Copepods
in
Sunda
Strait
BY
H.C. Delsman
collected the
After having
in Treubia
reported
from
a
oceanic
more
istic
first
with
Sea
the
Indian
deep
transition from the
in
then,
the
transition
is
months
increases
from 50
all
fore,
the hauls
the
possible
length
m,
In the
SW
and
and
In the
From
this
from the
in his
follows
Java Sea
paper
There is
on
an
the
H.
delingen
P.
Magn.
1927,
en
in
which
rate
coast
the
of
is
whole
through
The
in
than
not
depth
the
is
width of the mouth
read
we
also
by
a
of
as
lower
Java
the
Sea,
Java
Batavia.
current
a
is
the
of Sumatra
constant
by
VAN
in:
runs
constantly
BERLAGE
by
WEEL
2
spreading
).
over
Treubia XVII,
and
its
west-
Sunda Strait."
confirmed
salinity
Sea
to
the
Mile per hour.
through
runs
:
current
the SE-coast
0.5
year round
Observatorium,
there-
was
weakened towards
is
place
along
in
This
Sea
Java
but
plankton
convenience,
this way.
year:
Sea)
runs
the
Ocean
hauls with the
the
more
water
Investigations
Indian
—>
sake of
first
Sunda Strait,
Monsoon-currents
Meteor.
east
and current-observations
Java-Sea
year,
April-May,
3.
the
Java
of
chart.
greater because then the
of
of
next
(dry)
Archipelago
Java
in
Java
degrees
accompanying
Sea
in
choose
to
and the
foregoing
nr.
the
SW
velocity
that
outflow of
BERLAGE,
Kon.
this
salinity-
1) Preliminary Plankton
2)
the
at
outward
the
as
gauze
(seil,
the north
along
stations
several
towards the
Strait
the
make
to
character-
latter. The
months
of vertical
making
offer all
monsoon
from the
seen
the East-Indian
stream
the
have been made in
used
Bangka-Strait,
from
Sunda
it
was
west
surface. For
Swiss plankton
east-monsoon
stream
at
as
net
in
I have
samples
the shallow
connects
that of the
to
out
the
interesting
me
might
the direction Java
to the
Guide for
strengthened
starting
in
Sunda Strait
same
4 m,
Sailor's
through
ward
in
diurnal tidal
"This
NE
depth
be
may
allow the
to
before
year
insufficient. The
1 1/3
visited
(wet)
to
to
it
as
Sunda Strait
the
try
therefore,
former
in
between
considerably
meters
and,
of the
cruise
a
sufficient
everywhere
net
made
The stations
monsoon.
depth
I
1933,
to
similar
be able
to
find
which
on
gather
to
in order
seas,
for this purpose,
Ocean
plankton
Java Sea
It seemed
regions.
two
Sunda Strait
place
Indian
collections and
two
differences between the
the
in
the
the
thought it desirable
of the East
area
between
comparison
a
plankton samples in
1939, I
XVII,
Entrances.
the
1939Verhan-
Suma
tra
Java
Sea
Java
Numbers
also
the
of
copepods bigger than
numbers
of
2
mm
Undinula vulgaris
cross
lines
�
caught
+
�
through
during
and
the
U.
my
cruise
in
Sunda
vulgaris copepodid
stations
indicates
Strait
V
(>
copepods
in
April-May,
2
mm).
per
m³.
In
this
1933.
map
Indicated
1
mm.
of
are
the
COPEPODS
and
water
ocean
found in the
are
in
SUNDA
mixing with it,
gradually
increases
gradually
IN
the direction
of
middle part
of
so
i,
129
that in Sunda Strait the
Indian
the
diagram
STRAIT
the
The
Ocean.
stations
Java Sea
salinity
latter stations
at
both
the
extremities.
The salinities
that the
the
salinity
that
no
at
50
A few
may
Java
and
increase
no
surface
the
may
from
in
the
very
Java
considerably.
mixes
the
surface
Copepod
and
the
five
I
found in
Sunda
approaches
the
ocean
nearer
to
m.
50
with
length
a
one
2
mm
surpass
or
five.
Labidocera species,
two
or
of
number.
common
the
saw
species
Strait,
all with
a
number of
of the
Java
species
Sea
(Un-
Candacia bradyi and
length of
2
mm
or
more
:
Labidocera detruncata
Undinula darwini
Eucalanus
depth
slower than
earlier with
dinula vulgaris, Eucalanus subcrassus, Euchaeta concinna,
Labidocera acuta)
further
surface and
quantity doesnot
Sea into Sunda Strait 1
Besides
at
species
considerable
restricted
see
it.
