Washington standard. [volume] (Olympia, Wash. Territory) 1860-1921, 1882-03-10
Crab Life.

This well-known crustacean has q
somewhat peculiar life-history 1t be-
gins its existence in decidedly abnor-
nal and unusual fashion. Instead of
breaking free from its egg-carried
about by mater Cancer in her s'purse"
III company with hundreds of its breth-
rem and sisters, likewise in the egg- state
the young or baby-crab appears on the
stage of existence as n curious little
creature with an enormous head, and a
short, jointcd and forked tail. 1t is no
more like the perfect crab than it is like
an alligator. 1t more nearly resembles
an abnormal shrimp on rowing expe-
dition than the staid, angular crusta-
cean whose progeny it is, and whose
likeness-on the idea that "like begets
like"-we shall expect it sooner or later
to assume. Its big head bears in front
two great compound eyes, and is drawn
out above and below into long pointed
spine; while two pairs of feelers and
three pairs of jaws complete the furnish
ings of this infant crab.
Behind the head come at least two
pairs of legs which will be represented
in the perfect crab as "foot-jaws," and
then succeed mere rudiments of six pairs
of appendages, of which all but the first
are represented in the adult state by the
walking legs. The jointed tail itself has
at first no belongings in the shape of
appendages or aught else, but legs be-
come mapped out at later stage on the
tail. Now when this young form was
first noted by naturalists it was regarded
rs = new species of crustacean, and was
accordingly named Zoea. Now, how
ever, we know that the Zoea shows evil
dent signs of changing into something
different from its youthful state. Its
body becomes broader, and the limbs
behind the head come to resemble those
of the ful-grown crab. Then the Jaws
are completed in their transformations,
and by and by the young crab appears
before us, crab rs to its body, but q
lobster as to its tail. For it still retains
this latter appendage, and is known in
this second part of its life history as the
Megalopa-a name signifying "big-
eyed" in reference to the large eyes it
possesses; which organs have now be-
come fixed to the end of stalk.
Like the Zoca, the Megalopa stage of
CioD-lhC was III hiSL ItSuTucu rs repre-
senting a new and before unknown ami
NAL form. Changing its skin frequent
ly. as it did in passing from the Zoea to
the g-eyed" stage, in which the crab
looks more like a lobster than the tail
less crustacean it is destined to become
the Megalopa or youthful crab begins
to assume the full-grown form. The
body becomes broader, and the tail
grows "small by degrees and beauti-
fully less" until it becomes tucked up
under the body, and exists in the ma
tured crab-eXistence as the familiar
"purse" which children are so fond of
prying into. Thus we see that crabs
body is, to put it popularity, all head and
chest. The lobster or prawn.has not
merely a head and chest (united to
form the so-called "head" Of that ami
mal), but tail or abdomen as well.
And from the fact that our crab in its
infancy possesses tail, but afterward
loses this appendage, we should be in
clined, in a geological sense, to believe
that the crabs present a higher crusta.
cean race derived from the lower lob.
sters of their kith and kin. At least, it
is certain that Holsters and their kind
were crawling over the rocks and SWIM
ming in the seas of this worlds former
epochs, ages before the crabs appeared.
This much we know from the history of
fossils. s.-ChGmberS' Journal.