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Bougrier S, Geairon P, Deslous-Paoli J, Bacher C, Jonquières G.. Allometric relationships and effects of temperature on clearance and oxygen consumption rates of Crassostrea gigas (Thunberg). Aquaculture 134: 143-154

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Abstract

Clearance and oxygen consumption rates of Crassostrea gigas were investigated with animals of 5–200 g total wet weight (0.1–3 g dry tissue weight), and at different temperatures (5–32 °C) after 10 days acclimation. During this period significant mortalities were observed at 32 °C, which may be close to the upper thermal limit for this species. For each temperature, allometric relationships between physiological rates and the dry weight (DW, g) of the animal were estimated. Clearance rate (CR, 1·h−1) was maximal at 19 °C; oxygen consumption rate (VO2, mgO2·h−1) increased over the range of experimental temperatures (T, °C). Two statistical models are proposed: CR = [a − (b ∗ (T − c) 2)] ∗ DWd and . However, neither model is appropriate during the reproductive period.
Aquaculture
ELSEVIER Aquaculture 134 (1995) 143-154
Allometric relationships and effects of temperature
on clearance and oxygen consumption rates of
Crassostrea gigas (Thunberg)
S. Bougrier ‘**, P. Geairon, J.M. Deslous-Paoli 2, C. Bather 3,
G. Jonquikres 4
IFREMER, LABElM, BP 133.17390 La Tremblade. France
Accepted 22 February 1995
Abstract
Clearance and oxygen consumption rates of Crassosfrea gigas were investigated with animals of
5-200 g total wet weight (0.1-3 g dry tissue weight), and at different temperatures (5--32”(Z) after
10 days acclimation. During this period significant mortalities were observed at 32”C, which may be
close to the upper thermal limit for this species. For each temperature, allometric relationships between
physiological rates and the dry weight (DW, g) of the animal were estimated. Clearance rate (CR,
1. h-l) was maximal at 19°C; oxygen consumption rate (VO*, mg Oz. h-‘) increased over the range
of experimental temperatures (T, “C). Two statistical models are proposed: CR= [a - (b * (T-
c) *) ] * DWd and VO1 = [a + (b * cT) ] * DWd. However, neither model is appropriate during the
reproductive period.
Keywords: Clearance rate; Oxygen; Allometry; Temperature; Crassostrea gigas
1. Introduction
Studies of bivalve ecosystem dynamics require an understanding of the trophic structure
of the productive area, the stocks of natural and cultivated molluscs and their impact on the
nutritional potentialities of the system. Modelling of such dynamics requires linked physical
* Corresponding author. Present addresses:
CNRS-IFREMER, CREMA, BP 5, 17137 L’Houmeau, France.
* IFREMER, DEL, I Rue Jean VILAR, 34200 S&e, France.
IFREMER, MERHA. BP 1049.44037 Nantes C&lex 01, France.
4 IFREMER, COP, BP 7004, TARAVAO, Tahiti, French Polynesia.
0044-8486/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved
SSDIOO44-8486(95)00036-4
144 S. Bougrier et al. /Aquaculrure I34 (1995) 143-154
and biological approaches. The relevant biological models are often based upon consider-
ation of the animal’s energetics, related to fluctuations in the biotic and abiotic conditions
within the water column. An understanding of food acquisition (i.e. clearance rate) and
metabolic loss (i.e. oxygen consumption rate) is therefore essential. These indices of energy
acquisition and energy loss would define the minimum needs for growth, and are therefore
critical to choosing potential cultivation areas. These physiological functions, when inte-
grated into an ecosystem model, would allow predictive modelling of shellfish production
of a bay.
Clearance and oxygen consumption rates are dependent on both exogenous and endog-
enous factors (Percy et al., 1971; Winter, 1973; Foster-Smith, 1975; Schulte, 1975; Shum-
way, 1982; Shumway and Koehn, 1982; Gerdes 1983a, b; Fiala-M&.lioni et al., 1985).
Studies (Bayne and Newell, 1983) have shown that size and temperature are two important
factors determining energy balance. The aim of this study was to establish statistical descrip-
tions of clearance and oxygen consumption rates of Crassostrea gigas related to two factors:
dry weight and temperature.
2. Materials and methods
C. gigas of 5-200 g total wet weight were collected from the Marennes-Oleron basin
(Fig. 1) in September 1988, February 1989 and September 1990. Natural temperatures and
salinities at the time of collection were 16°C and 32%0 ( 1988)) 6°C and 30%0 ( 1989)) and
23°C and 35%0 ( 1990), respectively.
In 1988 and 1989, animals were acclimated in the laboratory to the following tempera-
tures: 5, 10, 15, 20 and 25”C, which are representative of the thermal cycle of the basin. In
1990, animals were acclimated to higher temperatures (20, 23, 26, 29 and 32”C), which
are representative of the summer temperatures in the holding ponds (Marennes-O&on) or
of the French Mediterranean coast.
