Chlorophyceae, Caulerpales

Life-histories
of
Bryopsis
(Chlorophyceae,
plumosa
Caulerpales)
from
European coasts
H. Rietema
Afd.
Biologisch Centrum,
Universiteit
Plantensystematiek,
Groningen.
SUMMARY
Zygotes
of
germlings
from
Bryopsis plumosa
which
divided
into
into
Banyuls developed directly
and
longer “dormancy” period
Naples,
new
that
produce germlings
from
could
also
developed directly
into
from
Naples
Zeeland).
and
phase,
histories
and
the
grew
of the
these
collected in
plumosa
with
zoids.
interbreed
new
with
Bryopsis
the walls
site where
material
is
plants (which
and
Congo
of the
meiosis
Zeeland
could
more
interbreed
Naples
red
On
place
in
the
filamentous
from
stain
the
for
the
basis
life-history
northern
have
a
regions
Roscoff
material
Bryopsis plumosa
that
only
Bryopsis plumosa
walls
of the
of these
of
Naples
germlings
produced germlings
characteristic
positively
germling phase.
takes
and
into
germlings
In culture
Bryopsis plants.
from
Biarritz
Some
only developed through stephanokontic
Zinc-chlor-iodide
negatively
zoids.
than those of Bryopsis
(Zeeland, Roscoff). Bryopsis plumosa
to
and
Banyuls,
stephanokontic
Bryopsis
results
the life-
Bryopsis plumosa
are
discussed.
1.
INTRODUCTION
Until
by
generally accepted
that all
fuse
plants, respectively)
Meiosis
gametophytes.
produce zygotes
considered
only
evidence,
existence
of the
Zinnecker
In
caryological
(1935)
comparing
Bryopsis plumosa
the
ever,
was
above
on
the
of
life-history
from Zeeland
biphasic
Zinnecker. In the
a
other
Bryopsis plumosa
(south-western part
(Rietema
corresponded
1969)
with the
the
that
was
of
from Roscoff with that of
of the
Netherlands),
whereas
the
life-history
monophasic life-history
heteromorphic life-history
developed
places along
investigate
plants
for
incomplete),
Bryopsis plumosa
Naples.
into
new
erect
In the present paper the life-histories of
to
In fact the
how-
of
Bryopsis plumosa
of
the
observed
a
zygote
small, creeping, filamentous germling phase that produced stephano-
kontic zoids which
some
in
for-
place preceding
gametophytes.
(though
male
immediately
present author observed that the life-history of Bryopsis from Roscoff
heteromorphic
grew into
cultural
as
type of life-history
material from
material from Zeeland
by
well
as
anisogamy.
produced by
that grow
take
to
mation of gametes in the determinate laterals of the
charac-
are
by pronounced
(in Bryopsis plumosa
to
was
Bryopsis species
and
diplontic life-history
male and female gametes
Biflagellate
new
was
monophasic
a
and female
into
it
recently
terised
the
whether there
collected in different
Acta Bot. Neerl.
19(6),
December
European
are
coasts are
interbreeding
places along
1970
Bryopsis
thalli.
Bryopsis plumosa plants
the
collected in
described. Crosses
barriers between
European
were
made
Bryopsis plumosa
coasts.
859
H.
2.
MATERIAL
Material
AND
RIETEMA
METHODS
investigated
collected from the
was
localities
following
European
on
coasts.
1968; Porto Santa Lucia; north side of
Naples (Italy); May
a.
quay;
b.
Banyuls
taining
(Pyrenees
rock
The
plants
be treated in
according
A
current
Sea
FeSG
mg
4
of
often
Thalli and
only
exposed
a
small
possible
germlings
of 8 hours “short
The
of the
with
light
AEG lux
The reactions
Congo
Congo
red
material into
will
(which
Bryopsis plumosa
as
short
soil
into
in
new
a
mm or
filled with
died after
termed
or
thalli.
glass.
In this
germlings.
