Bulletin of the College of Science, University of the Ryukyus

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【琉球大学理学部紀要】
【Bulletin of the College of Science, University of the Ryukyus】
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Author(s)
Citation
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Zonation of Intertidal Organisms and Community Structure of
Small Animals Associated with Patches of the Mussel Mytilus
edulis L. along the Rocky Coast of Dinard, Brittany, France
Tsuchiya, Makoto; Retiere, Christian
琉球大学理学部紀要 = Bulletin of the College of Science.
University of the Ryukyus(54): 47-81
1992-10
http://ir.lib.u-ryukyu.ac.jp/handle/123456789/13169
Bull. Coll. Sci., Univ. Ryukyus,
No. 54: 47-81 (1992)
47
Zonation of Intertidal Organisms and Community Structure of Small
Animals Associated with Patches of the Mussel Mytilus edulis L.
along the Rocky Coast of Dinard, Brittany, France
Makoto Tsuchiya* and Christian RetiBre
Laboratoire Maritime de Dinard, Museum National dUistoire Naturelle, 17 Avenue George V, 35800
Dinard, France
Abstract
A marked zonation pattern was recognized on the rocky intertidal along the coast
of Dinard, Brittany, France.
Patella spp., Gibbula spp. and balanoid barnacles showed a
habitat segregation in terms of vertical distribution.
The community structure of small
animals associated with various sized patches of Mytilus edulis ("Mytilus islands")
was
analyzed at two tidal levels and differences in the species composition were found.
At
both levels, the species richness and number of individuals increased with patch size,
but the species density (number of species/patch area) decreased.
the absolute density (number of individuals/patch area)
On the other hand,
was relatively constant irre
spective of patch size. This was due to the great abundance of small barnacles such as
Chthamalus monlagui, Balanus balanoides and Elminius modestus, which were attached to
the Mytilus shells, and the small bivalve Lasaea rubra.
show any trend with patch size, but equitability
(J')
Species diversity
decreased.
(H')
did not
The importance of
micro spatial characteristics in discussion of species diversity is emphasized.
Introduction
It is well known that very large tides, about 13 m in amplitude during
occur in the Gulf of Saint-Malo, Brittany, France.
spring
tides,
Although a great number of ecological
works on the distribution and community structure of rocky intertidal organisms have been
conducted along the coast of Great Britain
(see a review by Lewis, 1964), it is surprising
that not much comparable information is available for the French coast.
Crisp and South
ward (1958) reported the distribution of intertidal organisms along the coasts of the
English Channel, including the French side, and Richoux (1967) reported the distributional
pattern of crevice fauna
littorinids
has
also
been
with reference to the tidal level. The distributional pattern of
studied
(Daguzon,
1976).
Numerous
studies
concern
the
distribution and the zonation of intertidal species along the French coasts of La Manche
(Audouin & Milne-Edwards, 1892; Beauchamp, 1914; Fischer-Piette, 1932, 1934,
1936;
Fischer-Piette & Gaillard, 1956; Davy de Virville, 1940; Crisp & Fischer-Piette, 1959;
Plessis, 1961; Gaillard, 1965; Ancellin et al., 1969) and more precisely of Le Golfe de
Saint-Malo (Vaillant, 1870; Beauchamp & Lami, 1921; Beauchamp, 1923; Fisher-Piette,
1926, 1928; Hamel, 1928; Hamel & Lami, 1930; Joubin, 1929; Hatton, 1938).
Crevice
fauna was also described (Retiere & Richoux, 1973). Nevertheless, current information
on
the
zonation
pattern and community structure
of
intertidal
organisms
is
generally
lacking.
The senior author had an opportunity to visit rocky shores in Brittany as an exchange
Accepted : August 4,
1992.
•Permanent address: Department of Biology, University of the Ryukyus, Nishihara, Okinawa 903-01,
Japan
48
Makoto TSUCHIYA • Christian RETIERE
researcher in a cooperative research project between the Japan Society for the Promotion
of Science
(JSPS)
and the Centre National de la Recherche Scientifique
(CNRS)
in
1988 and to study two aspects of their intertidal ecology, i.e. 1) to describe the zonation
pattern of rocky intertidal
organisms, mainly around Dinard,
and
2)
to
analyze
the
community structure of small animals associated with patches of the mussel Mylilus edulis.
M. edulis has been the subject of various biological investigations (see Bayne, 1976).
It
has been known that mussel beds harbour a variety of small animals (Hewatt, 1935), but
no attention has been paid to the mussel bed community (Seed, 1976).
bed communities have been subjects of several workers
Recently, mussel
(Bellan-Santini, 1963; Suchanek,
1979, 1985; Tsuchiya & Nishihira, 1985, 1986; Tsuchiya et al., 1989b; Tsuchiya & Bellan-
Santini, 1989).
The structure of the mussel community (mussels plus associated animals),
which is designated as "Mytilus island" (Tsuchiya & Nishihira, 1985), has not been well
studied and studies on the dynamic processes within the community are completely lacking.
Because mussel beds develop all over the world, comparative studies on this community
should be useful for discussions not only of intertidal community ecology but also commu
nity ecology in general.
Secondary space created by animals or plants plays an important role in increasing
species diversity by supporting environmental heterogeneity.
In
this
sense,
the
mussel
bed system is a good model for the analysis of community organization processes because
Mytilus is easy to handle and the degree of heterogeneity can be manipulated.
Communities
developing on algal growths have been investigated (Prenant, 1923; Benard, 1960; L'Hardy,
1962; Herberts, 1964; Haage & Jansson,
1983).
1970;
Hazlett
&
Seed,
1976;
Gunnill,
1982,
Although we found interesting subjects of the communities on the rocky shore of
Dinard, we had not enough time to study them.
In the present study, therefore, discussion
is focussed mainly on the zonation pattern of rocky intertidal organisms and structure of
mussel bed communities.
Study area and Methods
Nine stations (Sts. 1 — 9) were selected for a study of the vertical distribution of in
tertidal shore organisms along the rocky coast of Dinard, Brittany, France (Fig. 1).
survey was conducted from the middle of July to late August, 1988.
The
In order to determine
the effect of shore elevation, expressed as the vertical distance from
mean low water of
spring tides (M.L.W.S.), on the vertical distribution pattern of the intertidal organisms,
the density of macrobenthic animals and algal cover within 25 cm x 25 cm or 10 cm x
10 cm quadrats was surveyed along a transect line placed perpendicularly to the shore
line at each station. The smaller quadrat was used only for counting the small barnacles
such as Chthamalus spp. Balanus balanoides*
and Elminius modestus.
The survey was
conducted at intervals of several meters, and the quadrats were placed on both sides of
each study point along the transect line.
Sea level was recorded several times at each
station during the study period and then M.L.W.S. was determined with reference to a
tide table.
At Sts. 2 and 4, many patches or dense beds of Mytilus edulis were found. At St. 4,
'Newman & Ross (1976)
proposed a new taxonomic system for the balanomorph barnacles.
separated Balanus balanoides from other Balanus species and placed in the genus Semibaianus.
They
Zonation and Mytilus Islands on Rocky Intertidal of Dinard
A^
49
Sti
Laboratoire
Maritime de Dinard
Primel-Tregastel
/
I
_A „ ,
StMalo
Fig. 1.
Map of study site.
60 patches of various sizes, 30 from around mean tide level (M.T.L.) and 30 lower ones
from 5m above M.L.W.S., were measured for length, width and height and then scraped
off fully with a spatula during the daytime low tide.
The size of mussels was recorded
and the associated animals were identified and counted in each patch.
The size of the
crab Carcinus maenas, which occurred in many patches, and the amount
each patch were also measured.
of
sediment
in
The rock surfaces from which the patches of mussels
had been removed were surveyed again about one month later and any newly invading
animals were counted.
Qualitative observations on the intertidal organisms were also made at several other
places in Brittany, including Roscoff, Primel-Tregastel, Saint-Malo, Saint-Lunaire
(La
Garde Guerin), Carnac and Vannes (Fig. 1).
Results
1. Tide and temperature conditions
According to the tide tables of 1988, a
maximum of about 13 m tidal amplitude was
shown in March, August and September, while the tidal amplitude was lower in May,
June, December and January.
A marked semi-diurnal tide was recognized.
During the
study period (July 11 —Aug.30,1988), a minimum tidal amplitude of 4.5 m was recorded on
July 24 and it increased rapidly to 12 m on August 1.
The range between the
twice
daily high and low waters decreases on passing from spring to neap tides.
Water and air temperatures, which have been measured in every Monday morning by
staffs in the "Laboratoire Maritime de Dinard", fluctuate 7 — 18*0 and 3 — 19*C, respec-
Makoto TsucHIYA * Christian Retiere
50
tively (Unpublished data).
2. Vertical distribution of intertidal organisms
St. 1
(Fig. 2): This station, with a lower intertidal boulder shore, was situated on a
relatively exposed shore at Saint-Enogat.
Among the 9 stations surveyed, this was the
only one with an entirely rocky intertidal zone from the littoral fringe to around extreme
low water of spring tides (E.L.W.S.); sandy bottoms were present around the low water
mark
at the other stations.
CZZ]
0
50 100 °/o cover
0
16
50
100 Na/0.125m2
* 0 100 200 No./100cm2
K
MHWS.-
~
10
E
-
MIL-
M.LWS-
0
Fig. 2.
Vertical distribution of rock}' intertidal organisms at St. 1.
The coverage of the yellow lichen Xanlhoria parielina was not
patchy distribution about 15 m above M.L.W.S.
Light green
high and it
had a
Enteromorpha sp. and
the
black lichen Verrucaria maura occurred above the mean high water of spring tide (M.H.W.
S.). The zonation pattern of seaweeds was remarkable,
canaliculata,
Lichina
pygtnaea,
Fucus
spiralis,
Laurencia
i.e. Enteromorpha sp., Pelvetia
sp.,
Fucus
vesiculosus,
Fucus
serratus, Sargassum muticum and Laminaria saccharina were seen sequentially from the
high to low intertidal.
species of
Around the low tide mark, other algae such as Codium, a second
Enteromorpha,
and
Himanlhalia
elongata were
also
seen.