‘For each experimental temperature, 38 oysters were maintained in 3 tanks of 20 litres of
1 pm filtered seawater. Each day, 10 litres was changed, and the waste material was removed
from the tank. The temperature and salinity were measured twice a day. Each day, a mixture
of 12.5 ml (concentration of 4. 106. ml- ‘) of Zsochrysis galbana (Tahititian close T. Iso)
and 8.3 ml (concentration of 6. 106. ml- ‘) of Chaetoceros calcitrans (in September 1988),
25 ml of T. Iso (February 1989), and 125 ml of T. Iso (September 1990) was added per
oyster. The rate of change from the initial temperature to the experimental temperatures
was 1°C per day (0.5”C a.m. and 0.5”C p.m.). Feeding was stopped 1 day prior to each
measurement as suggested by Weigert (1968). Animals were thus acclimated for 10 days
to stabilized experimental temperature, but fed for only 9 days.
Significant mortalities occurred at 32°C in September 1990, with only 17 oysters surviving
at the end of the acclimation period.
Individual dry tissue weight was measured after freeze-drying for 72 h.
Individual clearance rates were estimated by measuring the consumption of algae, added
to 0.22 pm filtered seawater in a flow-through system as described (Anonymous, 1987) :
CR= [(Z-@/Z] *F
S. Bougrieret al. /Aquaculture 134 (1995) 143-154 145
Fig. 1. The Marennes-Ol&on basin.
where I and 0 are, respectively, the algal concentration of the inflow (measured at the exit
of a sedimentation control tank) and outflow, and F (1. h- ‘) is the flow inside the meas-
urement chamber. Algal concentrations were estimated by using a Multisizer (Coulter,
Coultronics, Margency, France).
The rate of oxygen consumption was measured in a closed chamber of 500 or loo0 ml,
according to the size of each animal. These chambers contained 0.22 pm filtered seawater,
without addition of food. Salinities were natural salinities: 32% ( 1988), 30% ( 1989) or
35% ( 1990). Oxygen consumption was estimated as the rate of decrease of oxygen con-
centration inside the measurement chamber, as recorded by oxymeter probes (Orbsiphere
Laboratories, Orbisphere France, Maurepas, France).
Linear regression was used to describe the allometric relationship. Temperature and
season effects were tested with a two-factor ANOVA analysis. Non-linear regression was
used to establish statistical models:
CR={U--[~*(T-C)~]}*DW~
V02= [a+(b*cr)] *DWd
where CR (1. h-‘) is the clearance rate, VOZ (mg 0,. h-‘) is the oxygen consumption, T
(“C) is the temperature, DW (g) is the dry tissue weight and a, b, c, d are constants.
146 S. Bougrier et al. /Aquaculture 134 (1995) 143-154
3. Results
Allometric relationships with body size were established for each temperature and for
each experimental period (Tables 1 and 2). An exponent value of b < 1 was confirmed for
this species. The intercepts, or a values, representing clearance rates of an animal with 1 g
dry tissue weight, increased with temperature from 5°C (2.0 1. h- ‘) to 20°C (4.8 1. hh ‘),
and then decreased to 32°C (2.5 1. h- ) . No significant difference (P > 0.05) was observed
between November 1988 and February 1989, suggesting that for a given temperature, the
season, outside of the reproductive period, had no effect on the clearance rate of the animal.
On the other hand, the effect of temperature was significant (P < 0.05).
Rates of oxygen consumption increased significantly with temperature from 5°C (0.2 mg
0,. hh’) to 32°C ( 1.9 mg 0,-h-‘). However, the changes in a values with increases in
temperature were different between seasons (P < 0.05). When the experimental tempera-
tures were lower than natural initial temperature, values decreased in an irregular way. In
September, an increase in oxygen consumption was observed between lO-15°C and 20-
25’C, meanwhile values were similar for 5°C and lo’%, and for 15°C and 20°C. On the
other hand, a change to a higher temperature than the initial (February 1989 and September
1990)) induced a gradual increase in the rate of oxygen consumption.
Descriptive statistical models of clearance rate (Fig. 2) and oxygen consumption (Fig.
3) for C. gigas related to dry tissue weight and temperature were estimated from non-linear
regression analysis:
CR= [a- (b* (T-c)‘)] *DWd,
with a=4.825 f0.089, b=0.013 +O.OOl, c= 18.954kO.396, d=0.439f0.030, n=328,
?=0.567;
Table 1
Allometric relationships for clearance rate (CR = aW b, for different temperatures ( T) and seasons in C. gigas
Seasons T a b n r
September 1988 5 2.170
10 3.903
15 4.921
20 4.281
25 4.649
February 1989 5 2.014
10 3.575
15 4.133
20 4.852
25 4.432
September 1990 20 3.365
23 4.507
26 4.442
29 3.131
32 2.570
0.364 28 0.669 l
0.311 28 0.609 l
0.535 28 0.726’
0.326 28 0.505 *
0.640 21 0.888’
0.348 12 0.321
0.539 26 0.621.