1 °C temperature
5
;
brought
were
watch
10
and
room
long
more
exposed
were
trans-
culture fluid and
cc
conditions. Under short
day
3
Bryopsis
thalli
Bryopsis
numbers of
tube)
3.72 mg
NaN0
mg
cut-off determinate laterals
gametangia
were
Rietema
extract;
42.5
0;
by
culture fluid. To
a
of diatoms.
developed
16 ±
a
germlings
are
2
mature
which
cc
as
transfer into
conditions
day
fresh
medium.
“long day conditions”; photoperiods
by
white fluorescent tubes (Philips TL
The
34).
the culture tubes amounted to about 1600 lux
(as
intensity
measured
meter).
of cell
walls
of
were
few
to
added
to
the
culture
zinc-chlor-iodide
on
A few
tubes.
red. The
Congo
a
thalli
mature
investigated.
was
of this stain
drops
and
germlings
survives addition of
germlings
a
in
Vierge,
conditions”.
day
solution
of thalli and
large
in every
red and zinc-chlor-iodide
Bryopsis easily
3.
(one
of 16 hours
on
in
kept
Germlings
1 °C
emitted
was
light falling
an
obtain
to
number of the
Daily photoperiods
from
from
gametes
were
16 i
to
started
used
12H
prevent growth
to
the cell walls of the
ferred into culture tubes
were
Na 2 HP0 4 .
cultures which
unialgal
conditions.
long day
la
described
as
was
added: 25
were
mg
were
Motile male and female
to
0.269
;
experiments
axes
together by rupturing
was
con-
of the genus (Hamel 1930; Newton
obtained
were
water
MnCl 2 ; and 5 mg Ge02
it
de
details
morphological
concepts
material
0.02 mg
way
Rocher
1969;
modified Erdschreiber solution
0.278
tips
pool
Arago.
1957).
slightly
present
small
1967;
of the Laboratoire
but would be identified
taxonomic
cultures of this
of main
August
another in
one
EDTA;
The
September
aquaria
zone.
forthcoming papers),
litre of filtered North
one
France);
all differ from
the
to
Unialgal
from the
upper sublittoral
1931; Taylor
(1969).
Orientals, France);
(Basses-Pyrenees,
pools,
perpendicular
a
m.
discharged
seawater
Biarritz
c.
about 0,5
depth
were
This
reactions
investigated
microscopic
to
drops
is
staining
of
a
a
with
saturated
vital stain:
of the cell walls
by putting
some
slide.
RESULTS
3.1.
Bryopsis
Determinate laterals from
into
860
plants
from
plumosa
about 2
to
3.5
a
Naples
male and female
cm
high (figs.
plant had,
1 and
2)
and
after
two
produced
Acta Bot. Neerl.
weeks, grown
male and female
19(6), December
1970
LIFE-HISTORIES
OF
BRYOPSIS
PLUMOSA
Fig.
3.
history
Diagram
of
of
the
Bryopsis plumosa
lifefrom
Naples.
Ada Bot. Neerl.
19(6), December
1970
861
H.
Fig.
1.
Two weeks
from
Fig.
2.
Two weeks
from
Fig. 4, 5,
6.
an
old
isolated
an
plant
of
determinate
old female
plant
isolated determinate
Bryopsis plumosa, Naples
offspring
zoids
material
(grown
in
culture
(grown
in
culture
lateral).
of
Bryopsis plumosa, Naples
material
lateral).
Morphologically diverging plants
stephanokontic
862
male
RTETEMA
produced by
one
of
Bryopsis plumosa
and
the
same
grown
filamentous
in
from
culture
germling
in
the
of Naples material.
Acta Bot. Neerl.
19(6), December
1970
LIFE-HISTORIES
PLUMOSA
OF BRYOPSIS
gametes, respectively. These plants
from
plants
number of filamentous
germlings
directly
within
and
five
7 weeks
about ten
via
indirectly
of
in 30
and 3 monoecious
plants;
2 monoecious
of
Bryopsis
plants.
remained
3.2.