The
brown
alga
S. muticum was growing abundantly below M.L.W.S. on a sandy bottom with many boulders.
L. saccharina was also seen there.
Large rock pools at the
low tide level were occupied
by S. muticum. Hydrozoans were common on the lower intertidal algae.
In narrow crevices around M.H.W.S., and nowhere else, small numbers of the periwinkle
Melaraphe neritoides were found. Another periwinkle, Littorina saxatiiis,
was also found
there, but it was distributed down to around M.T.L., with its highest density of 125/0.125
m2 at around the 9 m level.
From 9 to 4 m, a marked barnacle zone was seen, the upper
Zonation and Mylilus Islands on Rocky Intertidal of Dinard
51
part being dominated by Chthamalus montagui and the lower by Balanus balanoides.
the middle of the Balanus zone, a small number of Chthamalus stellatus was found.
limpets Patella vulgata and Patella spp. (i.e. P. aspera and P. depressa,
In
The
indistinguishable
in the field) and the mussel Mytilus edulis occurred within this level and barnacles were
found on these animals too.
Sometimes these shells were completely covered by barnacles.
In the Balanus zone the gastropods Gibbula umblicalis and Nucella lapillus were common.
A habitat segregation between G. umblicalis and G. cineraria, was recognized.
The former
species was found on rocks at the 3.5 —8m level, while the latter was common on Fucus
serratus growing at 1—5m.
Another species of Gibbula, G. magus, was collected from the
lower shore, around M.L.W.S.
The periwinkle Littorina littoralis was also found on the
Fucus serratus.
Qualitative observations around this station were also conducted.
Two crab species,
Carcinus maenas and Cancer pagurus, were found under boulders or algae, and the sea
anemones Anemonia sulcata and Actinia sp., the slipper limpet
some ascidians
Crepidula formicata,
and
were also common.
St. 2 (Fig 3) was just inside the small bay of Saint-Enogat where a sand flat
occupied the lower intertidal.
0
0
14
"
..
"
S
3
as «
8
§
£ «
0
—* =
50 100 °/e cover
50 100 No/0125 m2
100 No./100 cm 2
KHWSH
10
8
jj
M.TL6
20
60 m
M.L.WS.-
Fig. 3.
Vertical distribution of rocky intertidal organisms at St. 2.
Xanthoria parietina was not found here but a Verrucaria zone was conspicuous.
Around
M.T.L., 6.8 m above M.L.W.S., the two barnacle species Chthamalus montagui and Balanus
balanoides co-occurred and we could not find any trends in their micro-distribution pattern
in small quadrat. Many patches of the brown alga Pelvetia canaliculata were seen at the
8 —9 m level and Littorina saxatilis was common at the 5—8 m level.
Small numbers of
Patella vulgata were found in the Pelvetia zone and the gastropod Monodonta lineala was
seen at the 6—9 m level.
The zone below M.T.L. was dominated by Mylilus edulis and
Makoto Tsuchiya • Christian
52
brown algae such as Fucus vesiculosus, F. serratus and Ascophyllum nodosum.
was found not only on rock surfaces but also on Mytilus shells.
F. vesiculosus
Among the algae, several
gastropods, Nucella lapillus, Gibbula cineraria, Liltorina litloralis, and
L.
littorea, were
found. Ascophyllum nodosum and Fucus serratus densely covered rock surfaces in the more
inner part of this bay.
Many empty balanoid shells were found beneath these algae.
On the sandy tidal flat, the bivalve Mactra solida was abundant.
Many empty shells
of Crepidula fornicata were seen on the sand flat together with living ones knocked off
from the rock surface.
St. 3 (Fig. 4) was on the east side of the bay entrance at Saint-Enogat.
by various algal species including Laurencia sp., Enteromorpha sp.,
The coverage
Rhodymenia sp.,
Fucus serratus was high in the lower part of the rocky intertidal, with 100
the F. serratus at the 3 — 3.5 m level.
%
and
cover by
Fucus vesiculosus and F. spiralis were not seen
along the transect line.
50 100 °/o cover
~
50
16
100 No/0.125 m2
100 Na/100 cm2
M.H.WS-
10
M.TL6
M.L.WS-
20
60 m
0
Fig. 4.
Among the
Chthamalus montagui dominating the upper intertidal
M.T.L., Littorina saxatilis was abundant, while the
lower
dominated by Balanus balanoides among which Elminius
also seen at low densities.
barnacles.
tidal.
intertidal
from M.H.W.S. to
was overwhelmingly
modestus and
The shells of Patella vulgata were
also
C. stellalus were
covered by
small
Its congeners, Patella aspera and P. depressa, were common in the lower inter
Monodonta lineata was distributed around the 9
was abundant below M.T.L.
hangings or in crevices.
m
level
and
Gibbula
umblicalis
Aggregations of Nucella lapillus were seen under rock over-
There were many boulders at the 2 — 3 m level, the boundary
between the sand flat and rocky substratum, and Littorina littorea was found under them.
In the rock pools around M.T.L., marked growths of Enteromorpha sp. and Corallina
sp. were found.
were
Among them,
Gibbula umblicalis, Mytilus edulis and
53
Anemonea sulcata
seen.
St. 4 (Fig 5) was about 100m east of St. 3, but had different faunal characteristics.
Mytilus edulis, which was scarce at St. 3, was abundant at this station and was patchly
distributed around its lower and higher limits, with dense beds in the central part.
Com
paring with St. 3, Patella vulgata was less abundant, while Patella spp. were more abun
dant.
and
The distribution areas of these species were similar to St. 3.
lower intertidal
balanoides,
were
dominated
by barnacles,
Chthamalus
Again, the upper
montagui and
Balanus
respectively. Littorina saxatilis was mainly restricted to the upper intertidal.
The species composition of the macroalgae was similar to that of St. 3, but the coverage
was lower.
St. 3.
The density of Elminius modestus was also relatively higher at St. 4 than at
Sargassum muticum was present and Actinia and Corallina were common in rock
pools at the 8 m level.
Monodonta lineata and Patella vulgata aggregated just above the
water line of these rock pools.
St. 5 (Fig 6): This is at the entrance of a bay at Dinard, with a wide sand flat. The
distribution pattern of barnacles was very similar to that at St. 4 and Elminius modestus
was more abundant.
Littorina saxatilis was less abundant than at Sts. 1, 3 and 4, and
had its highest density at the 5 —8 m level.
Mytilus edulis was also scanty.
umblicalis was common and small algae were found in the lower intertidal.
part of the rocky intertidal, adjoining the
vesiculosus and F. serratus.
faces here and there.
sand
flat
was 60 — 70 %
covered by
Fucus
The sponge Hymeniacidon sanguinea also covered rock sur
Ascophyllum, Corallina and Codium were seen.
rock pools, Sargassum muticum, Anemonea sulcata, and
In lower intertidal
Gibbula cineraria were common.
CZ)
Fig. 5.
Gibbula
The lowest
0
0
50 100 % cover
50
100 No./0.125m2
54
Makoto TSUCMYA • Christian RETlfcRE
0
0
50 100 c/o cover
50
100 No./0.125 m2
0 100No./100cm2
M.H.WS-
M.LWS-
Fig. 6.
0
0
50 100 Vo cover
50
100 Na/0.125 m2
0 100 Na/100 cm2
Fig. 7.
55
St. 6 (Fig. 7): Around M.H.W.S., Verrucaria maura was abundant.
The coverages of
Fucus spiralis and Enteromorpha sp. were highest around the 8 m level and the 5 — 8 m
level, respectively.
Littorina saxatilis was extremely abundant and aggregated in crevices,
but it was unexpectedly scarce at the 8 m level.
than at the other stations.
Chthamalus montagui was less abundant
Balanus balanoides was abundant around the 6 m level and
small numbers of Mytilus edulis and Patella spp. were also found.
The area below the 5
m level was a sandy or boulder shore with little flora and fauna.
The
boulders
were
observed to be rolled easily by wave action.
St. 7
(Fig. 8): Although this station was very close to St. 6,
Enteromorpka sp., which were abundant at St. 6, were lacking.
Fucus spiralis and
Small numbers of Littorina
nigrolineata were found at Sts. 6 and 7. Balanus balanoides dominated the 4 — 8 m level
and small numbers of Mytilus edulis and Patella vulgata were also found in the Balanus
zone.
Patella spp. were abundant in the lower part of the Balanus zone and their shells
were covered by barnacles.
were conspicuous.
Sometimes the limpets were seen to forage and their scars
Monodonta lineata was scarce along the transect, but it was abundant
about 20 m away, with a maximum density of > 18/25 x 25 orf.
In empty shells of Chthamalus montagui and B.
Littorina saxatilis were found together with the small
balanoides at
isopod
the
8—10
Campecopea
m
hirsuta.
level,
The
abundance of the isopod was surveyed using a 10 cm x 10 cm quadrat around the 9 m
level dominated by C. montagui with a small number of B. balanoides (Table 1).
Most
of barnacles were alive
most
and 9 — 23 empty shells per 100 cnf were found.
The
abundant small animal found in the empty shells was Littorina saxatilis, a maximum of 5
0
0
50 100 % cover
50
100 NO./0.125 m2
0 100No./100cm2
Fig. 8.
56
Makoto TsucHIYA • Christian RETIERE
Table 1.
Density of littorinids and an isopod, Campecopea hirsuta, in empty barnacle shells in the bar
nacle zone where coverage of Chthamaltis montagui and Balanus balanoides was >90%.
Littorina
saxatilis was found both in the empty shells and among the barnacles.
Number of assosiated animals/100 erf
Number of barnacles/'100 cnf
No
Chthamaltis
Balanus
monlagui
balanoides
empty shelles*
Littorina
saxatilis
Melarapke
inside
outside
neritoides
Campecopea hinura
(range in single empty shells)
8 (0-2)
1
416
16
16(11)
7
0
0
2
392
17
9 (1)
8
3
2
0
3
483
33
15 (2)
19
1
3
4 (0-2)
4
388
9
13 (2)
17
1
0
5 (0-3)
5
404
38
15 (0)
32
3
6
6 (0-4)
6
510
60
14 (0)
22
0
0
2 (0-1)
7
451
42
15 (2)
25
6
0
0
8
459
36
23 (0)
26
2
2
7 (0-2)
9
423
26
23 (1)
33
3
0
9 (0-3)
10
463
91
19 (3)
42
1
0
2 (0-2)
* Mostly composed of C. montagui
individuals occurring in a single empty shell, and a small number of Melaraphe neritoides
was also seen.
