Eagle River review. [volume] (Eagle River, Wis.) 1890-1927, 1915-10-01

Several hundred kinds of deep-sea fishes mad
been collected-some of them dredged from
depth of more than a mile-and 1t required
huge quarto to describe and picture them From
this volume dates our real knowledge of the
fishes of the abyssa1 deep The Challenger
expedition was inded, Columbus voyage IN
ichthyology; it opened new chapter in the his
tory of the science.
Since that time many deepsea exploring ex-
petitions have been sent out by the various ma
tons and hosts of other fishes have been
brought up from the oceans in all parts OF the
world More than a thousand species are now
known and we appreciate at its run value
the richness and strangeness of this fauna.
Moreover not only do we know the fishes them
selves but as & result of the scientific lnvest-
cations carried on by the various expeditions.
we now know good deal of the physical con-
ditons under which they live so that we can, IN
a measure at least, explain the why and where
fore of their extraordinary characteristics
When we think of life in the dee2-sea, there
comes to mind first of all, the enormous pres
sure which these creatures must Withstand.
This pressure becomes the greater the deeper we
go down and in the profoundest depths 1t equals
thousands Of pounds to the square inch. me
result of this pressure is that the tissues OF eso
fishes are tender and loosely knitted togetner.
When they are brought up out OF the dark
depths and the great pressure under which they
live is removed the explosion or the gases WIFI
in them bulges out the eyes, and often ploWs out
the viscera through the mouth, while the mus
cles collapse leaving them soft and naDpy IKE
moist rags Most deep-sea fishes are very smau
also usually only few inches in length, and 1t
is probable that this reduction in size has come
about, to some extent at least, from the great
pressure under which they live.
Another important condition is the dimness OF
light or even darkness in the profound deptns
of the sea. If we imagine ourselves descend
ing into the deep ocean, we see the lgnt gro"
oOOd nVun
level is reached beyond which no light pene-
trates at ALL The entire vast depth below 1T, is
in eternal darkness Now the fishes living IN
this dim light, in total darkness, have been
profoundly modified by it. In some forms the
ewes have become very small, and in some cases
have entirely disappeared There are even hsnes
in which the skin and scales OF the body nave
grown over the place where the eyes should
be- so that these fishes are, as has been aptiy
said blind beyond redemption other. FORMS
on the other hand, have been anected IN an
entirely different way. The eyes. instead OF
growing smaller. have grown larger, as II In an
attempt to catch every ieeting ray of light In
some fishes this has been carried so far that the
eyes have become like enormous goggles
Most deep-sea fishes have luminous organs OF
one kind or another so that they carry their
own light about with them. In some the entire
body glimmers, the coating OF slime winch
exudes from the pores and lateral canals, emit
ting soft silvery glow. In others rows of mi
mute luminous organs run along the sides OF the
body. or there are flashing light-spots on the
head or face What wonderful sight would be
10 us a small black fish fitting through the ST.
lence and darkness of the deep with its head
lights and row of pores cleaning through the
darkness like some small ship passing through
the night with its portfolios all aglow! Some
deep-sea fishes have luminous organ at the
end of feeler on the head
pertinent question may be asked: How do
we know these fishes glow and glimmer since
no human eye has ever behed them int their
abyssal home? We know this partly from anal
ogy and partly from actual observation. When
one is in a boat in the tropics. on one OF those
sultry nights when everything is dead calm,
and the black clouds hang so low that sky and
sea form one continuous blackness, then one
may see the glmmering fishes darling out of the
path of the boat, their FORMS silvery and ghost
like. outlined for one moment against the black
ness of the sea. This effect is chiefly due to
the oxdizing of the Shiny secretion covering
their bodies Why shall we not believe, then.
that in deep-sea fishes similar phenomenon
takes place. particularly as in many of them