The Washington herald., 1922-03-21
EXPLAINS LIFE HISTORY
OF DESTRUCTIVE sHIPWORMs.


OF DESTRUCTIVE sHIPwoRMs.
American shipwo=ms we're dis
cussed and exhibited by DR.. Paul
Bartsch. OF the United States Ma
tional Museum, at the meeting OF
the Biological Society Saturday
night
First OF all Or. Bartsch disproved
that they were worms at all, and
said that they were really moiluska
related to our oyster and clam
He gave an account OF the structure
~Of these snimsls and their life hts
tory. utilizing as his example
Gould's shipworm, the life history
OF which was almost completely
worked out by Prof. Sigerfoos in
1908 at the U. S. Bureau OF Fish
cries station at Beaufort, n. c.
lie stated that there are two types
Of shipworms in America. one which
gives birth to living young. while
the other type is egg laying. GoUlds
shipworm is OF the latter type. he
explained. After the eggs hatch. q
little free swimming lsrva ensues
which after leading a pelsgic exist
ence for a time, the length OF which
has not definitely been determined.
settles down on some piece OF wood
and begins digging a home for it.
self. beginning with a tiny pUncturc
just large enough TO admit the mi
croscopic organism, and then vid-
ening the burrow and deepening t
as IL increases in size. Some ship
worms grow to be four feet or even
more in length. with a diameter the
size Of your thumb. he said. After
! the burrow Is complete. the end is
sealed up with a calcarecus lining.
In fact the entire burrow has been
beautifully glazed after its eNcava-
( tion. The mollusk now stops bur
rowing. and busies itself with feed
ing and reproducing. and IL has
been stated that a single species can
give rise TO anywhere from SOC. 0OU
! TO 100000 offspring.
The food OF these animals con-
sists not OF wood. as is generally
supposed. but Of the free swimming
microscopic organisms that live In
the sea. collectively called Planktnu.
which are strained from the water
that is constantly forced through
the Gills by means Of the ella. and
by means Of ella carried to the
mouth and the digestive tract.
Shipworns are very destructive
The most conspicuous loss suffered
Francisco Bay. or moro properly
San Pablo and Suisun Bay, OF the
San Francisco Bay. where no less
than $50. .0oO. 600 worth Of destrUc-
tion was produced by Mesch's Terc-
10 in ls1s-lseo. An equal loss is
probably sustained annually along
our various coasts Or. Bartsch
called attention to the collapse or
a long wharf in the mouth OF tho
Chesapeake Bay az Smith Island
within a period Of three months af-
ter il has been erected More re-
Gently attention has been called 20
the ravaGes OF shipworms In the
canal region. where on the Atlantic
end VIC have a huge borer known
as Keynes shipworm. which freely
attacks greenheart timber. a wood
that was supposed 20 be immune,
while a closely related shipvorm az
fects the fresh waters OF the Mira
flores Lake on the opposite side.
This is the first fresh water ship
worm reported for American
waters. Zetek's shipworm is an
other destructive element OF the
Canal Zone.
Twenty eight species were listed
for American waters, and DIT.
Bartsch stated that at least Ave
additional ones are known from
fragments, but are too fragmentsry
to permit of naming at the present
time.
DR.. Bartsch gave pictures OF these
various boring mollusks, and a sim
pie key by means OF which the
groups might be distinguished He
also showed actual, specimens. and
wood drilled by them. He expressed
a hope that there might be a con-
certed effort on the part OF all
maritime nations TO pool enerEics :
10 the working out OF the life his
tories OF these pests.
He stated that there are four
distinct problems presented:
A systematic study which mus;
form the foundation for all Other
inquiries. This. he said. had been
attempted for the American spc-
cies in a monograph prepared by
him. now going through press.
A study Of the range in distriou 70
tinn Of the various species and the
relative abundance.
An examination Of the rhy..ca'
occanoEraphic conditions that de-
tcrmine this distribution.
\ study OF the life histories o.
the various forms.