth
cannot be shut,
depths of the sea. is always low and 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 il 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 a number OF instances
some OF the gill arches bear no gill faments at
all The fishes apparently adapted 10 a
much smaller oxygen supply than those living
i'm rivers in the shallow sea.
When think OF the vast diversity among
these fishes the question arises: Are they all
representatives of a single family group that
has become specially adapted to life I'm the deep
sea or do they belong TO different families
groups? One need hardly be an ichthyologist
10 answer this question. Even cursory exam
ination OF the plates in work deepsea
fishes will show that different types are repre-
sented. In fact a great many families are in
cluded i'm the deep.sea fauna. There are sharks
and rays; salmonods,. herrings. 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 so 10 speak for
the unoccupied corners OF the sea, found a haven
i'm these deeper waters where they were free
from pursuit by their enemies In the course OF
time they migrated farther and farther into the
deep, a change IN habits taxing place pari passu
with the changes I'm structure. Having started
out with different organizations. and possessing
different degrees OF variability. they became diff
fereutiated in diverse directions. that while
developed enormous mouths. powerful
teeth. or phosphorescent organs. others became
bottomliving 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 "convergence." or paral-
lelism.
The museum has recently prepared for exhi-
bition a number OF typical deep-sea fishes ar
ranged in the form Of group. The preparation
OF this exhibit involved many technical dificu
ties such the modelling OF the fishes in trans
parent translucent media, TO represent them
as slimmering or shining with Iit-up portfolios"
Considerable experimenting was necessary to