0.312 29 0.540’
0.695 32 0.736’
0.190 22 0.577 *
0.707 12 0.595 *
0.422 13 0.595’
0.670 20 0.753’
0.663 16 0.514’
0.585 13 0.693 *
n = number of animals, r = correlation coefficient.
*Significant (P < 0.05) ANOVA for the model.
S. Bougrieret al. /Aquaculture 134 (1995) 143-154 147
Table 2
Allometric relationships for oxygen consumption ( VOz = a W b, for different temperatures ( T) and seasons in C.
gigas
Seasons T a b n r
September 1988
February 1989
September 1990
5
10
15
20
25
5
10
15
20
25
20
23
26
29
32
0.422
0.448
0.868
0.860
1.288
0.189
0.344
0.851
1.119
1.077
1.123
1.413
1.741
1.931
0.771 19 0.827’
0.823 30 0.871’
0.775 30 0.943’
0.945 27 0.901 l
0.865 26 0.957’
0.546 20 0.717’
0.949 32 0.845 *
0.715 26 0.741.
0.605 35 0.812’
0.905 35 0.875 *
0.811 22 0.870’
0.576 23 0.822’
0.863 23 0.858’
0.811 17 0.797 *
0.693 10 0.816’
n = number of animals, r = correlation coefficient.
‘Significant (P<O.O5) ANOVA for the model.
o 0 ! 1 1 I I I 1
I I I I I I 1
o 1 2 3 4 5 6 7 8
Predicted clearance rate (lb’)
Fig. 2. Predicted and observed clearance rates for C. gigas (observations = predictions is represented by the line).
VO,= [a+ (b*?)] *DWd,
witha= -0.432+0.219, b=0.613f0.200,c=1.042_+0.007,d=0.800f0.029,n=380,
?=0.768.
A 3-D representation of these models is given in Figs. 4 and 5.
148 S. Bougrieret nl. /Aquaculture 134 (199s) 143-154
3.0
‘:
G
k
0,z.s
5
*j 2.0
f
2 1.5
v
%
em
@LO
B
E
p 0.5
8
0.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0
Predicted oxygen consumption (mg Or-h-‘)
Fig. 3. Predicted and observed oxygen consumption rates for C. &a~ (observations = predictions is represented
by the line).
Fig. 4.3-Drepresentationofclearancerate model for C. gigas: CR= 14.825 - (0.013* CT- 18.954)‘) 1 * JIWO.~~‘.
S. Bougrier et al. /Aquaculture 134 (1995) 143-154 149
Fig. 5.3-D representation of oxygen consumption rate model for C. gigas:
VOz = [ - 0.432 + (0.613 + 1.042=) ] * Dw800.
4. Discussion
Rates of clearance and oxygen consumption for C. gigas were related to dry tissue weight,
by allometric relationships. In bivalve molluscs, these relationships are usually characterized
by an allometric coefficient less than unity, indicating that animals of small size filter and
consume oxygen proportionally more than animals of larger size. This may be explained
( 1) by a surface/mass exchange relationship [indeed, Hughes ( 1969) reported filtration
rates to the gill area, and Foster-Smith ( 1975, 1976 to total gill ostial area] ; (2) by the
difference of growth rates during the life of the animal. Hamburger et al. (1983) showed
b-values of oxygen consumption similar for the pelagic larval and juvenile stages, but
different for the adult. In fact, in C. gigas, in the first year energy needs are solely allocated
to somatic growth of the animal (Deslous-Paoli and H&al, 1988). Later, metabolism is
mainly directed to gamete maturation and spawning (Rodhouse, 1978; Bayne and Newell,
1983). The reproductive effort is responsible for an 18% energy loss for yearling oysters,
and about 63% during the second year (Deslous-Paoli and Heral, 1988).
The rates of both clearance and oxygen consumption depend on seawater temperature.
Clearance rates increased when the temperature increased up to a maximum of 19°C beyond
which the clearance rate decreased. On the other hand, oxygen consumption increased over
the entire range of temperatures tested.
Two types of response to changes of temperature have been described in the literature
for variously acclimated or experimentally treated bivalves. A gradual increase of clearance
rate with temperature has been noted by Walne ( 1972) in Mytilus edulis, by Walne ( 1972))
150 S. Bougrier et al. /Aquaculture 134 (1995) 143-154
Rodhouse ( 1978) and Hutchinson and Hawkins ( 1992) in Ostrea edulis, by Walne ( 1972),
Bernard ( 1974) and Kusuki ( 1978) in C. gigas, and for oxygen consumption by Widdows
(1973) in M. edulis, by Newell et al. (1977) and Rodhouse ( 1978) in 0. edulis, by Dame
(1972) in C. uirginicu, and by Bernard (1974) and Kim (1980) in C. gigas. The second
type of response is an increase of these functions to an optimum of temperature: Schulte
( 1975) and Widdows (1978) in M. edulis, Goulletquer et al. ( 1989) in Ruditupes philip-
pinurum, Newell et al. (1977) in C. virginicu, Le Gall and Raillard ( 1988) in C. gigus for
clearance rate, and Hutchinson and Hawkins ( 1992) in M. edulis, Goulletquer et al. ( 1989)
in R. philippinurum, Le Gall and Raillard ( 1988) in C. gigus, for oxygen consumption.
