Shepherdstown register. [volume] (Shepherdstown, Va. [W. Va.]) 1849-1955, 1912-04-11
Interesting Facts About Eels.

Until recently the breeding habits Of
the eel have been an impenetrable mys-
terry, as much to the naturalist as to the
angler. Neither spawn nor infant eels
are ever found in the streams in which
the adult fish abound. This fact led the
ancients to believe that eels are generated
spontaneously from mud; among fisher
men, the superstition still prevails that
they are the males OF catfish. But the
mystery, says the Geological Society
Bulletin, is mystery no longer.
The first step toward solving the prob
lem was taken when DR.. Theodore Gill
suggested that the ribbon-lke saltwater
fish known as the leptoceDhalus was the
larva Of the conger- r-eel-a supposition
that has since been proved to be correct.
Later discoveries by Delage, Schmidt and
other investigators have made the whole
remarkable process clear.
The freSh-water eel must return TO the
ocean in order TO produce its young.
But the spawn can be hatched only at
depth of about three thousand feet in
water with temperature of forty-four or
forty-five degrees Fahrenheit. Thus the
number of possible breeding spots is
limited.
The eels that live in the waters OF
northern Europe breed in the Atlantic
Ocean just southwest of the Farce Islands;
those that live in southern Europe breed
in the Mediterranean those inhabiting
the waters of the Mississippi system have
to migrate through the Gulf of Mexico TO
a point eastward and northward OF the
Bermudas before the proper depth and
temperature are found.
1t is strange that species capable OF
standing such extremes OF temperature
and pressure, and distributed so generally
from the tropics to the arctic circle, should
be so inadaptive in its breeding habits.
After Matching, the young gradually
rise to the surface as leptocephali They
have a greatly flattened, ribbon-like form,
and are completely colorless except in
the iris of the eye. They are repelled by
light; during the day they remain at a
depth of about three hundred feet, and
rise to the surface only at night.
After reaching the length OF three inch
es, the leptocephalus is gradually trans
formed into the "elver," which is typi-
cally eel-like in form. When the change
is complete the young elvers make their
way shoreward and ascend the streams
into fresh water.
The migration of the adult eelS to the
breeding grounds and the rise OF the
young to the surface of the ocean must
both be slowly accomplished, for the dill
ference between the pressure at the sur
face and that depth of three thousand
feet is very great. Fish brought up sud-
denly from this depth die at once. Doc
tor Peterson has discovered through ex-
perimentS with marked fish that the rate
of migration for the adult eel is about
eight miles day.
Eels, it will be noticed, reverse the
practise of the salmon, shad and other
fishes that live in the ocean but ascend
into fresh water in order to breed. Their
peculiar habits make it impossible to raise
them artificially or establish them in parts
of the world where the special conditions
needed for their breeding grounds do not
exist. Every effort to establish eels on
the Pacific coast Of America, for instance,
has failed.