Pontella securifer and
e.g.
or
in any
at
we
rises much
salinity
water
i
part of Sunda Strait
of
mixing
5-8, the surface salinity
number of
occur
diagram
narrowest
intensive
the
doubt,
Salinities
I.
the
species,
singly
occur
Passing
Sea
which
more
ocean
lower. In
12, in the
an
without, however, attaining
50 m,
In the
cause
between stations
Fig.
more
station
at
where,
m
invariably
are
doubt
direction of the
Finally,
at
small
currents
In the
water.
the surface
difference is
where tidal
water.
at
minuta
crassus
„
attenuatus
kröyeri
„
„
Pontella
mucronatus
„
Rhincalanus
Neocalanus
Pontella
cornutus
gracilis
Candacia
„
aethiopica
„
pachydactyla
„
curta
„
,t
longimana
„
„
„
Bijdragen
tot
de
Dierkunde,
ar mata
strenua
villosa
Pleuromamma abdominalis
truncata
„
securifer
„
Pont ell opsis
wolfendeni
„
princeps
denticauda
„
Euchaeta marina
fera
Afl.
28.
xiphias
indica
gracilis
9
H.
130
Euchirella
DELSMAN
C.
venusta
Scolecithrix
pulchra
Cory caeus
spp.
„
Undeuchaeta
bispinosu
Copilia
danae
sp.
minor
„
It is
at
time in
but
entrances,
there. We
the
the
at
get
Sea
Java
rate
any
the
it
bigger species
being
especially
too,
is
the
western
Java
in
or
the
common
not
are
eastern
Sea resembles he North Sea in that
than in
poorer
absent
found
above species may be
near
fairly evident that they
seems
plankton
of the
some
that the
impression
of the
composition
several
of course, that
impossible,
not
some
the
shallow
this
adjacent
sea
with
oceanic waters,
its
low
relatively
salinity.
FARRAN
into
divided the
Four of the
forms
five
which
The
Pontella
from
forms,
a
be
to
than that of
the
be
siderable additions
having
I
coastal
a
that of
the
the
seems
the
that
plankton
pods.
5 and
stations
12
copepods
to
are
also,
in
the
again
Much
during
and
lower
smaller
are
tidal
Sea
fera)
2
at
If
we
receive
plankton,
entrance
currents
length.
mm
it shows
of
con-
evidently
which
than
which
at
have
They
big copepods
Sunda Strait
entrance of the
Java
constituted the
deficiency
shows
we
see
Strait,
compare
at
of
can
likely
bulk
big
of
cope-
stations
their maxima
constrictions.
the
number of
and attain
values
Sea.
Indian Ocean
found
are
This
here. More
plankton hauls between
station 9.
for the
through
the
way
in all the
results
decrease of
strong
a
prevail
for the
some
The
Sunda Strait.
echinopluteis
western
the values
longer
be poorer in species
to
in
curve
found in
hauls in the
also
sea
are
fairly complete,
doubt will
no
Java
seems
A look
number,
way westward
the
which
than
more
present
where the
the way home.
not
his open
considerably
is
the latter may be
The
reason
narrow
of
1
the
to
Pontella
After the maximum attained at station 3 the number of big
es
is
forms.
greater part
species
sea
open
paper.
the
our
ever
coastal
bradyi
Pleuromamma
(.~
abdominalis, xiphias,
whereas
of
and
than I
the
his
to
waters.
strong
are
of
this
responsible
a
few
collecting.
this
in
increase towards
higher
for
big numbers
here,
Continuing
here
the
for
sea
species
water
Candacia
among the open
former list
copepods
copepods
to
the
oceanic
echinopluteis
These
13 and
at
of
reef.
Labidocera detruncata,
a
list
future
added
be attributed
hardly
it
from
surrounding
number
of
character,
shown in the chart
the
belong
and
forms,
said
counted the
have
the
too
coastal
deep
forms.
sea
paper
the
cannot
same
Sunda Strait
be coastal and
to
deep
FARRAN'S
In
counted
securifer
the
mentioned above belong
inside
( Candacia aethiopica,
reckoned by him
gracilis)
found
are
and
sea
open
bigger Java Sea species
copepods
few
the
the coastal,
generally
mentioned, and
from the Barrier Reef Expedition
planktonic copepods
three groups, viz.
do
not
the stations
station
7
copepods
give high
more to
with 5,
values
the
8 with 4,
decreas-
anymore.
north, visited
9 with
3
and
COPEPODS
2,
and
at
10
io
with
then
i,
and also
of
Among the copepods
role,
and
as
was
9)
alK
of
2
ly
due
of
a
the
'
mm,
of adolescent
i.e.
the
further increase of
might draw
we
At
period.
small
9,
draw
to
situated
are
and
the
P
near
05-maxima
(which
siderable
quantity.
oceanic
1-3 and
nrs.
exact
(incl.
the
same
is
the
way as,
Atlantic
The
Sea
the
Java
are
represented
so
expected.
