June 12, 1981 - The Rites of the Horseshoe CrabPage 17
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The Rl'otes of e Horseshoe Crab,
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From the water's edge, the dark lumbering bodies of these crabs would be seen prodding their way in- shore;
the large female in front with the small male or perhaps two attached to her back. o
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BYPA UL 4T6kTEN.9 URGH
This past week wd've had a full moon
and at this time of`year it casts a spell of
tranquility over the area, especially along
the beaches. It's the mystical time of quiet
waters and ancient rituals. It's the
spawning time of the horseshoe crab. I
wish everyone had the .opportunity to
witness on these clear glittering moonlit
nights the ancient rites of the horseshoe
crab.
From the water's edge, the dark
lumbering bodies of these crabs would be
seen prodding their way in- shore; the
large female in front with the small male or
perhaps two attached to her back. They
move back and forth along the shore until
some old and unknown instinct tells them
this spot will do. They press deep in the
sand to lay their eggs, which the male then
fertilizes. Their only purpose is to deposit
their eggs, after which they depart for
another year.
The moon has created a super high tide
above the ordinary high tide mark. It is in
this area that the eggs later will be
warmed by the sun and will develop. The
following month the cycle of the moon
swings again and the tide once more rises
above normal. Now these thousand to ten
Paul Stoutenburgh, a former naturalist with the
Fire Island National Seashore, writes FOCUS
ON NATURE for East End weekly newspapers.
Mr. Stoutenburgh will be presenting his views
on Fire Island nature throughout the season.
thousand eggs laid by the female are fully
developed. The small crabs break out of
their enclosure to freedom, which for most
will be short lived. Only a few will ever
make it to adulthood. Nature cannot take
chances with just a few, and so
overproduction is a necessity in the sea
world. They crawl and swim and make
their way to the sea. Predators of all kinds
attack. Fish, crabs and even birds swoop
up the helpless as they scurry about
unprotected.
Once free the small horseshoe crab
feeds on a maze of microscopic organisms
that are found in our rich bays and creeks.
It grows fast and because of its rapid
growth must shed its shell. Its skeleton,
hard on the outside, cannot expand and so,
like most arthropods, it leaves behind an
empty shell.
It will go through a shedding stage many
times. When young it sheds very often,
sometimes five and six times the first year.
The better the food supply, the more it will
stied.
Often you will see the discarded light
tan shells of the horseshoe crab high and
dry along the tide line. Many will think
they have died and wonder about their
death. The way to tell a dead crab from one
that has shed is to look along the front
edge of the shell to see the slit where the
crab emerged. Once out, the shell
resembles the live crab completely, but of
course without any of its living parts. A
dead horseshoe crab is usually dark in
color and easily identifiable by its odor.
This shedding is probably the most
dangerous time for crabs They are
completely helpless, soft as your skin and
weak because of the process of shedding.
Many are eaten by predators that lurk
about. "Eat or be eaten" is the motto of
the sea. To escape this fate they will find a
hiding place beneath a clump of grass or
bury themselves in the mud. Here they
will wait for their shell to harden. First it
will become a leatherback, a stage
between hard and soft. Then in two or
three days or more it will emerge with its
new shiny hard shell ready to defend its
place in the world.
continued on page 35
YOUNG HORSESHOE CRABS - -These empty shells
found along the bay shore are signs of growing
horseshoe crabs. Each time they shed they emerge
larger.
Photos by Paul Stoutenburgh
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