M. edulis and C. gigus results seem to be confused. This may be explained by: ( 1) Some
studies are based on natural acclimation, others on experimental acclimation for various
duration. Moreover, Widdows ( 1976) showed that immediate, short or long acclimation
induced different responses by mussels according to the natural thermal variations of the
rearing area. (2) The range of temperature in most of the studies quoted was insufficient to
show a possible optimum of temperature; the maximum tested in Walne ( 1972) was 2O”C,
which is the optimum for C. gigus in the results reported here.
Raillard et al. ( 1993) established a model of clearance rate for C. gigus, as a function of
dry tissue weight and seston load. Doering and Oviatt ( 1986) described for Merceruzriu
mercenariu a model combining temperature and length of the animal. Rodhouse ( 1978)
presented a model combining the dry tissue weight and temperature effects after a 6 days
acclimation in 0. edulis
In the model proposed here, the u-parameter (4.8) represents the clearance rate of an
individual of 1 g dry tissue weight at an optimum temperature of 19°C (c-parameter). The
relatively large b-value (0.013) shows the concavity of the symmetric curve, due to marked
parabolic effects of temperature ( [ T- c] *) , above and below the optimum c-value which
caused the maximal clearance rate. This value of approximately 19°C is considered to be
the minimal critical temperature inducing spawning in C. gigus (Gras et al., 197 1) . The d-
parameter represents the allometric coefficient related to dry tissue weight. Its value of
0.439 is similar to that reported for other bivalves (Thompson and Bayne, 1974; Schulte,
1975; Rodhouse, 1978; Widdows, 1978).
Concerning oxygen consumption related to dry tissue weight and temperature, twomodels
have been proposed in the literature: a linear model (Dame, 1972) for C. virginicu, and a
model for C. gigus (Kim, 1980)) in which the allometric coefficient was a function of
temperature. However, this latter model predicted higher oxygen consumption than is
observed in the Marennes-Ol&on basin, especially for high temperatures (Fig. 6). More-
over, in Kim’s study the effect of dry tissue weight seemed to be of little importance,
contrary to what is normally accepted.
The difference in oxygen consumption rates by the oysters in this study caused by changes
of temperature indicates that 10 days of acclimation was probably not enough to regulate
their metabolism. These differences may be related to the effect of temperature on the rate
of enzymatic activity involved in normal metabolism. Indeed, from an initial situation of
low enzyme activity (low metabolism in February at 6”C), the increased enzymatic activity
would be synchronous with the increase of temperature. On the other hand, when the activity
was high (September 1988), a decline of temperature would not induce immediate depres-
sion of enzymatic activity. However, observed oxygen consumption obtained in the field in
S. Bougrieret al. /Aquaculture 134 (1995) 143-154 151
-A-KOSg
+Klg
+K2g
-.- 0.5 g
‘--lg
,-f2g
A-
5 8 11 14 17 20 23 26 29 32
Temperature (“C)
Fig. 6. Oxygen consumption model rate for C. gigas proposed here, and that of Kim (1980) for 3 values of dry
weight.
natural acclimated oysters is in agreement with the model proposed here, based on experi-
mental acclimated animals (Bougrier, unpublished data).
In contrast, a model based on animals acclimated to temperatures higher than the initial
temperature was very similar to that obtained with all the animals. The model reported here
can be written: VOz = [a + be’“‘*] DWd. The natural logarithm (In) of c is analogous to the
QIO, which often indicates a doubling in metabolic rate for every 10°C rise in temperature.
In such a model, oxygen consumption is divided into two terms: aDWd + be’“cTDWd. Only
the second term is a function of temperature, doubling at 18°C. This value is close to the
temperature ( 19°C) inducing the maximal clearance rate. The term a + b indicates the
oxygen consumption rate for a 1 g dry tissue weight oyster at 0°C ( VOz = 0.18 mg . h- ) .
The d-parameter is the allometric coefficient. Its value of 0.8 is similar to that generally
reported for bivalves (Bayne and Newell, 1983).
In aquaculture, the areas for rearing are chosen based on the nutritional potential of the
system and the energy needs of the animals. A knowledge of the physiological functions of
food acquisition and metabolic loss could provide information, although incomplete, on the
probable success of rearing such species in that area. The surface response of the ratio of
oxygen consumption/ingestion, expressed in term of energy, for different diets can give
such information. Indeed, assimilated energy should represent about 80% of the ingested
energy (Thompson and Bayne, 1974; Winter, 1978). It means that for no net production,
at which catabolism (loss of energy = respiration = oxygen consumption) and anabolism
(tissue acquisition of energy = assimilation = 0.8 *ingestion) are equal, the ratio, in terms
of energy, oxygen consumption/ingestion (VO,/I) would be 0.8. In that case, the energy
needs for a 1 g dry weight oyster, at no net production and under the pseudofaeces threshold
hypothesis (ingestion = clearance rate * food availability), were about 3 J. l- for 5°C
and 13 J. l-‘, nearly 4 times greater, for 32°C (Fig. 7). Thus, the animal will grow (Fig.