Campecopea hirsuta was frequently found as a heterosexual pair, and young
specimens also occurred.
C. hirsuta sometimes occurred alone in shells and co-occurred
with one or more periwinkles.
St. 8 (Fig. 9): The innermost part of a small bay was surveyed. This station was
characterized by a scarcity of Chthamalus montagui, Mytilus edulis and Patella spp. and
by marked growths of several algal species. Among the latter, the brown alga Ascophyllum
nodosum was very abundant, attaining a 100 % coverage at the 6—8 m level.
Fucus spi-
ralis and F. vesiculosus also had high coverage values respectively just above and below
the Ascophyllum zone.
part of this bay.
Such abundant algal growths were seen around the entire inner
Balanus balanoides was less abundant than at the other stations, while
Elminius modestus, which was found on rocks covered by F. spiralis and A. nodosum, had
a relatively higher density than at the other stations.
Littorina littoralis was common on
leaves of Ascophyllum, F. serratus, and F. vesiculosus.
The
bivalve
Cardium edule was
abundant on the sandy-mud flat of the inner part of the bay.
St. 9
(Fig. 10): A wide range of rocky intertidal from E.H.W.S to M.L.W.S. was
surveyed. The density of Chthamalus montagui was low, while Balanus balanoides had an
extremely high density especially around the 8 m level. Elminius modestus, distributed
similarly to B. balanoides, was also abundant just below the Balanus zone, in the 3.5 — 4
m level.
survey.
This was the highest density (143/100 cnf) of E. modestus observed in this
The species richness of algae was high in
cineraria, Balanus crenatus, Littorina littoralis, and
the
lower intertidal
and
Gibbula
Calliostoma zizyphinum were
found
among algae.
Several patches of Sargassum muticum, 10 —20m in size, were seen in the shallow
subtidal.
Fucus serratus was abundant below the 6 m level, and it also was seen in rock
pools around the 8 m level together with Corallina and Codium.
Qualitative observations on the intertidal organisms were conducted at several places
Zonation and Mytilus Islands on Rocky Intertjdal of Dinard
cm
=
0
0
0
Fig. 9.
57
50 100 Vcover
50
100 Na/0125
100No./100cm2
Vertical distribution of rocky intertidal organisms at St. 8,
0
0
50 100 °/o cover
50
100 No./0.125m2
^ 0 JOONa/IOOcm2
14
MHWS-
10
-
MTL-j
I
6
2
M.LWSd
Fig. 10.
58
Makoto TSUCHIYA • Christian RETlfeRE
in Brittany, shown in Fig. 1. A similar distribution pattern of intertidal organisms was
recognized everywhere and the vertical distribution of each species was seen to be affected
by the tidal regime at each place.
growth, and some algal
Wave exposure also affected vertical distribution and
and animal
species, such as
Ascophyllum nodosum, Himanthalia
elongata and Elminius modestus, had a tendency to occur in sheltered areas such as the
inner part of bays.
3. Structure of mussel bed community
Mylilus edulis was abundant at Sts. 2 and 4, and many patches were found around
M.T.L. and the 5 m level at St. 4
central part of its vertical range.
(Fig. 11), where dense beds were also seen in the
In order to analyze the effects of patch size and tidal
level on the community structure of small animals associated with the patches, 60 patches,
30 from around M.T.L. and 30 at the 5 m level, were investigated.
Although algal growth
was observed on some patches, we selected patches without algae in order to exclude the
effect of the algal growths on the community.
grooves as attachment sites.
Long patches formed along
Most mussel patches used rock crevices or
Solitary Mytilus was common, also occurring on crevices.
crevices or grooves.
We selected elliptical patches for this
study.
Structure of Mytilus edulis patches
At the higher level (M.T.L.) of St. 4, mussels of all patches except for three small
ones (Nos. 19, 22 and 24) had a similar size structure, i.e. they showed a bimodal size
distribution (Fig. 12a).
Like the patches collected at higher level, two modes were also found in the size
distribution of the mussels at the lower level (5 m above M.L.W.S.) (Fig. 12b), but the
number of small individuals was larger than at
notable in patch of Nos. 1 — 5, 8, 11 and 13.
the
higher level.
This
was especially
The mussels could be divided into two size
classes even in the 2 smallest patches which had been considered at first to be solitary
individual since the small mussels accompanying them were hidden at the time of sampling.
Each patch included such components as byssus threads,
shell fragments including
Mylilus and other molluscan species, sediment, and associated animals.
Both the amount
of sediment including shell fragments and the amount per patch area increased with patch
size at both tide levels (Fig. 13).
Animals associated with Mytilus patches
Table 2 shows the species composition of small animals found in each patch collected
around M.T.L.
Lasaea rubra, Balanus balanoides, Elminius modestus, Hyale nilsoni and
Anurida maritima were abundant in many patches.
Only one individual of B. balanoides
was collected in the medium-sized patch, No. 10, where E. modestus and A. maritima were
also not found.
Even in the smallest patch, No. 30, 8 individuals of L. rubra were found,
but no other species occurred.
During the sampling process, several specimens of A.
maritima tended to escape to the surrounding area.
We collected carefully the escaped
specimens too. This species was common in many patches, nevertheless several medium-sized
patches lacked it.
Sphaeroma serratum was not found in the 4 largest patches, Nos. 1—4,
but it was rather common in medium-sized patches.
Fig. 11.
59
Patches of the mussel Mytilus edulis. a: The limpet Patella spp. were abundant around
the patches and the barnacle Balanus balanoides covered not only the rock surface but also
the Mytilus shells with high coverage,
b: small Mytilus patches.
was covered by B. balanoides. c: a solitary Mytilus.
Surrounding rock surface
60
Number
of
individuals
20
10
0
10
20
12(22)
(18)
l<13>'09)i(22)i(9)'(6)'(5)
™ ^^F^Io^K* W^l™
0
10 0
10 0
10
0
10
0
16
(43)
0
100
1Q0'1Q0
IQO'10
"0 IPO
IPO ' 1QQ
1QQ
100
1Q0
1Q0
1QQ
1Q
10
15
20
25
30
35
40
45
50
Fig. 12.
17
(29)
18
(30)
19
(19)
26
(7)
27
01)
28
I 29
(9) 1(9)
30
(6)
Size distribution of mussels in Mytilus patches a: around M.T.L., and b: 5 m above M.L.W.S.
Each histogram labeled:patch number (number of individuals).
50
61
0.5
O
o
o
r a 0.4264 (P<0.05>
0.05
I
en
Y= 0.0232 X1-3384
r = 0.8873 (P<0.001)
S
=6
0)
0.01
i
0.005 |
0.5
9!
• •
0.1
-•-♦
0.001
50
0.5
0.1
0.0207 X 02A98
r=0.3990 (P<0.05)
O
0.05
Y= 0.0191 X1-2690
1
m 0.9113 (P< 0.001)
0.005
0.5
10
Fig. 13.
0.01
Area (cm2)
100
Relationships between patch size and amount of sediment (solid circles) and amount of sedi
ments per unit area (open circles) in the patches a: at M.T.L. and b:5 m above M.L.W.S.
62
Table 2.
Faunal list for all patches (Nos. 1—30) at M.T.L. The length, width, maximum height, and area of
parentheses for some animals are those found on the bare rock surface from which the respective patch
7
8
9
10
11
12
13
208
165
145
145
172
115
135
126
98
92
80
85
98
109
110
116
76
85
75
68
74
56
54
52
38
42
36
39
38
46
43
42
27
29
26
28
81.0
72.5
64.1
54.3
40.4
34.2
34.2
6.0
4.1
3.8
2.2
5.0
2.7
3.6
1
1
1
Length (mm)
Width (mm)
Maximum height (mm)
215
143
42
Area (erf)
Amountofsediment (g)
241.8 153.9 125.6 120.9 120.9 100.5
18.8
14.5
35.2
11.8
63.2 43.5
Actinia equina
unidentified nemertinean A
unidentified nemertinean B
unidentified nemertinean C
Syllis arnica
unidentified syllid
Trypanosyllis zebra
Perinereis cultrifera
Cirriformia tentaculala
unidentified oligochaete
2
2
6
1
2
-
1
-
-
-
-
-
-
6
-
-
1
-
-
1
-
-
-
-
-
-
-
2
-
1
-
-
-
-
-
-
1
-
40
27
9
16
9
3
-
-
-
-
-
-
-
1
327
Ill
46
96
223
191
146
164
103
31
15
8
12
28
23
16
19
14
-
-
2
-
-
-
-
-
-
Campecopea kirsuta
-
-
-
1
-
-
-
-
-
-
Spkaeroma serratum
-
-
-
-
13
52
15
13
5
-
1
6
-
18
14
59
1
3
2
2
-
6
-
-
-
-
-
-
-
-
-
-
-
-
Balanus balanoides
Elminius modesius
unidentified tanaid
Jaera albifrons
Jaera sp.
12
11
-
1
-
-
Hyale nilsoni
51
24
10
22
21
19
18
16
6
20
14
3
5
Hyale periori
1
1
1
4
3
9
-
-
4
1
1
-
1
1
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
1
1
-
-
unidentified amphipod A
-
unidentified amphipod B
-
-
1
-
-
-
-
-
2
3
4
2
4
1
-
2
-
1
1
-
-
-
-
-
-
-
-
-
-
14
41
13
109
28
77
136
19
-
6
28
54
Carcinus maenas
unidentified crab (young)
Anurida maritima
11
1
-
-
-
-
-
-
-
-
-
-
-
1
-
unidentified chironomid
2
3
-
4
2
1
-
2
-
-
-
-
1
unidentified dipteran A
2
-
-
1
2
3
1
-
1
1
3
3
1
-
-
-
-
-
-
1
-
-
-
-
-
-
-
-
-
-
-
- (1)
-
-
- (1)
-
-
-
-
-
-
-
unidentified mite
unidentified dipteran
Acanthochites discrepans
-
Patella aspera
1
Gibbula umblicalis
-
1
-
2
-
-
4
-
1 (2)
-
-
-
3
-
-
-
-
-
-
(1)
(1)
(1)
Littorina saxatilis
5
-
4
-
3
3
-
-
3
-
1
-
Cingula cingillus
3
3
1
-
1
1
-
4
-
1
-
-
Bittum reticulatutn
_
_
_
_
_
_
_
Rissoa litacina
-
-
-
Chrysallida sp.