It
of
stephanokontic
the fact that the
Crosses
male gametes
Naples
one
is
plants
large
a
three months old
directly,
or
male,
there
one
vegetative
and
7
contained
subcultures these
monoecious
female,
13
via the
11 male,
and
male,
sex.
production
illustrate
figures
morphologically
different
of the
determine the
to
5 and 6. These
figs. 4,
within
stephanokontic
female,
germling
one
15
thirty
directly,
diagram
some
were
impossible
was
germling
were
grew
Bryopsis plants
in fig. 3. The
female,
in-
Bryopsis plants
new
medium. A
germling
it
in the
depicted
of
new
given
plants produced by
zoids is
between
germlings
diverging
morphological types
obtained.
seven
vice
about 10 months old all
material with
Thus hundreds of
versa.
produced stephano-
weeks of observation after transfer into fresh medium.
zoids
stephanokontic
germlings
Germlings
Roscoff material
produced by Naples
Roscoff material and
produced by
were
material and
Naples
fertilize female gametes
to
kontic zoids within
30
into
original
constant.
proved possible
The
of
into
into fresh
in 30 of another there
some
some
offspring
In
from
offspring
In
plants).
morphology
zoids
germlings
germling produced
one
plants (for example
The
two to
and of these four
observed,
were
stephanokontic
Bryopsis plumosa
from
zoospores
zoids,
the
produced
had grown either
stephanokontic
months old
after transfer of the
life-history
five
to
weeks after transfer into fresh medium. On the other hand
seven
germlings
of these
none
of
production
similar
female gametes
creeping germlings. Twenty
observed and
were
via the
morphologically
were
Mixtures of male and
nature.
grew into
observed either
grew
new
out
fertile
directly
Bryopsis
or
plants.
remained
None of the
permanently
in the
germling stage.
3.3.
It
Crosses
also
male
between
proved
Germlings
directly
grew
into
3.4.
Bryopsis plants. During
new
permanently
Bryopsis
Germlings
at
Banyuls
zoids,
into
zoids
in the
new
seven
grew
Acta Bot. Neerl.
from
directly
Bryopsis
out
of
December
the 7 weeks of observation
none
zoids
or
Banyuls
indirectly,
within
a
being
new
1970
derived from mateiial collected
via
seven
5 months old
of
into
were
medium, only
produced stephanokontic
(30 observed)
nor
plants
thiity
weeks
directly
19(6),
germlings
germling stage.
months old
grew neither
within
germling
two
observed
germlings
plumosa
about
medium. Seven
material. Hundreds of filamentous
about 10 months old, after transfer into fresh
of the total number of 30
remained
Zeeland material
fertilize female gametes from Zeeland material with
gametes from Naples
obtained.
material and
Naples
to
possible
production
weeks
after
of
stephanokontic
transfer
into
fresh
germlings produced stephanokontic
transferred
into
fresh
medium.
Only
one
Bryopsis plant.
863
RIETEMA
H.
3.5.
Bryopsis
directly,
months
two
via
indirectly
nor
the
Bryopsis plants during
four months
from Biarritz
plumosa
about
Germlings
(eight
germlings
of
production
seven
germlings
two
old
the
did
observed)
not
grow
zoids, into
stephanokontic
new
weeks after transfer into fresh medium. Within
grew
indirectly
out
via the
of
production
stephano-
kontic zoids.
Four
during
of twelve four months old
out
3.6.
Staining
the
germling
The
cell
reactions
walls
phase
of
walls of the
germlings
did
not
all
at
in the
thalli
Bryopsis plants
This
phenomenon
4.
period
of observation. With
thalli
Bryopsis
the
inner wall
between
crosses
in
Naples,
red.
by Congo
zinc-chlor-iodide
a
stained violet whereas
immediately
germlings directly developing
into
stained with zinc-chlor-iodide.
layers
observed in
Naples
The
localities
same
germlings
obtained from
and Zeeland material.
DISCUSSION
The first
vations
1935).
made
Bold
1957;
biphasic life-history
from
population
Naples
In
grew
zoids,
collected
at
grew
contrast to
monophasic
be realised within
Naples.