At
decreasing after
8,
7 and
Both
respect.
station 9,
the
that here
the
culmination
a
numbers
the
too
are
stations
maxima,
Java
from which
and
3
with
is
these
at
in
this
At
paper).
stations
that
other
species
species
it
2
greater
mm or
the
western,
10
at
Undinula
it.
than
does
con-
any
find
we
role
more
lies between 5 and
at
10
play
of
a
the oceanic
'in
found
longer
no
the
at
not
more
surpass 5
at
the middle stations,
oceanic, stations,
nrs.
The
4-7.
:
the
species
we
see
five
belong
in
stations
outer
( Undinula,
Sunda
(cited
Strait
the
Java
Sea
Sea
larger species
which
the
the
the
Java Sea
We see,
to
then,
stations
increase
in the
through
the Channel
which
are
characteristic
Euchaeta,
Indian
an
the Indian Ocean,
appear
five
Eucalanus,
and
middle,
times).
2
North
from the
to
in
again
southern
several
genera
are
wings
going
from the
going
Ocean,
North Sea.
6,
main-
are
The number
vulgaris without, however, superseding
and above
on
number of
V.
is the case,
reverse
here
5,
4,
vulgaris
ij-14),
oceanic
11)
are
dealt
not
especially
U.
(nrs.
were
station
are
The number of
8-10,
figures
In this list
in
It
stations
latter stations
they
at
be
may
too
11, the
at
stations
Undinula
accompanying
stations.
eastern
the
Ocean
stations 3 and 9
at
copepodid-stage
as
(cf
length
a
the border of the continental flat, oceanward of the diatom-
2
the
12, and also
conclusion in this
any
well
the number of adults
Indian
however,
At
The maxima
as
important
an
number of adult
latter have reached
the
as
decrease
a
lower.
vulgaris plays
former, especially
the
the conclusion that
stations,
darwini
that of
13 and
14,
adults
far
9, and
at
considerably
The chart shows the
as
V.
copepodid-stage
the latter
surpasses
Sea stations
Sea.
131
maximum
are
Undinula
more
Undinula,
vulgaris,
STRAIT
the numbers
and
Java
SUNDA
corresponding
a
2 mm
in the
case
Undinula
to
find
we
8 and 7, but all
at
IN
the
in
the
big copepods
Candacia,
Ocean by
absent
to
one
of
Labidocera)
or,
as
a
rule,
COPEPODS
DELSMAN,
132
sometimes
species
more
E.
crassus,
E. marina and
and
nuta
that
those of the
replacing,
siderably
A
we
two
Tn
are
less
we
but
in
of the
of
the
higher numbers
In
how
transition
vations.
Strait
far
curve
are
the
With
this
to
reserve
a
detruncata,
mi-
Labidocera
e.g.
the
is
bigger species,
is
con-
same
gave,
year
as
consequence
a
for
found in
October
the Java
with the
Sea:
a
April diagram
certain likeness of
numbers than in October.
higher
between
the
not
northern
maxima
monsoons
exactly
as
entrance.
at
well
the
as
At
found in
are
towards the
the
and
stations,
same
narrow-
stations
Sea
Java
again.
in other
be
the
for
curves
L.
as
general impression, however,
towards the Indian Ocean
found
species,
regards
of the
Strait, though
Strait, viz.
periods
seems
much
April
The
as
diagram
we
transition months
both the
part
least
these
ocean.
the
compare
aethiopica, pachydactyla,
C.
results.
complete
middle part of Sunda
tapering
at
the
reminded of what
curves
of
some
cruise made in October
weather,
If, however,
then
Java Sea,
the
bradyi
Euchaeta concinna
beside
and beside Labidocera acuta
found
than that of
poorer
similar
have
darwini appear, beside Eucalanus
mucronatus,
Java Sea, though rarely.
fauna of
the
of bad
I
and
beside Candacia
longimana,
kröyeri.
also in the
kröyeri,
est
STRAIT
sometimes
U.
see
we
attenuatus
wolfendeni,
and
truncata
curta,
a
and
accompanying,
Thus, beside Undinula vulgaris
subcrassus
the
SUNDA
Sea.
Java
the
IN
we
fairly
be
1933 may
years
only
may
the
venture
favourable
considered
be
ground
the
obser-
by continued
conclusion that the
feeding
for
characteristic
as
determined
middle of Sunda
especially
for
pelagic
fishes.
For
we
the sake of
observed
closely.
ficient
station
Whales
are
planktonic
where
curiosity
small
a
the
it
shoal of
rare
food.
in
Is
highest
may
big
be
mentioned here that
whales
Indian waters,
it
merely
values
for
which
were
probably they
by chance that
the bigger
near
the
approached
do
we
copepods
not
met
were
by
station 3
us
very
find there sufthem
near
found?
the