4
-
-
-
-
-
-
-
2
-
-
1969
2294
670
1643
818
1986
Modiolaria disors
-
-
Atnphipholis squamata
-
-
1
-
-
1
-
-
18
16
23
15
2430
2515
801
1917
1
_
_
_
-
-
-
-
-
-
-
-
-
-
-
583
785
433
443
549
302
282
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
20
14
12
12
13
10
12
10
10
1221
2368
797
1145
593
471
639
381
358
Bitium sp.
Lasaea rubra
Number of species
Number of individuals
♦ looks like a solitary mussel from outside view
** solitary mussel
1
each patch, and the amount of accumulated sediment are also shown.
had been removed one month
63
Numbers of individuals shown in
earlier. +:present.
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
95
70
70
65
65
65
65
48
53
45
54
43
40
35
40
42
43
42
42
42
38
35
45
40
30
32
35
21
21
15
_
_
27
22
19
18
21
25
25
26
32
21
22
24
19
19
15
_
_
31.7
24.2
23.1
21.8
20.7
19.7
17.0
16.6
16.3
13.9
13.6
12.4
6.3
5.3
5.0
1.4
0.8
7.6
1.4
2.0
0.4
6.3
0.7
0.7
0.2
0.9
4.4
0.8
0.2
0.1
0.04
0.1
0.1
0.05
8
3
4
6
6
8
3
60
39
27
33
3
22
8
24
29*
30* •
-
17
5-626331
-71321--
1
5
2
-
1
-
-
-
-
2
23--------------
733-115161---114-1--3--2----1-
1
-----
1
.
-
1
-
5
2
10
4
15
1
--_...___.
1
2
1
-
1
4
__
--
5
14
1
--------
1
...
_
20
-
3
.
11--3-2-1--2-2--
-(2)
296
10
404
-
278
-
-
-
-
-
-
1
-
1
1
3
-----
90
159
141
99
286
866
295
161
168
10
6
11
165
144
337
97
-(2)
174
-(2)
277
-
63
91
1
57
38
43
25
8
6686577531
139
203
312
76
130
73
66
68
45
8
64
Table 3
Faunal list collected in each patch at 5 m above M.L.W.S.
2
3
182
164
51
245
120
52
165
113
36
+
+
-
1
-
-
-
-
1
Length (mm)
Width (mm)
Maximum height (mm)
Area (cnf)
Amountofsediment (g)
Hymeniacidon sanguinea
Actinia equina
unidentified nemertinean
unidentified polynoid
Eulalia viridis
unidentified phyllodocid
Syllis arnica
unidentified syllid A
unidentified syllid B
Trypanosyllis zebra
Perinereis cuitrifera
unidentified lumbrinerid
Cirriformia tentaculata
A
B
C
D
Cirraturus cirralus
unidentified spionid
Terebella lapidaria
Amphitrite gracilis
unidentified oligochaete
unidentified bryozoan
Balanus balanoides
Elminius modestus
unidentifide tanaid
Sphaeroma serratum
Jaera albifrons
Jaera sp.
Hyale nilsoni
Hyale periori
unidentified amphipod A
unidentified amphipod B
unidentified amphipod C
Jassa sp.
Carcinus maenas
unidentified
crau
unidentified crab C (zoea)
ifXJ^J
uniueniiiieu
150.7
10.1
6
146
117
2
2
141.3
14.8
1
-
1
1
-
7
145
100
42
32
140.2 116.6
13.3
5.3
4
1
-
-
-
-
9
10
11
136
126
118
8
135
86
37
98.9
4.0
-
92
30
98.9
3
1
3
-
-
-
-
-
-
-
-
1
-
-
-
-
-
-
-
4
-
-
-
-
2
-
1
1
1
2
-
1
3
1
1
1
2
2
-
_
1
1
1
2
1
9
1
2
-
5.1
1
1
-
2
98
26
96.9
17.9
-
-
-
84
34
77.8
10.4
1
2
1
-
-
-
-
-
-
-
-
1
2
2
-
-
-
-
-
-
-
-
1
-
1
3
1
-
-
-
-
1
1
-
-
-
-
1
13
100
85
46
69.1
11.6
-
2
-
1
-
3
-
12
99
84
27
72.2
4.1
2
-
2
1
1
-
2
1
4
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
1
-
-
1
-
2
-
-
-
-
-
-
1
-
-
-
-
+
+
880
58
961
253
641
91
692
116
509
141
542
47
108
42
346
54
128
11
224
17
-
-
-
-
230
59
1
359
29
-
598
78
1
-
-
-
-
-
21
9
23
-
-
3
1
3
1
-
-
1
-
-
-
-
-
-
-
-
-
-
12
4
3
6
1
45
13
13
10
14
11
1
12
8
15
-
-
-
-
-
-
-
-
-
-
-
-
1
4
8
1
1
1
8
11
1
7
5
4
4
3
-
-
-
-
-
4
1
5
-
-
-
-
-
2
5
2
-
-
1
1
3
11
6
6
7
4
-
1
-
-
-
■
8
1
4
-
i
i
-
11
-
i
i
1
a
unidentified crab B
• J
231.7
45.2
234.3
14.4
5
180
100
39
4
145
110
37
142.4
11.3
Conventions as in Table 2.
L
2
-
-
_
_
2
3
_
_
-
-
-
-
-
-
-
-
-
-
KD
-
4
-
-
LLLf I JL
-
mne
unidentified chironomid
unidentified dipteran
Acanthochites discrepans
Patella aspera
Patella depressus
Gibbula umblicalis
Gibbula cineraria
Littorina littorea
Littorina saxatilis
Littorina nigrolineata
Littorina littoralis
Cingula cingillus
Bitlum reliculalum
Bittum sp.
Rissoa litacina
Nucella lapillus
Ocenebra erinacea
Chrysallida sp.
Lasaea rubra
Modiolaria disors
Number of species
1
3
-
2(1)
1
6
3
9
1
2
2
-
-
-
7
1
14
1
3
3 (1)
-
1
4
2
4
158
1
4
2
6
401
29
1190
-
-
-
-
-
2
3
1
-
-
-
-
-(3)
- (2)
5
2
-
-
-
-(1)
-
1
-
2
1
1
1
2
-
-
-
-
1
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
1
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
2
-
-
-
-
52
1
60
96
-
-
4
148
1
14
17
16
255
18
423
-
-
1
-
1
2
2
1
-
-
-
3
194
1
186
169
47
-
279
3
181
-
1
723
3
-
-
-
-
28
1755
21
1523
19
1051
17
967
21
907
13
804
17
489
17
468
* looks like a solitary mussel from outside view
2(1)
-
1
-
-
-(1)
1
-
1
(1)
-
1
1
-
1
3
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
3
-
2
_
1
-
-
9
3
-
(1)
3
_
_
-
1
-
2
1
3(1)
1
2
1
1
239
498
-
14
"lO8
69
36
59.3
2.4
15
86
79
25
16
17
92
84
54.0
2.1
70
28
50.6
2.5
58
33
38.2
1.4
1
-
-
18
19
85
53
22
74
58
18
20
82
36.1
0.7
33.7
0.5
44
31
27.6
0.7
1
1
-
21
72
43
20
24.9
0.8
-
2
1
1
1
97
24
1
14
49
21
19.6
0.3
-
1
1
_
1
1
1
239
61
80
1
-
-
12
2
-
41
32
15.7
0.8
I
24
45
40
22
14.4
0.3
25
55
24
21
10.6
0.9
I
I
41
29
26
27
28
51
24
22
9.4
0.4
32
29
14
7.5
0.5
40
23
15
17
28
11
7.2
0.4
29*
30**
-
_
_
3.7
0.5
2.5
0.02
3
1-21
-
64
23
50
1
3
-
29
53
1
-
171
22
65
5
2
-
-
-
99
124
83
40
18
-
-
1
-
32
1
41
4
-
-
822816
11
1
2-
1
-
-
I
6
I
3
-
2
I
-
I
-
-
I
38
9
I
I
7
-
--1-2-1-_____
54-22231-l-----{I
1
'I
I
I
I
_
I
1
2
5
-
1
2
-(1)
-
-
-
1
-
1
-
l"
~-
"-
I
_
-
-
1
-
-
1
-(1)
-
-
-(1) '-
'-
'-
'-
-
-
I
1(1) I
i
-
.
.
:
:
1
-(1)
I
i
I
I
-(1)
-
I
I
I
:
id) :
:
:
1
b
-
-
1
1
-
1
-
-
-
-
-
-
-
-
-
-
137
117
77
68
57
17
48
59
19
13
17
18
18
28
20
11
1
3
10
164
7
65
9
40
5
66
8
56
4
39
6
61
5
34
7
60
2
12
13
370
1
10
260
10
389
16
159
1
13
160
1
12
158
10
228
66
Makoto TSUCHIYA • Christian Reti£re
The species composition of abundant animals in the patches at the lower level (Table
3)
was similar to that of the higher one, but the density was very different for some
animals. Species commonly found at both levels were Sytlis arnica, Perinereis cultrifera,
Balanus balanoides, Elminius modestus, Jaera albifrons, Hyale nilsoni and Lasaea rubra.
Anurida maritima was not found at lower level.
Lasaea rubra was less abundant in lower
patches than in upper ones, while the reverse trend was seen in Elminius modeslus.
The
number of annelidan and molluscan species was larger in the lower patch group than in
the higher one, while that of arthropod species was similar in both.
Patch size vs associated fauna
1) Patch size vs species richness and abundance
The number of species increased with patch size around M.T.L., while
density (number of species/area) decreased (Fig. 14a).
the
species
The number of individuals simi
larly increased with patch size, but the density (number of individuals/area) was relatively
constant (Fig. 14b).
