The evening times. [volume] (Washington, D.C.) 1895-1902, 1900-11-03
TILE Tiny OYSTER CRAB
A Delicate Parasite of the Popular
Shell Fish.
known to NaturnIIsts From the Earl
lest Periods OF History-TheOries
Concerning an Understanding Be
tween the BIyaiye and Its Little
Ledger - Pigmy of Crustaeeans.

The little crab. which we know rs the
oyster crab. is about the size and shape
Of pea, resembling somewhat bleached-
out spider. In Europe it is called the pea
crab. where it is rarely seen except by
naturalists. for there it is not eaten By
those who like oysters, while in this coun-
try 1t is well known, as we often see it
floating upon the surface OF p oyster
stew. 1t is common on our coast, not only
in oysters, but also in mussels and seal
ops.
The name Washington crab has been
suggested by some for the oyster crab, as
it was considered great delicacy by cur
first President
The crab has been known to naturalists
from the earliest times of history, and
the lively Imagination of writer's on Iatu-
raj history has woven curious network
of stories about the life and home OF this
modest little animal.
Aristotle. the Greek, and Pliny, the
Roman, naturalists, believed that def
mite relation of understanding existed be
tween the shellfish and its little lodger,
and even went SO far as to say that death
would be the result If the crab should de-
sert it's host. The watchful crab, living
within the home of the dull and stupid
oyster on seeing small fish approach.
would wait until one more bold than the
rest of his companions ventured within
the open shells, then gently nipping the
oyster, the doors would be closed and the
fish held q prisoner. Thereupou the two,
the host and his guest would feed at
leisure upon the body of the yenturesome
fish
very beautiful arrangement between
these two-the blind and the iame-and
q very pretty compact; but the cold eye
OF science saw that bivalyes do not feed
upon fish. but upon microscopic animals
and plants. which live and float In the
water, and that the little crab. whose
limbs are SO soft and yielding. could have
neither the strength nor the power TO
pinch off morsels of food from an CTdl-
nary fish.
The oyster crab. it is true, may act in
such manner that il warns the oyster OF
the approach OF danger, but We scarcely
believe that il is anything but a personal
motive on its part We nineteenth cen
fury folk do not believe that any iutelli-
gent understanding exists between the TWO.
We have all seen how 2 crab will hurry
back and forth on the approach OF dan
ger will dart into the first ereviee TO e.
,.
ish its formidable claws with the greatest
show of bravery. So the little Pinnotbe-
res may, with the same instinct. run back
and forth within the sensitive maatle Of
the oyster. and, retreating. push against
its soft body. which will indicate 10 the
slothfuI intelligence OF its host
that something is wrong outside,
when If will discreetly close its shell. as
the better part Of valor.
The oyster crab is about the size OF
large pea the body is globuiar, the legs
small and weak and it differs from nearly
every other crab in having perfectly
soft yielding skin In fact it was always
a soft shelled crab.
The Piunotheres are found all over the
world wherever we find oysters. mussels
or scalIoUs, from the Antarctic Ocean to
the frozen North: but IL seems that they
are only used as q table delicecy by the
American people. In the West Indies
there is an oyster which attaches itself to
the long roots Of the mangrove trees. When
Columbus first saw them he was greatly
astocfshed 10 find. among the wonders of
the Western world, oyster bearing trees,
and having read that pearls formed in oy-
sters by drops OF dew falling into their OPP
en- mouths. reported to the credulous Eu-
ropeans that the rnangroye oyster must
yield an abundant haryess, for the dew was
so heavy in these tropical islands. Dr..
that the oyster crab is very common in
the mangrove oyster. and such as eat
them do not think them bit worse for
being accompanied with some OF those
crabs. which they swallow with the (shell)
fish"
These crabs are quite common in the
true pearl oyster of the Indian and Pacific |
Oceans, and there is a specimen Of one |
of these shells in which a male is impris |
oned in the substance of the shell and COW |
cred over with a layer of mother pearl. |
The little fellow probably entered the oys- |
ter in search of his mate. and not finding |
her, wandered about and finally passed be- |
tween the mantle Of the oyster and the |
shell. where he was finally enshrouded in |
mother of-peari.
There are about twenty-seven kinds of |
crabs belonging to the oyster crab family, |
all more or less related. All of them are I
small and of a retiring disposition Some |
DO not live within the shells of a protect |
ing bivalve but remain on the sea bottom |
IndeT stones and hidden within small holes
Naturaltsts can, by the study of these |
animals, trace the different steps from the
free crab. hiding in holes and crevices, to
those which enter the open mouths of |
oysters, where, being protected from the |
attacks of enemies and having its food
brought to it by the exertion of its host,
It spends it entire life.
But perhaps the most curious habit |
found in any crab is that of a near reIa-
ton of the oyster crab which we may call |
The coral crab. This very small animal |
after the free zoea life common to most |
crabs, settles down in the fork of a grow
ng coral and waits for a home to be built |
Up around it. AS the coral grows the |
,rab is slowly surrounded by the hard |
skeleton Of the polyps. A very wonderful |
equilibrium is now formed. The crab |
must grow just as fast and no faster than |
he coral, for if ii did not keep pace with |
he coral it would be soon walled in and |
10 room allowed for its future growth |
So, until the crab has reached its full /
size, about a quarter of an inch, 1t lies |
n cup-shaped hollow, with its opening |
IN a level with the coral poiyps. When |
he full growth of the crab has been at
aimed the coral polyps would now GER
.ainly close in over the little crab and |
make it a prisoner, as did the pearl oys-
er, but the currents of water made by
he crab in breathing force the polyps to
grow slanting from the mouth of her |
ave, so that in time long, funnel shaped |
opening leads past the growing polyps to
he body of the little crab
We have here beautiful adaptation. |
The crab chooses its own-place among the |
coral branches. and then gently forces the
workmen TO build it a safe and comtforta-
Die home.-Scientifc American.
Many Cadets Dismissed.
CULVER, Ind. Nov S.-one hundred and
i've cadets were dismissed from Culver |