8, white area, VO,/I < 0.7), survive (Fig. 8, black area, 0.8 < VOz/I > 0.7) or die (Fig. 8,
grey area, VO,/I > 0.8) depending on the combined effect of temperature and food avail-
ability, as did half of the oysters during the 32°C acclimation experiment. This temperature
S. Bougrier et al. /Aquaculture 134 (1995) 143-154
8.00 -;
z
Fig. 7. Relationship of clearance rate, oxygen consumption (circles) and necessary diet (squares) for no net
production (VO& = 0.8; see text) for a 1 g dry tissue weight C. gigas related to temperature (5-32°C).
19
17
15
13
11
9
7
5
3
1
5 7 9 11 13 15 17 19 21 23 25 27 29 31
Tempemture (“C)
Fig. 8. Values of the ratio VO,/l, (0.1-1.2) for a 1 g dry tissue weight C. gigas for different temperatures and
food availabilities.
would be the upper thermal limit for C. gigas, confirming the observations of Le Gall and
Raillard ( 1988) who estimated it at 30°C.
Relationships reported here are for animals outside of their reproductive period. The
models are probably not applicable during the reproductive period. Bensch et al. ( 1991),
modelling the growth of R. philippinurum in an experimental system, could not relate their
S. Bougrier et al. /Aquaculture 134 (1995) 143-154 153
results to data collected just after spawning. Deslous-Paoli et al. ( 1987) reported an increase
in the clearance rate during the period of gamete maturation. On the other hand, lower
values for oxygen consumption and clearance rates than predicted by the model were
observed at the end of gamete maruration (Soletchnik, personal communication).
Acknowledgements
The authors are indebted to Drs. Brian L. Bayne, David J. Wildish, two anonymous
reviewers and the Editor, Robert P. Wilson, for their criticism, suggestions and aid in
translation.
References
Anonymous, 1987. Bilan Bnergetique chez les mollusques bivalves. Groupe de travail, La Tremblade, 1987. Vie
mar., H.S. 7: I-68.
Bayne, B.L. and Newell, R.C., 1983. Physiological energetics of marine molluscs. In: K.M. Wilburg and A.S.M.
Saleuddin (Editors), The Mollusca, Vol. 4. Academic Press, London, pp. 407-515.
Bensch, A., Bacher,C., Baud,J.P.and Martin, J.L., 1991. Modelisationdelacroissancede Ruditapesphilippinarum
dans un systeme expCrimenta1. In: Aspects recents de la Biologie des Mollusques. Actes de Colloques, Vol.
13, IFREMER, pp. 71-82.
Bernard, F-R., 1974. Annual biodeposition and gross energy budget of mature pacific oyster, C. gigas. J. Fish.
Res. Board Can., 31: 185-190.
Dame, RF, 1972. The ecological energies of growth, respiration and assimilation in the intertidal American oyster
Crassosrrea virginica. Mar. Biol., 17: 243-250.
Deslous-Paoli, J.M. and H&al, M., 1988. Biochemical composition and energy value of Crassosrren gigas
(Thunberg) cultured in the bay of Marennes-Oleron. Aquat. Living Resour., 1: 239-249.
Deslous-Paoli, J.M., H&al, M., Goulletquer, P., Boromthanarat, W., Razet, D., Gamier, J., Prou, J. and Barille,
L., 1987. Evolution saisonniere de la filtration de bivalves intertidaux dans des conditions naturelles. Ocktnis,
13: 575-579.
Doering, P.H. and Oviatt, C.A., 1986. Application of filtration rate models to field populations of bivalves: an
assessment using experimental mesocosms. Mar. Ecol. Prog. Ser., 31: 265-275.
Fiala-M&Iioni, A., Copello, M. and Colomines, J.C., 1985. Relations trophiques entre l’huitre Crawxtrea gigas
et son milieu: influence de la concentration et de la taille des particules. In: Bases biologiques de 1’Aquaculture.
Actes de Colloques, Vol. 1, IFREMER, pp. 64-75.
Foster-Smith, R.L., 1975. The effect of concentration of suspension on the filtration rate and pseudo-faecal
production for Mytilus edulis L., Cerastoderma edule L. and Venerupis pullastra. J. Exp. Mar. Ecol., 17: l-
22.
Foster-Smith, R.L., 1976. Some mechanisms for the control of pumping activity in bivalves. Mar. Behav. Physiol.,
4: 41-60.
Gerdes, D., 1983a. The Pacific oyster Crassosfrea gigas. 1. Feeding behaviour of larvae and adults. Aquaculture,
31: 195-219.
Gerdes, D., 1983b. The Pacific oyster Crassostreagigus. II. Oxygen consumption of larvae and adults. Aquaculture,
31: 221-231.
Goulletquer, P., H&al, M., Deslous-Paoli, J.M., Prou, J., Gamier, J., Razet, D. and Boromthanarat, W., 1989.