Similar trends were recognized for the associates of the mussel patches in the lower
intertidal (Fig. 15a, b).
The density was lower in lower patches than in higher ones.
2) Patch size vs species diversity
The species diversity (H1) of the associated animals both in higher (Fig. 16a)
lower (Fig. 16b) patches
did not show any trend with patch size.
and
Species diversity was
relatively lower among the associates of higher patches (mostly <1.0) than among those
of lower ones (mostly >1.0).
On the other hand, Pieleu's equitability (J') decreased with patch size (Fig. 16a,b).
It was lower among the associates of higher patches than among those of lower ones.
3) Patch size vs abundance of each species
The
relationship between patch size and the abundance of some common species was
analyzed (Figs. 17 and 18).
Higher patches: For all species analyzed, the number of individuals increased with
patch size.
However, the densities of Elminius, Hyale, Sphaeroma and Anurida significantly
decreased with patch size.
But in the case of Sphaeroma, many patches lacked this species
and the calculations were done using the adjusted value of N (total number of individuals)
+
1 for all patches.
When the calculations were done only for the patches harboring
this species, the density did not show any trend with patch size.
Lasaea was collected from all patches and more specimens occurred in larger patches.
Its density did not vary much with patch size.
Balanus was also abundant, the number of
individuals increasing with patch size.
was a
There
wide
variation
in
the density
of
Balanus in the medium-sized patches, 15 — 60/cnf, while its density was rather constant
in both smaller and larger patches.
Jaera occurred mainly in larger patches and its total
population increased with patch size.
Lower patches: The abundance and density of Lasaea showed similar trends to those
above (Fig. 18a), but the density was higher in lower level patches.
Balanus was also
more abundant in larger patches and its density was rather constant (Fig. 18b).
The
abundance of Elminius showed a similar trend, but no trend was recognized in its density
with patch size (Fig. 18c).
Jaera occurred mainly in larger patches at the lower as well
as higher level (Fig. 18e).
Hyale and Carcinus were also more abundant in larger patches
67
5
50
~
CM
U
s
0.5
i
(A
01
"8
0.1
Y=2.0779X~a5822
r=0.9508 (P<0.001)
aos
Y=13.1723 X09596
1000
100
r=Q9541 (P<0.001)
50
500
XJ
u
'>
1
(0
10
100
1
50
3
10
1
5
10
50
100
Area ( cm2)
Fig. 14.
Relationships between patch size and a:number of species and b:number of individuals around
M.T.L. Solid circles: numbers of species or individuals, and open circles: numbers of species or
individuals per patch area.
68
50
Y=2.1667 XQ4A61
r=0.9159 (P<0.001)i
7
<u
1
10
i
a.
0.5
I
Y=2.1657X-°-5538
r=-0.9A29(P<0.001)
1000
ai
ft
100 ~
Y=5.3795X10079
I 500
r=0.9536 (P<0.001)
50
•p
*>
a
2.
100
H5
50
I
10
I
I
I
I
50
I
M
100
Area ( cm* )
Fig. 15.
Relationships between patch size and a:number of species and bmumber of individuals around
5 m above M.L.W.S.
Solid circles:number of species or individuals, and open circles: number
of species or individuals per patch area.
2.0
69
1.0
= 0.2040logX* 0.6521
=-0.6657 (P<0.001)
1.5
0.8
0.6
1.0
0.5
"1
L+LJ.
J
1
1
'
i
i
i i i
J
I
I
■
i
i
i
i i
2 2J0
1.0
a
0.8
1,5
0.6
#•
IX)
0.4
Y=-0.1906 tog X* 0.8094
r=-0.8498 (P<0.001)
0.5-
0.2
1
Fig. 16.
10
Area (cm?)
Relationships between patch size and species diversity (\f)
equitability (J')
100
(solid circles)
and Pieleu's
(open circles) of small animals in the patches a:at M.T.L. and b: 5 m above
M.L.W.S.
(Fig. 18d and f).
Although significant correlations between patch size and the density
of Jaera, Hyale and Carcinus are presented in Fig. 18d—f, they are affected by the same
statistical artifact described above for Sphaeroma.
When the patches harboring no specimens
of these species were excluded from the calculations, no trend was recognized for the
relation between their density and patch size.
4) Patch size vs size distribution of Carcinus (Fig. 19)
This crab was scarce in the higher patches: 0 — 4
patch.
individuals were found in each
Small individuals (<3.0 mm in carapace width) were found in smaller patches.
In the two largest lower patches, larger individuals were found in comparison to other
patches.
Other marked relationships between patch and crab sizes were not recognized.
70
lOOOh
P
Y.96S19X09475
a
r, 0.9024 (P'OOOI)
100
Area (cm )
10
1
Fig. 17.
100
Relationships between patch size and abundance of some associated animals in patches at
M.T.L. Abundance
Balanus
balanoides,
(solid circles)
c-.Eltninius
serratum and g:Hyaie nilsoni.
and density
modestus,
(open circles)
fr.Anurida
maritima,
are shown.
e:Jaera
aiLasaea rubra, b:
albifrons,
i.Sphaeroma
For b-g, number of individuals is expressed as N + 1.
mx>c
10
71
WOO
:
b
y.mkox1*3*0
r.09335 (P<OjOOI)
KM-
i
too-
O
• QJ
•
10;
|
1
it.
100
u
M
1
. V-O309BX01800
* rwoaom (p<om)
o
■ i 'in
10
1—
on
Qt
10-
001
1
aoi
100
10
Area
Fig. 18.
C01
100
(cm )
Relationships between patch size and abundance of some associated animals in patches at 5
m above M.L.W.S. Abundance
(solid circles)
and density
(open circles)
are shown. &\Lasaea
rubra, biBalanus balanoides, ciElminius tnodestus, d:Hyale nilsoni, eiJaera albifrons and i'.Carcinus
maenas.
For c-f, number of individuals is expressed as N + 1.
5) Invasion of bare rock surface following mussel removal.
About one month after the removal of the mussel patches,
were found on the newly exposed bare rock surfaces.
The
some
molluscan species
species involved and their
number of individuals are shown in the Tables 2 and 3 with parentheses.
At the higher level, only one species, Patella aspera, was found, and it was relatively
Makoto TsucHIYA • Christian Retiere
72
E
6
11 '18 '24
2
2
u
16
Fig. 19.
Size distribution of Carcinus maenas in each patch at a: M.T.L. and b: 5 m above M.L.W.S.
common where larger patches had been removed.
the abundance of P. aspera was
No relationship between the area and
recognized, because there were several larger bare rock
surfaces lacking it.
Five species, P. aspera, P. depressa, Littorina saxatilis, L. littorea and Gibbula umblicalis, were found on the lower exposed surfaces.
areas,
but
other species showed no
trends.
G. umblicalis tended to occur in larger
Several
specimens of Balanus
balanoides
were seen on the shells of Patella spp.
Discussion
1. Zonation of rocky intertidal organisms
The zonation pattern of intertidal organisms along the coast of Dinard was essentially
the same as that of English coasts described by Lewis
(1964)
and Southward
and very marked zones of lichens, littorinids, barnacles, limpets,
were recognized.
In addition, other gastropod species had
(1965),
mussels and seaweeds
its own distributional areas
and some congeners showed a habitat segregation, i.e. Gibbula umblicalis, G. cineraria and
G. magus as the most conspicuous example. G. umblicalis
occurred at the 4 —7.5m level,
while G. cineraria at the 1.5 (around M.L.W.S.) — 4m level. G.
algal growths at a lower level.
magus was found among
The environmental requirements of these gastropods and
competition among them may be themes for future investigations.
Some differences from the descriptions made by previous workers should be explained.
The
first one
concerns the distribution
of
chthamalid
barnacles.
Southward
(1976)
reviewed the common intertidal barnacles of Britain and reported that Chlhamalus montagui,
73
which has been considered as a growth form or variety of C. stellatus, occurs commonly
on
sheltered coasts. Where both species coexist in a shore, C. montagui is dominant at
higher tide levels, and C. stellatus at lower tide levels.
Although he had not found C.
stellatus around M.T.L. at Dinard at that time, we confirmed that small numbers of
C.
stellatus occurred at lower levels than C. montagui. According to Southward (1976), 25%
of the chthamalids at M.T.L. at Roscoff were C. stellatus and the others C. montagui.
Factors affecting the
differences in distribution
between
Balanus balanoides as elegantly demonstrated by Connell
Chthamalus stellatus and
(1961a,
b)
were competition
between these two species, differences in their tolerance to physical conditions, and the
effects of predators.
In the present study,
balanoides overlapped.
Interactions among these three species should be analyzed in the
future.
the distributions
of
C.
Moreover, there is another small barnacle on the same shore.
stellatus and
B.
Elminius modestus
immigrated by ship from Australia in the early years of the Second World War and was
first found on the English coast (Stubbings, 1950; Crisp, 1958).
The history of the
spread of this species has been reported by several workers (Den Hartog, 1953; Crisp,
1958; Crisp & Southward, 1959) and Bishop & Crisp (1958) reported the distribution of
this species along the French coast.
In the present study, E. modestus was found at all
stations, being most abundant at St. 8 which is a sheltered point and St. 9, nearest part
to the mouth of the Ranee River.
At. St. 9, E. modestus was abundant at the 3 — 4 m
level, where Balanus was very scarce.
They may be competitors with each other.
In
order to invade a new locality, it is necessary to outcompete other species having the
same ecological niche and expel it (or them), or there must be some vacant space for in
vaders.
Lewis (1964)
reviewed these papers and argued that sheltered estuarine bays,
creeks and harbors which may warm up in summer are the best environment. In the case
of the rocky shores around Dinard, it is possible that Sts. 8 and 9 were the
sites of
original colonization of E. modestus.
The brown alga Sargassum muticum is well known as an invasive introduced species
from Japan
(Norton, 1976; Norton & Fetter, 11981).