The
one
filamentous
new
Banyuls
more
less
or
via the
the
Iyengar
present obseivations
where Zinnecker
locality
and the
and
a
which
production
the
of
the
zygotes
stephano-
derived from Bryopsis
as
present
heteromorphic
Bryopsis plumosa
same
into
same
widely
was
her observations the
germlings
Bryopsis plants. Germlings
behaved
anisogametes
life-history
life-history
partly directly, partly indirectly
into
comparing
directly
As in the
to
the life-histories of
Bryopsis plumosa
Roscoff
induced
864
can
a
monophasic, diplontic
The
same
Naples
plumosa
germlings
from
material.
with that of
that
exactly
In
1966).
the
obser-
on
in
Bryopsis (Fritsch 1945;
Chadefaud
Bryopsis plumosa plants.
a
the formationof
this type of
recently
material collected in
author’s results show that both
kontic
place preceding
Until
based
was
Porto Santa Lucia
at
These observations gave evidence of
1955;
on
collected her
developed
Bryopsis plumosa
collected
characteristic for the whole genus
as
Smith
1951;
in
life-history
determinate laterals.
accepted
were
a
Bryopsis plumosa
on
in which meiosis took
life-history,
the
of
description
made
(Zinnecker
in
stained red
and
phase
red
from material collected
were
particularly clearly
was
Bryopsis
Congo
derived from material collected in the
same
only
Zeeland material and
derived
remained unstained. In
germlings
new
walls of the
and Zeeland,
solution the cell walls ot the
those of the
cell
zinc-chlor-iodide and
Roscoff,
cell
stain
of the
to
Bryopsis
Biarritz,
Banyuls,
zoids
germlings produced stephanokontic
weeks after transfer into fresh medium.
seven
germlings
into
always
Bryopsis
“break” their
Naples
and
Bryopsis plumosa
from Roscoff
divided
plants)
into
and
“dormancy”
(see
further
was
Naples
1969)
stephanokontic
than the
Banyuls germlings it
from
Rietema
could
Banyuls
not
easy
Ada
to
striking
(and
more
never
easily
be
Naples germlings.
break the
Bot. Neerl.
Banyuls
was
zoids
much
and
and
it
19(6),
“dormancy”
December
1970
LIFE-HISTORIES OF
of the
BRYOPSIS PLUMOSA
derived from
germlings
germlings
also
grew
from
plumosa populations
in their
germling stage
of
production
southern shores of
more
life-history
that is
have
These
zoids
that
suggest
Europe
of
capable
Biarritz.
stephanokontic
above-mentioned observations
All
Bryopsis plants.
new
collected in
Bryopsis plumosa
via the
indirectly
into
Bryopsis
filamentous
a
producing stephanokontic
zoids.
from Zeeland (a
Bryopsis plumosa
collected
Helgoland (Neumann
on
northern
formation of
of
also
regions
lacks
this
and the
Bryopsis plumosa (Zeeland)
filamentous
tend
“accelerate” the
to
compared
with
Successful
more
from these three
are
always
not
to
and
grew
from
out
of
obtained from
between
population
of this
of the
species
populations
as
and
Zeeland
material
motile
in
possibilities
Banyuls
between
capacity
germlings
and Roscoff
Naples
Naples
Zeeland material
zoids
stephanokontic
between
always produced stephanokontic
crosses
indicates that the
directly,
both
or
in
(the
Bryopsis plumosa populations
crosses
Roscoff and
is
of
and Zeeland
1969)
(Rietema
germlings
produce,
to
determined.
genetically
derived from Bryopsis
or
The
plumosa
however, that differences in the mode of
suggests,
of the filamentous
development
monophasic
species
stage
“dormancy”
northern
Roscoff",
Naples,
obtained from
germlings
and
Naples
a
northern
populations
more
barriers between
cultural conditions
applied
crosses
produce,
occurrence
between
germlings
material under the
material
the
of
regions.
The fact that the
zoids, while the
Zeeland
of
Bryopsis
populations.
genetic
no
this
a
this
lacks
Bryopsis hypnoides
disappearance
“break” of the
rapid
life-histories
southern
interbreeding
suggest that there
The
of Roscoff and
germling stage
that
1969a) suggest
capacity.
from
germlings
on
zoids) in the life-history of
stephanokontic
Europe)
northern shore in
more
Observations made
capacity completely.
germling phase,
biphasic life-history,
are
and hence the
of
occurrence
a
without fundamental taxonomic im-
portance.