Ecophysiologie et bilan Bnergetique de la palourde japonaise d’elevage Ruditapesphilippinarum. J. Exp. Mar.
Biol. Ecol., 132: 85-108.
Gras, P., Comps, M., David, A. and Baron, G., 1971. Observations preliminaires sur la reproduction des huitres
dans le bassin de Marennes en 1971. Sci. PI?ches, Bull. Inst. PEches Mar., 207: 1-16.
154 S. Bougrier et al. /Aquaculture 134 (1995) 143-154
Hamburger, K., Mohlenberg, F., Randlov, A. and Riisgard, H.U., 1983. Size, oxygen consumption and growth in
the mussel Mytilus edulis. Mar. Biol., 75: 303-306.
Hughes, R.N., 1969. A study of feeding in Scrobicukzriaplana. J. Mar. Biol. Assoc. UK, 49: 805-823.
Hutchinson, S. and Hawkins, L.E., 1992. Quantification of the physiological responses of the European flat oyster
Ostrea edulis L. to temperature and salinity. J. Moll. Stud., 58: 215-226.
Kim, Y.S., 1980. Efficiency of energy transfer by a population of the farmed Pacific oyster Crassostrea gigas in
Geoje-Hansan bay. Bull. Korean Fish. Sot., 13: 179-193.
Kusuki, Y., 1978. Relationship between quantities of faecal material produced and of the suspended matter removed
by the Japanese oyster. Bull. Jpn. Sot. Sci. Fish., 44: 1183-l 185.
Le Gall, J.L. and Raillard, 0.. 1988. Influence de la temperature sur la physiologie de l’huitre Crassostrea gigas.
Ckeanis, 14: 603-608.
Newell, I.E., Johnson, L.G. and Kofoed, L.H., 1977. Adjustment of the components ofenergy balance in response
to temperature change in Ostrea edulis. Gecologia, 30: 97-l 10.
Percy, J.A., Aldrich, F.A. and Marcus, T.R., 1971. Influence of environmental factors on respiration of excised
tissues of American oysters, Crassostrea uirginica. Can. J. Zool., 49: 353-360.
Raillard, 0.. Deslous-Paoli, J.M., H&al, M. and Razet, D., 1993. Modelisation du comportement nutritionel et de
la croissance de l’hu&re japonaise Crassostrea gigas. Oceanol. Acta, 16: 73-82.
Rodhouse, P.G., 1978. Energy transformation by the oyster Ostrea edulis in a temperate estuary. J. Exp. Mar.
Biol. Ecol., 34: 1-22.
Schulte, E.H., 1975. Influence of algal concentration and temperature on the filtration rate of Myths edulis. Mar.
Biol., 30: 331-341.
Shumway, S.E., 1982. Oxygen consumption in oysters: an overview. Mar. Biol. Lett., 3: l-23.
Shumway, S.E. and Koehn, R.K., 1982. Oxygen consumption of the American oyster Crassostrea oirginica. Mar.
Ecol. Prog. Ser., 9: 5968.
Thompson, R.J. and Bayne, B.L., 1974. Some relationships between growth, metabolism and food in the mussel
Myths edulis. Mar. Biol., 27: 317-326.
Walne, P.R., 1972. The influence of current speed, body size and water temperatures on the filtration rate of five
species of bivalves. J. Mar. Biol. Assoc. UK, 52: 345-374.
Weigert, R.G., 1968. Thermodynamic considerations in animal nutrition. Am. Zool., 8: 71-374.
Widdows, J., 1973. Effect of temperature and food on the heart beat, ventilation rate and oxygen uptake of Myths
edulis. Mar. Biol., 20: 269-276.
Widdows, J., 1976. Physiological adaptation of Myths edulis to cyclic temperature. J. Comp. Physiol., 105: 115-
128.
Widdows, J., 1978. Combined effect of body size, food concentration and season on the physiology of Myths
edulis. J. Mar. Biol. Assoc. UK, 58: 109-124.
Winter, J.E., 1973. The filtration of Myths edulis and its dependence on algal concentration measured by a
continuous automatic recording apparatus. Mar. Biol., 22: 317-328.
Winter, J.E., 1978. A review on the knowledge of suspension feeding in lamellibranchiate bivalves with special
reference to artificial aquaculture systems. Aquaculture, 1: 1-13.
... The function can vary among oyster species (23,24,33). For example, Crassostrea virginica reaches its highest filtration rate at around 27°C (24), while Crassostrea gigas reaches its highest rate at a lower temperature of around 19°C (34). ...
... In this particular experiment, it may be reasonably assumed that the shedding fraction, « o , for OsHV-1 during filter-out/shedding processes is close to « o for group 2 viruses (e.g., NoV and TV), that is, on the order of 0.1 day 21 (Table 1), and therefore, the two components of the removal rate, c and « o f/s , are assumed to be 4.2 day 21 and 0.3 day 21 at 22°C, respectively. The response of the filtration rate (f) for C. gigas to temperature follows the measurement reported previously by Bougrier et al. (34), and the effect of temperature on the metabolic rates of oysters is assumed to be equal to the reported effect of temperature on the oxygen consumption rate of oysters (34), which leads to a Q 10 temperature coefficient of 1.5, where Q 10 describes the factor by which the rate changes with a temperature increase of 10°C. Higher water temperatures are thought to promote more rapid viral replication and higher mortality rates of infected oysters (63), and mathematically, this indicates that a higher temperature may correspond to a higher initial rate of virus replication (u p 9 0 ) in the transformed model. ...