This alga was seen at several
stations in the present survey and more abundantly on rocky or boulder shores in front
of the Roscoff Marine Biological Station. Around Dinard, it was abundant at Sts. 1 and
9. In the shallow subtidal, 1 —2m deep at spring low tide, it was observed on boulders at
St. 1. There are no suitable habitats for S. muticum at the other stations because the
lower intertidal and shallow subtidal consisted of
sandy flats.
2. Habitat for isopod and periwinkle provided by empty barnacle shells
Occupation by the isopod Campecopea hirsuta of empty barnacle shells on the higher
intertidal, sometimes together with one or more
small
specimens of
Littorina saxatilis,
was already reported by Wieser (1963) and Harvey (1968). Panouse (1940)
that this isopod occurs among the lichens and Colman (1940)
lOOg of damp weight of Lichina pygmaea.
reported
found 3772 individuals per
Since we did not survey the fauna associated
with seaweeds, we did not confirm whether this isopod occurs among the seaweeds around
Dinard.
A similar phenomenon has been found in the higher intertidal of central Japan.
Nishimuraia paradoxa Nunomura (1988) occurs in empty shells of Chthamalus challengeri,
which is the common barnacle in the temperate area of Japan
barnacle shells probably play
an
important
role
in
(Tsuchiya, unpubl.).
creating a
habitat
for
Dead
Campecopea
74
Makoto TsuCHIYA • Christian Retiere
hirsute because Lichina was very scarce at St. 7, where many isopods were found.
In
the Lichina pygmaea zone, Pelvetia canaliculata and Fucus spiralis occurred but Colman
(1940) did not find this isopod among them.
This substratum microtopography created by barnacles provides spatial
small germlings of algal species (Lubchenco, 1983)
beds in the barnacle zone.
refuges for
resulting in the occurrence of algal
The fact that barnacles enhance the settlements and survival
of limpets by several ways including providing protection from desiccation, wave action and
grazing (Branch, 1976; Choat, 1977, Creese, 1982; Hawkins, 1983, Miller & Carefoot,
1989).
When barnacles exfoliate as a mass, a gap appears there.
occasionally observed in the
barnacle
zone,
where
it
Various sized gaps are
is densely
distributed,
and some
motile animals such as limpets and periwinkles (Tsuchiya, 1984; Farrel, 1989).
In this
study area, gaps were not common and barnacle covered the rock surface even around the
limpets Patella spp. on which barnacles were seen to attach
(Fig. lla).
Patella spp. was high and they have to forage on the barnacle shells.
Density of
When foraging,
their scars were conspicuously seen on the barnacle zone.
3. Mytilus islands as a habitat for small animals
Our study on the community structure of small animals associated with
Mytilus edulis provided useful information on their community ecology.
patches of
Mussel patches on
the rocky coasts are considered to be a model of islands because most of the small animals
such as polychaetes, amphipods, and crustaceans cannot live on the bare rock surface but
only within the patches.
Therefore, analyses of the process of community organization of
the associated animals may be useful for understanding community ecology in general.
Species richness increased with patch size.
This
phenomenon
communities on real island (see MacArthur & Wilson, 1967)
is well
known
for
and is related to the fact
that the environmental heterogeneity is greater on larger islands.
In
the case of
our
island system, the habitats for the small animals were divided into several categories, i.e.
on the Mytilus shells, among Mytilus byssus threads, and within or on the sediment.
The
space between the Mytilus shells is also an available habitat for relatively large mobile
animals such as crabs and gastropods.
This was demonstrated in a previous paper by the
senior author (Tsuchiya & Nishihira, 1985).
Larger patches contained a larger amount
of sediment, resulting in an increase in the number of
individuals of
The amount of sediment per patch area also increased with patch size.
accumulates easily
in
larger patches.
Moreover,
biodeposits,
produced by Mytilus may also accumulate (Tsuchiya, 1980).
infaunal species.
Sediment evidently
faeces and pseudofaeces,
Since the latter include much
organic material (Tsuchiya, 1982), they may be used as food by the smaller associates
in the patches.
If there is a strongly dominant species in the sediment, the community
may show a low species diversity.
Although species diversity did not increase with patch
size in the present case, we did not find such an abundant species.
the sediment are partitioned among many species.
Perhaps resources in
Nevertheless, some species interactions
may occur in larger patches, because equitability decreased with patch size.
The most
abundant species was not an inhabitant of the sediment, but the bivalve Lasaea inhabiting
the byssus threads or the lower parts of Mytilus shells or barnacle on the shells.
Of
course, a detailed biological understanding is needed to clarify the relationship between
75
the number of microhabitats and the life of each associated animal species.
The number of species was larger in patches collected in the lower part of the inter
tidal than in higher ones, and differences in the species composition were recognized.
general, species richness was higher in the higher patches.
for polychaetes and molluscs.
In
This was especially conspicuous
Lasaea rubra was extremely abundant in the higher patches,
but it was less abundant in the lower ones.
This species was collected from all patches,
even
levels.
from
solitary mussels,
at
both
tidal
A
similar species composition
was
recognized in the arthropod assemblages, Anurida maritima being found only in the higher
patches. The degree of desiccation and exposure to high temperature at
low tides may
affect the species composition of the associated fauna.
The species density (number of species per unit patch area)
size.
decreased with patch
This may be explained by species richness reaching a plateau specific to the tide
level, and the possibility that the
number of
individuals of some
occupy a wide area resulting in fewer resources for other species.
species increases to
By making secondary
space, though, Mytilus patches do play a role in increasing species richness and species
diversity in the rocky intertidal community.
The number of individuals increased with patch size and the density was relatively
constant.
This was quite different from the results of our previous work on the mussel
community (Tsuchiya & Nishihira, 1985)
and on coral-associated communities (Tsuchiya
et al., 1986, 1989b). The great abundance of barnacles such as Balanus balanoides and
Elminius modestus and the small bivalve Lasaea rubra might cause this. These small animals
are suspension feeders, so it is unnecessary for each individual to have a wide space, e.g.
barnacles can be attached to Mytilus shells in a dense aggregation, in contact with each
other. Some Mytilus shells could not be seen to the complete cover of barnacles.
feeders, carnivores and grazers have to forage and need wider spaces.
viduals that need more space inhabit larger patches.
Large specimens of Carcinus maenas
was found in the two largest patches and Tsuchiya and Nishihira
larger specimens of the
patches.
polychaete
Typosyllis adamanteus
This was also true for the xanthid crab
coral Pocillopora damicomis (Tsuchiya et al.,
Deposit
Thus larger indi
(1985)
reported that
kurilensis occurred
in
larger
Trapezia cymodoce associated with the
1989a).
These animals may affect the
species composition of the communities via intra- and/ or inter-specific interactions in
different ways in different sized islands. No marked relationship between the sizes of the
crab Carcinus maenas and mussel patch was found in the present study.
Since C. maenas
is well known to migrate much in various habitats
1971), detailed
(Wolf & Sandee,
obsrevataion on the behavior within the mussel patch is needed with reference to tidal
behavior.
4. Species diversity in the mussel zone
As described above, patches of M. edulis play an important role in increasing species
diversity by harboring small animals.
In addition, barnacles cover the rock surface around
the mussel patches to a high degree and Patella spp. are also common there (Fig. 11).
The gastropods Gibbula umblicalis, Nucella lapillus and Littorina littorea, and the brown
alga Laurencia sp. also occurred as primary space users around the mussel patches at the
5 m level above M.L.W.S. (Fig. 5), occurring in crevices or beside the patches or barna
cles, but they were scanty around the mussel patches at M.T.L.
Small
littorinids
were
76
Makoto Tsuchiya • Christian Retiere
also collected from empty barnacle shells.
Therefore the species diversity was higher in
the lower mussel zone than in the higher one.
This was also true
for the
associated
animals within the Mytilus patches.
In the mussel zone, a mosaic distribution of several animals is observed even in the
central part of this zone, where dense beds of Mytilus occur (Fig. 20).
In a quadrat on
a bare, smooth rock surface in the mussel zone (Fig. 20a), few animals could be found,
i.e. the species diversity is very low.
If there are some crevices on the surface, littorinids
can occur (Fig. 20b).
Littorinids may also be found in areas in which barnacles have a
scattered distribution
(Fig. 20c).
Hence they are usually found beside the barnacles,
probably because they require surface irregularities.
Limpets, whose shells were frequently
covered by barnacles, are also seen as primary space users.
The carnivorous gastropod
Nucella lapillus was collected on areas densely covered by barnacles.
Undoubtedly, the
barnacles are a food resource for them and feeding by Nucella results in the appearance
of bare rock surface which is an available habitat for limpets and/or littorinids (Fig.
20d, e). A higher species diversity was observed for organisms in quadrats containing a
small Mytilus patch (Fig. 20f), because the Mytilus patch enhances species diversity by
harboring small animals.
The diversity index may be even higher in a quadrat in which
a larger patch occurs (Fig. 20g).
If the whole area in a quadrat is covered by a large
Mytilus patch (Fig. 20h), it may be difficult for large limpets to live there.
the diversity, may be high.
Nevertheless,
Namely, the species diversity is determined by the three-
dimensional structure constructed by organisms on the rocky surface, and a more complex
structure, which is considered to have greater environmental heterogeneity, harbors more
species.
Menge & Sutherland (1976) suggested that in structually complex environments,
competition
may increase diversity through increased
habitat specialization.
However,
there is unexpectedly little information about the kinds of environments in a given habitat,
how each species uses each environment, and how and whether animals compete with each
other.
These are themes for future investigations.
In discussing species diversity, we must specify which area is under discussion, e.g.
within a very small quadrat or the whole of the mussel zone, etc.
If we use a very
small quadrat for counting these animals, the variety of data obtained will depend upon
the quadrat position.
If a large quadrat is used to sample the area, micro distributions
of most species will not appear in
the data.
Many comparisons have been made
for
communities located in different places or developing on different substrata, e.g. homoge
neous and heterogeneous surfaces, and the conclusion by
Menge et al. (1985)
that the
diversity of an area is closely related to its spatial characteristics, e.g., scale and dis
creteness of substrata, is also relevant.
The effect of consumers on the diversity of
primary space users has been well documented
(e.g. Paine, 1966,
1974; Paine et al.,
1985; Menge et al., 1985), but their ways in which consumers affect the community
structure of the rocky intertidal of Dinard are still unknown.