The fundamental similarity of
germlings
identical
developing
negative
reaction
walls of the Bryopsis
parently
the
considerably
directly
to
chemical
wall
of the
terms
Bryopsis plumosa
As mentioned
the
occurrence
are
above,
19(6),
of the
wall
new
of the
of the
that did
and
Zinnecker
previous
diplontic
only
a
December
some
(1935)
to
germling phase
as
an
Ap-
differs
interesting
outer
The
that
wall-layer
inner wall-
that stained with zinc-
applied
case
to
the
life-history
premature.
produced caryological
evidence for
the formation of the gametes in the deter-
of the
grew into
stephanokontic
male
zoids
Bryopsis plants,
few into monoecious Bryopsis
1970
an
stain and
not
their
both stains.
to
had
Bryopsis phase)
by
red stain.
In this respect it is
Bryopsis plants
zoids and
confirmed
reaction
therefore incorrect and in
any
germling (Naples material)
Acta Bot. Need.
into
wall
minate laterals. The fact that
and
positive
Bryopsis phase.
monophasic
of meiosis
Bryopsis plants,
a
germling phase)
with the
chlor-iodide. The
of
Bryopsis plants
is
zinc-chlor-iodide and Congo
composition
from that of the
layer (continuous
the
new
phase always give
germlings developing directly
(the original
germlings producing stephanokontic
into
produced by
some
plants,
into
one
female
and the
fact
865
H.
that the
from
offspring
Therefore,
tories of
caryological
a
semble the
is
the
Possibly
as
in its
which
life-history (Hustede
and
proved
lifehistory
of
a
of
Bryopsis
serve
filamentous
creeping
life-his-
place previous
would
ovalis
neglecta
as
which
re-
has
as
sporophytic
a
intermediate between
an
which have in their life-histories
Bryopsis species
sporophytic phase (viz.
could
take
1969b).
has Derbesia
1964)
to
Halicystis
sporophytic phase (Neumann
a
Bryopsis halymeniae
subcul-
germling phase.
site of meiosis in the
If meiosis
heteromorphic biphasic life-history
Derbesia marina
Halicystis
the
on
diverging
vegetative
somewhere in the
place
zoids
morphologically
after further
constant
required.
stephanokontic
contain
may
reinvestigation
Bryopsis plumosa
the formation of
phase
germling
rather suggest that meiosis takes
turing)
to
one
characters of which remain
plants (the
RIETEMA
only
a
reduced
phase producing stephanokontic
zoids).
monoica and southern
Bryopsis
in
their life-histories
zoids
stephanokontic
(Rietema,
of
populations
filamentous, creeping
a
also have
Bryopsis hypnoides
which
germling phase
produces
unpublished).
ACKNOWLEDGEMENTS
The
the
author is much
of Sciences
Academy
material
indebted
Grants
manuscript.
in
Naples
“Stazione
for
the
and of the
and
“Stichting
Napels,
at
for
Hoek
discussion
commission
of
P.W. Korthalsfonds”
He
would
“Laboratoire
and
hospitality
den
van
Naples-Roscoff
Biarritz, respectively.
Zoologica”
Mer” at Biarritz
to Prof. C.
from
Arago”
facilities
working
like
in
author
directors
and
Banyuls,
at
the
reading
of
Netherlands’
Royal
enabled
to thank
their
and critical
the
to collect
and staff of the
the
“Musee
de
la
institutes.
REFERENCES
H.
Bold,
C.
(1957): Morphology of
Chadefaud,
L.
M.
(1960):
Emberger:
F.
Fritsch,
E.
Traité
Les
de
(1935/’45):
Plants.
végétaux
&
Harper
non
botanique systématique,
The
and
structure
New
Row,
vasculaires,
York.
In
cryptogamie.
Tome
1.
M.
Chadefaud
&
Paris.
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