... In this particular experiment, it may be reasonably assumed that the shedding fraction, « o , for OsHV-1 during filter-out/shedding processes is close to « o for group 2 viruses (e.g., NoV and TV), that is, on the order of 0.1 day 21 (Table 1), and therefore, the two components of the removal rate, c and « o f/s , are assumed to be 4.2 day 21 and 0.3 day 21 at 22°C, respectively. The response of the filtration rate (f) for C. gigas to temperature follows the measurement reported previously by Bougrier et al. (34), and the effect of temperature on the metabolic rates of oysters is assumed to be equal to the reported effect of temperature on the oxygen consumption rate of oysters (34), which leads to a Q 10 temperature coefficient of 1.5, where Q 10 describes the factor by which the rate changes with a temperature increase of 10°C. Higher water temperatures are thought to promote more rapid viral replication and higher mortality rates of infected oysters (63), and mathematically, this indicates that a higher temperature may correspond to a higher initial rate of virus replication (u p 9 0 ) in the transformed model. ...
Article
Full-text available
Contamination of oysters with a variety of viruses is one key pathway to trigger outbreaks of massive oyster mortality as well as human illnesses, including gastroenteritis and hepatitis. Much effort has gone into examining the fate of viruses in contaminated oysters, yet the current state of knowledge of nonlinear virus-oyster interactions is not comprehensive because most studies have focused on a limited number of processes under a narrow range of experimental conditions. A framework is needed for describing the complex nonlinear virus-oyster interactions. Here, we introduce a mathematical model that includes key processes for viral dynamics in oysters, such as oyster filtration, viral replication, the antiviral immune response, apoptosis, autophagy, and selective accumulation. We evaluate the model performance for two groups of viruses, those that replicate in oysters (e.g., ostreid herpesvirus) and those that do not (e.g., norovirus), and show that this model simulates well the viral dynamics in oysters for both groups. The model analytically explains experimental findings and predicts how changes in different physiological processes and environmental conditions nonlinearly affect in-host viral dynamics, for example, that oysters at higher temperatures may be more resistant to infection by ostreid herpesvirus. It also provides new insight into food treatment for controlling outbreaks, for example, that depuration for reducing norovirus levels is more effective in environments where oyster filtration rates are higher. This study provides the foundation of a modeling framework to guide future experiments and numerical modeling for better prediction and management of outbreaks.
... The increased feeding rates that occur to offset the metabolic cost allow animals to maintain a positive energy balance (i.e., SFG) across environmental conditions (Wilbur and Hilbish, 1989;Sarà et al., 2008;Kang et al., 2016). A lack of such compensation processes may induce a negative energy balance under unfavorable conditions (Bayne and Newell, 1983;Bougrier et al., 1995). Therefore, the interspecific differences regarding the presence/absence of the capacity for thermal acclimation may prevent the generalization of physiological responses to thermal changes ( Van der Have and De Jong, 1996;Seebarcher et al., 2015). ...
... The flow rates in each chamber were adjusted to approximately 20 mL min −1 to maintain the percentage of particles cleared from the inflow of the chamber at around 20% (Filgueira et al., 2006). The oxygen concentration in the individual chamber was kept at a saturation level above 80% (Bougrier et al., 1995). Furthermore, monthly clam collections were carried out from January 2016 to November 2018, for the interannual comparison of the seasonal cycles of flesh weight under rising winter minimum and summer maximum temperatures. ...
... The Q 10 of the respiration rate was high (2.02) compared with that (1.29) of the ingestion rate at the temperature elevation of 23-28°C, suggesting that the metabolic rate is more sensitive to temperatures above the optimal value. This indicates that the feeding rate did not increase as much as it compensated for the increased metabolic cost at 28°C (Bougrier et al., 1995;Kang et al., 2015). Conversely, the Q 10 of the ingestion rate was maximized by 3.44 at low temperatures of 3-8°C, indicating a more sensitive response than that (1.74) of the respiration rate to temperature variation. ...