Open space made by the
feeding by Nucella may be utilized by some limpets and littorinids, resulting in increased
species diversity in barnacle-dominated areas.
Acknowledgements
This study was conducted as a part of the cooperative research program between the
Japan Society for the Promotion of Science (JSPS) and le Centre National de la Re-
Zonation and Mytilua Islands on Rocky Intertidal of Dinard
•
Fig. 20.
bare rock
limpet
^—* crevice
£&#
* Nucelta
barnacles
$2z? Mytilus
Diagrammatic representation of a mussel zone.
v
77
littorinids
A cross-sectional view of the zone is also
shown on the bottom, but motile animals such as limpets and littorinids are not shown.
For
details, see text.
cherche
Scientifique
(CNRS), which awarded a
fellowship
to
M.
Tsuchiya.
Drs.
J.
Cabioch and J-C. Dauvin identified some algal and molluscan species, respectively.
Drs.
D. Bellan-Santini, G. Bellan, P. Lasserre, and C. Emig helped us in various ways.
Mr.
A. Chenu guided one of us (MT) around the shore of la Garde Guerin.
held with many staff members and students of the
Museum National d'Histoire Naturelle, those of the
Laboratoire
Station
Biologique
those of the Laboratory of Ecology, University of the Ryukyus.
Dr. M. Grygier kindly reviewed the manuscript.
Discussions were
Maritime
de
de
Dinard,
Roscoff
and
Prof. K. Yamazato and
Many thanks are due to everyone mentioned
above for their kind help in this study.
References
Ancellin, J., P. Le Gall, C. Texier, A. Vilquin & C. Vilquin, 1969.
Observations sur la distribution
de la fauna et la flora dans la zone de balancement des marees le long du littoral du nordouest
du Cotentin.
Mem. Soc. natio. ScL nat. math.
Audouin, J.V. & H. Milne-Edwards, 1832.
Cherbourg, 52: 139—199.
Recherches pour servir a l'histoire naturelle du littoral
de la France.
Bayne, B.L.
(ed.) ,
1976.
Marine Mussels:
their ecology
and
physiology.
Cambridge
University
Press, Cambridge, 506 pp.
Beauchamp, P. (de), 1914.
Les greves de Roscoff.
de balancement des marees Paris.
Etude sur la repartition des etres dans la zone
78
Beauchamp, P.
(de), 1923.
Quelques remarques de bionomie marine
sur les iles
Chaussey.
Bull.
Soc. ZooL France, 48: 84—95.
Beauchamp, P.
(de)
& R. Lami, 1921.
La
binomie intercotidale de
File de
Brelhat.
Bull. Biol.
France, et Belgique, 55: 185—238.
Bellan-Santini, D., 1963.
Comparison sommaire
superieur en Manch et en Mediterrannee.
Benard, F. 1960.
Roscoff.
Branch,
quelques
peuplements rocheux de l'infralittoral
La faunule associee a Lithophyllum incrustans Phyl. des cuvettes de la region de
Cak. Biol Mar., 1: 89-103.
Bishop, M.W.H. & D.J. Crisp, 1958.
France.
de
Rec. Trav. St. Mar. End., 30: 43—75.
The distribution of the barnacle Elminius modestus Darwin in
Proc. ZooL Soc. Lon<L, 131: 109-134.
G.M.,
1976.
Interspecific competition
experienced by
South
African
Patella
species.
J.
Anim. EcoL, 45: 507-529.
Choat, J.H., 1977.
The influence of sessile organisms on the population biology of three species of
acmaeid limpets.
Colman, J. 1940.
J. Exp. Mar. Biol. EcoL, 26: 1—26.
On the faunas inhabiting intertidal seaweeds.
Connell, J.H., 1961a.
populations of the barnacle Balanus balanoides.
Connell, J.H., 1961b.
of the barnacle Chthamalus stellatus.
the English Channel.
to British 1959.
Ecology, 42: 710-723.
The
distribution
of
intertidal
organisms along the
coast
of
J. Mar. Biol. Ass. U.K., 37: 157-208.
Crisp, D.J. & A.J. Southward, 1959.
Ass. U.K., 37:
EcoL Monogr., 31: 61—104.
The influence of interspecific competition and other factors on the distribution
Crisp, D.J. & A.J. Southward, 1958.
Crisp, D.J. 1958.
J. Mar. Biol. Ass. U.K., 24: 129—183.
Effects of competition, predation by Thais lapillus and other factors on natural
The further spread of Elminius modestus in the British Isles
J. Mar. BioL Ass. UJt, 38: 429-437.
The
spread
of
Elminius
modestus Darwin
in
north-west
Europe.
J. Mar.
Biol.
483-520.
Crisp, D.J. & E. Fischer-Piette, 1959.
Repartition des princippales especes intercotidales de la cote
atlantique francaise en 1954—1955.
Daguzan, J., 1976.
Ann.
Inst. Oceanogr^ Paris, 36: 257-387.
Contribution a 1'ecologie des Littorinidae
ches). 1. Littorina neritoides (L.)
(Mollusques Gasteropodes Prosobran-
et Littorina saxatiiis (Olive).
Cahiers BioL Mar., 17: 213 —
236.
Davy de Virville, A. 1940.
Les zones de vegetation
sur le littoral atlantique.
Soc. Biogeogr.,
7:
295-257.
Den Hartog, C, 1953.
Immigration, disseminaetion and ecology of Elminius modestus Darwin in the
North Sea, specially along the Dutch coast.
Farrell, T.M., 1989.
Beaufortia, 4: 9—20.
Succession in a rocky intertidal community:
and position within a disturbed patch.
Fischer-Piette,, E. 1928.
Recherches de bionomie et d'oceanographie littorales sur la
littoral de La Manche.
Fischer-Piette, E., 1932.
ation des marees.
Ranee
et
le
Ann. Inst Oceanogr. Paris, 5: 201—429.
Repartition des principales especes fixees sur les rochers battus des cotes
et des iles de La Manche, de Lannion a
the importance of disturbance size
Fecamp.
Ann. Inst. Oceanogr., 12: 105—213.
Sur la distribution verticale des organismes fixes dans la zone de fluctu
CJl Ac. ScL, 198: 1721-1723.
Etudes sur la biogeographie intercotidale des duex rives de
la
Manche.
The Linn. Soc. Journ. ZooL, 40: 181-272.
Fischer-Piette, P. & E. Fisher-Piette, 1926.
bionomieque.
Quelques donnees sur l'archipel des Minquier. Apert;u
Bull. Mus. nat. Hist, nat, 32: 107.
Fischer-piette, P. & J.M. Gaillard, 1956.
pennanli Phil.
Gaillard, J.M., 1965.
J. Conchy.
Sur 1'ecologie de Gibbula umblicalis da Costa et Gibbula
Paris, 96: 115—118.
Aspects qualitatifs et quantitatifs de la croissance de la coquille de quelques
Mollusques Prosobranches en fonction de la latitude et des conditions ecologiques.
These Doct.,
Paris.
Gunnill, F.C., 1982.
Effects of plant size and distribution on the numbers of invertebrate species
and individuals inhabiting the brown alga Pelvetia fastigiata.
Mar. BioL, 69: 263—280.
Zonation and Mytiltu Islands on Rocky Intertidal of Dinard
79
Gunnill, F.C., 1983. Seasonal variations in the invertebrate faunas of Pelvelia fastigiata (Fucaceae):
effects of plant size and distribution. Mar. BioL, 73: 115—130.
Haage, P. & B.-O. Jansson, 1970.
1. Quantitative methods.
Hamel, G., 1928.
Quantitative investigations of the Baltic Fucus belt macrofauna.
Ophelia, 8: 187-195.
La repartition des algues a Saint-Malo et dans la Ranee.
Trav. Lab. Saint-Servan,
3: 106-152.
Hamel, G. & R. Lami, 1930.
Liste preliminaire des algues recoltees dans la region
de Saint-Servan.
Trav. Lab. Saint-Servan, 6: 1 — 34.
Harvey, C, 1968.
Distribution and seasonal population changes of Campecopea hinula
Flabellifera).
Hatton, N., 1938.
d'animaux.
(Isopoda:
J. Mar. Biol. Ass. UJt, 48: 761-767.
Essais de bionomie explicative sur quelques especes intercortidales d'algues et
Ann. Inst Oceanogr., 17: 242—348.
Hawkins, S.J., 1983.
Interactions of Patella and macroalgae with setting Semibalanus balanoides.
J.
Exp. Mar. BioL EcoL, 71: 55-72.
Hazlett, A. & R. Seed, 1976.
Lough, County Down.
Herberts, C. 1964.
serratus L.
Hewatt, W.G.,
A study of Fucus spiralis and its associated fauna in Strangford
Proc. R. Ir. Acad. B, 76: 607-618.
Contribution
a
l'etude du peuplement rocheux sessile dans la zone
a
Fucus
Bull. Lab. Marit. Dinard, 49/50: 5-61.
1935.
Ecological
Monterey Bay, California.
Joubin, M. L.t 1929.
succession
in
the
Mylilus californianus habitat
in
Recherches de bionomie marine et d'oceanographie littorales sur la Ranee et
le littoral de la Manche.
L'Hardy, J.P., 1962.
Observations sur le peuplement
Lamouroux en baie de morlaix.
epiphyte
des lames de
Laminaria saccharina
Cah. Biol. Mar., 3: 115—127.
Levings, S.C. & S.D. Garrity, 1983.
Diel and tidal movements in two co-occurring neritid snails:
differences in grazing patterns on a tropical rocky shores.
Lewis, J.R. 1964.
as observed
Ecology, 16: 244—251.
The Ecology of Rocky Shores.
The English Universities Press Ltd., London,
323 pp.
Lubchenco, J., 1983.
Littorina and Fucus: effects of herbivores, substratum heterogeneity and plant
escapes during succession.
MacArthur,
Ecology, 64: 1116—1123.
R.H. & E.O.Wilson, 1972.
The theory of island biogeography.
Princeton
University
Press, Princeton.
Menge B.A. & J.P.Sutherland, 1976.
Species diversity gradients: synthesis of the roles of predation,
competition, and temporal heterogeneity.
Am. Nat, 110: 351 — 369.
Menge, B.A., J. Lubchenco & L.R. Askenas, 1985.
in a tropical rocky intertidal community.
Miller, K.M. & T.H.Carefoot,
1989.
The role of spatial and size refuges in the interaction between
juvenile barnacles and grazing limpets.
Moore, P.G. & R. Seed (eds.), 1985.
D.Sc
The Ecology of Rocky Coasts: essays presented to J.R. Lewis,
Hodder and Stoughton, London, 467 pp.
Newman, W.A. & A. Ross, 1976.
species.
Diversity, heterogeneity and consumer pressure
Oecologia (Berlin), 65: 394—405.
Revision of the balanomorph barnacles: including a catalog of the
Mem. S. Diego Soc. NaL Hist, 9: 1—108.
Norton, T.A., 1976.
Why is Sargassum mulicum so invasive?
Norton, T.A. & R. Fetter, 1981.
and flowing water.
Nunomura, N. 1988.
The
settlement of
J. Mar. Biol. Ass. U.K., 61: 929-940.
Description of Nishimuraia paradoxa gen. et sp. nov., and the first record of
the genus Paracerceis in Japan (Isopoda, Sphaeromatidae).
Paine, R.T., 1966.
Intertidal community structure: experimental studies on the relationship between
a dominant competitor and its principal predator.
R.T., J.C.
Bull. Toyama Sci, Mus., 12: 1—7.
Food web complexity and species diversity. Am. NaL, 100: 65—75.
Paine, R.T., 1974.
Paine,
Br. Phycol. J., 11: 197—198.
Sargassum muticum propagules in stationary
Castillo &
J.
Cancino,
1985.
Oecologia (Berlin), 15: 93—120.
Perturbation and recovery
dominated intertidal assemblages in Chile, New Zealand and Washington.
Panouse, J.B., 1940.
Notes biologique sur les spheromiens.
patterns
of
starfish-
Am. Nat, 125: 679—691.
I. Campecopea hirsute Montagu.
Bull.
80
Soc. Zool. Fr., 65: 93-95.
Plessis, Y., 1961.
Ecologie de l'estran rocheux: etude des biocenose
et recherches experimentales.
Prenant, A., 1923.
Faunule des Lichina pygmaea.
Prenant, M., 1927.
Notes ethologiques sur la faune marine sessile des environs de Roscoff.
iaires, Tuniciers, Anthozoaires.
Retiere, C. & P.
Richoux,
1973.
Bull. Soc. Zool. F, 231-236.
Associations de la faune fixee.
Ecologie
des
polychetes des
Spong
Trav. Slat. Biol. Roscoff, 6: 3—58.
lithoclases
intertidales.
Cak. Biol.
Mar., 14: 39-55.
Richoux, P., 1967.
Ecologie et ethologie de la fauna des fissures intertidales de la region
Malouine.
Travaux de la Section de Biologie Animale et Zoologie, Faculte des Sciences de Lyon, Doctor
these, Universite de Lyon, 78 pp.
Seed, R., 1976.
Ecology, in B.L.Bayne
(ed.)
Marine Mussels: their ecology and physiology: 13 — 65.
Cambridge University Press, Cambridge.
Southward, A.J., 1965.
Life on the Sea-shore.
Southward, A.J., 1976.
On the taxonomic status and distribution of Chthatnalus stellatus (Cirripedia)
Heinemann Educational Books Ltd., London, 153 pp.
in the North-East Atlantic region: with a key to the common intertidal barnacles of Britain.
J.
Mar. Biol. Ass., U.K., 56: 1007-1028.
Stubbings, H.G.
1950.
Earlier records of Elminius
tnodestus Darwin
in
British
waters.
Nature,
Lond., 166: 277-278.
Suchanek,
T.H.,
1979.
The
Mytilus californianus community:studies
organization and dynamics of a mussel bed.
Suchanek, T.H., 1985.
the
composition,
Mussels and their role in structuring rocky shore communities.
P.G. & R. Seed (eds.)
Tsuchiya, M., 1980.
on
structure,
PH.D. thesis, University of Washington, Seattle.
The ecology of rocky coasts.
In,
Moore,
Hodder & Stoughton, London, 70—96.
Biodeposit production by the mussel Mytilus edulis L. on rocky shores. J. Exp.
Mar. Biol. EcoL, 47: 203-222.
Tsuchiya, M., 1982.
Catching of organic matter by the
mussel
Mylilus edulis L.
Bull. Mar. Biol.
Stn. Asamuski, Tohoku Univ., 17: 99-107.
Tsuchiya, M., 1984.
Effect of barnacle cover on the distribution of the limpet Collisella (Conoidac-
mea) heroldi (Dunker) and the periwinkle Littorina brevicula (Philippi)
zone.
Tsuchiya, M. & M. Nishihira, 1985.
Islands of Mytilus as a
island size on community structure.
Tsuchiya,
on the higher eulittoral
Bull. Mar. Biol. Stn. Asamuski, Tohoku Univ., 17: 177—189.
M. &
M. Nishihira,
1986.
habitat
for small animals: effect of
Mar. Ecol. Prog. Sen, 25: 101 — 111.
Islands of Mytilus edulis as a
habitat
for small
intertidal
animals: effect of Mytilus age structure on the species composition of the associated fauna and
community organization.
Mar. Ecol. Prog. Ser., 31: 171 — 178.
Tsuchiya, M. & D. Bellan-Santini, 1989.
community structure
France.
of mussel
Vertical distribution of shallow rocky shore organisms and
beds
(Mytilus galloprovincialis)
along the
coast
of
Marseille,
Mesogee, 49: 91-110.
Tsuchiya, M., Y. Nakasone & M. Nishihira, 1986.
Community structure of coral associated inverte
brates of the hermatypic coral, Pavona frondifera, in the Gulf of Thailand.
Tsuchiya, M., Y. Nakasone & M. Nishihira, 1989a.
Galaxea, 5: 129—140.
Species composition of small animals associated
with the coral Pocillopora datnicornis at Sichang Islands, the Gulf of Thailand:
coral colony.
Size effect of
Galaxea, 8: 257-269.
Tsuchiya, M., M. Nishihira, S. Choohabandit & S. Poung-In,
1989b.
Environmental heterogeneity
created by the spatangoid urchin Brissus latecarinatus and its effect on sandy bottom communities
in the Gulf of Thailand.
Underwood, A.J., 1977.
Galaxea, 8: 241-255.
Movements of intertidal gastropods.
Underwood, A.J. & M.G.Chapman, 1985.
J. Exp. mar. Biol. Ecol., 26: 191—201.
Multifactorial analyses of directions of movement of animals.
J. Exp. Mar. Biol. EcoL, 91: 17-43.
Underwood, A.J. & M.G.Chapman, 1989.
Experimental analyses of the influences of topography of
the substratum on movements and density of an intertidal snail, Littorina unifasciata.
J. Exp. Mar.
Biol. EcoL, 134: 175-196.
Vaillant, L., 1870.
Observations faites a
Saint-Malo sur led zones littorales superieures.
Bull
81
Soc. Philomath, Paris, 7.
Wieser, W., 1963. Adaptations of two intertidal isopods. II. Comparison between Campecopea hirsuta
and Naesa bidentata (Sphaeromatidae). J. Mar. Biol. Ass. U.K., 43: 97—112.
Wolf, W.J. & A.J.J. Sandee,
1971.
Distribution and ecology of the
estuarine area of the Rivers Rhine, Meuse, and Scheldt.
Wood, V. & R. Seed, 1980.
Decapoda Reptantea of the
Netherland J. Sea Res., 5: 197—226.
The effects of shore level on the epifaunal communities associated
with Fucus serratus (L.) in the Menai Strait, North Wales.
Cah. Biol. Mar., 21: 135-154.
Resume
Dans le cadre de l'etude de la structure de la communaute d'animaux de petite taille associes a la
mouliere a Mytilus edulis des cotes de la region de Dinard, la distribution verticale des organismes
intertidaux de substrat dur a
ete analysee.
En termes generaux leurs modalites de repaartition sont
identiques a celles reconnues, de longue date, sur les cdtesde la Manche et de I'Atlantique.
Cependant,
dans ce secteur, caracterise par des marees de tres forte amplitude I'originalite de la zonation reside
en un development vertical des ceintures vegetales (et des peuplements animaux
succedent depuis la zone des lichens jusqu'd celle des laminaires.
infeades)
qui
se
Pour leur part, les balanes Chtha
malus montagui et Balanus balanoides occupent une large zone dont 1'extension verticale est de l'ordre
de 6 a 10 m; 1'espece Elminius modestus, recemment introduite, est egalement commuce et relativement
abondante en mode abrite.
La succession verticale des differentes especes de Patelles et de Gibbules
est particulierrement bien marquee.
L'abondance des moules Mytilus edulis varie considerablement
d'unsite a l'autre mais aussi a tres petite echelle d'espace.
La structure de la communaute des petits animaux associes a des agregats de taille variee de
Mytilus edulis ("ilots a Mytilus) a ete analysee a deux niveaux bathymetriques et des differences dans
la composition faunistiques ont ete mises en evidence.
Aux deux niveaux la richesse specifique et le
nombre d'individus s'accroit avec
l'agregat
la
dimension
d'especes/surface de l'agregat) diminue.
de la
mais la densite specifique (nombre
D'un autre cate la densite absolue (nombre d'individus/'
surface de 1'agregat) reste relativement constante et independante de la taille de l'agregat; ceci est
du a la forte abondance de petites balanes telles Chthamalus montagui, Balanus balanoides et Elminius
modestus fixees sur les coquilles de moules et du mollusque bivalve Lasaea rubra.
site specifique (H')
decroit.
espece"
Alors que la diver-
ne montre aucune tendance en liaison avec taille de l'agregat, l'equitabilite (J')
La structure du peuplement des "Hot a Mytilus" est discutee en terme de relation "aireet
soulignees.
les
repercussions des
caracteristiques micro-spatiales
sur
la
diversity specifique sont

Bulletin of the College of Science, University of the Ryukyus

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