Article
Full-text available
Knowledge of physiological responses of important shellfish species to rising temperatures is crucial in assessing the impacts of climate change on marine aquaculture production. The physiological components of energy balance that support growth performance were measured seasonally at different exposure temperatures in the ark clams ( Anadara kagoshimensis ) cultured in the shallow muddy bottom sediment in Yeoja Bay, Korea. We tested the effects of winter minimum (3–8°C) and summer maximum (23–28°C) temperature elevations on individual physiological processes (ingestion, respiration, egestion, and excretion) and the combined energetic physiology (scope for growth [SFG] and net growth efficiency [ K 2 ] measures). The seasonal cycle of dry flesh tissue weight (DW) was also investigated from January 2016 to November 2018, to compare its variation at contrasting cold vs. warm regimes. The rates of physiological components were related to DW, generating significant allometric equations. The weight exponents of the equations for ingestion rate and respiration rate were low at the winter minimum compared with the remaining season temperatures, indicating a higher thermal sensitivity in larger individuals. The physiological rates that were re-calculated for individual components based on estimates of the slope and intercept of the equations increased with increasing temperature, revealing an incapability of thermal acclimation and a temperature effect at seasonally different endogenous conditions. The thermal sensitivity ( Q 10 ) of the ingestion rate and respiration rate was reversed between the winter minimum and the summer maximum temperature elevations, yielding negative SFG and K 2 values at 3 and 28°C. Furthermore, the interannual difference in the seasonal cycle of clam DW displayed variations in the period of increment prior to spawning and the post-spawning loss/recovery in association with its energy balance status in the winter and summer temperature conditions. Overall, these results indicate that warming is projected to affect physiological performance and the seasonal DW cycle of clams in different manners between winter and summer: physiological benefits and advanced weight gain vs. heat stress and progressive weight loss, respectively. The mechanistic adjustment of the clam energy balance across thermal conditions seems to explain the recent advancement in its seasonal biological cycle, as well as the failure in spat collection and the mass summer mortality observed at this culturing site.
... Previous experimental studies suggest M. gigas can tolerate a wide range of environmental conditions, with growth occurring in temperatures between 10 -40°C and salinities of 10 -30 (Mann et al., 1991). Optimum temperatures for M. gigas growth, reproduction and other physiological processes occur between 18 -23°C (Malouf & Breese, 1977;Mann, 1979;Spencer et al., 1994;Bougrier et al., 1995). With climatic warming expected to continue towards the end of the century, warming waters will likely shift the geographical range of M. ...
... Similar trends in oxygen consumption rates have been reported in situ for M. gigas where the highest and lowest oxygen consumption rates occurred in the summer and winter, respectively (Mao et al., 2006;Casas et al., 2018b). Increasing oxygen consumption with actual temperature agrees with several studies on marine bivalves (Bougrier et al., 1995;Ren et al., 2000;Sarà et al., 2008;Casas et al., 2018b), reflecting an increase in physiological and biochemical reactions with warming. Seasonality in metabolic demand may also reflect life history cycles, which are often linked to seawater temperature (Clarke, 1993;Casas et al., 2018a). ...
Thesis
Full-text available
Contemporary climate change (CCC) and non-indigenous species (NIS) are two of the biggest threats to global biodiversity and together are expected to drive a rapid global redistribution of species by the end of the century. Although understanding the interaction between NIS and CCC is crucial for the management of native ecosystems, forecasting future changes remains a significant challenge. It is thus recognised that understanding the physiological mechanisms that shape distributions and promote NIS spread is necessary to make robust forecasts under CCC. In this thesis, novel experimental and ecological niche modelling (ENM) techniques were combined to explore how the highly successful NIS, the Pacific oyster Magallana gigas, may be affected by end-of-the-century environmental conditions. The present research has shown during long-term exposure that M. gigas individuals were physiologically tolerant to CCC conditions predicted for the end of the century. It was evident that M. gigas has a broad environmental tolerance and have undergone rapid niche shifts during introduction that have likely facilitated its current rapid global spread. In addition, both correlative and mechanistic ENMs predicted that M. gigas will undergo a poleward range expansion by the end of the century. Modelling with inter-individual variability showed complex geographical changes in life-history traits in response to CCC. It was apparent that both correlative and mechanistic ENMs can complement each other and provide a unique insight into the predicted changes in species' niches under environmental change. This thesis presented the first long-term, multi-factor mesocosm study of M. gigas, tested the differences between popular niche shift frameworks and presented the first bioenergetic model combining inter-individual variability and environmental variability to predict species responses to CCC across large geographical areas. Taken together, a combination of techniques has produced robust predictions forecasting the continued survival and spread of M. gigas under end-of-the-century CCC.
... Thus, on the 7 th sampling date, when mussels were size-differentiated after 5 months in the laboratory, CRs, RMRs, and SMRs were recorded in all the 95 individuals and plotted against the LWs for comparison of allometric exponents. Previous studies based on the simultaneous measurements of clearance and metabolic rates along the size range of bivalve populations have reported lower mass-exponents for CR than for metabolic rate [38][39][40][41][42][43][44][45], indicating that with increasing body weight, the mass-specific filtering activity decreases at a higher rate than the mass-specific metabolic rate; therefore, the energy balance tends to decrease with an increase in size, which provides a physiological interpretation for the age-related decline in growth efficiency. On the other hand, this kind of differential behaviour of CR vs. metabolic rate is interpreted on the assumption that SMR scales faster with body size than does RMR, which results in a smaller fraction of metabolic energy, the metabolic scope for feeding and growth (MSFG = RMR-SMR), which is available for these functions as the size increases. ...
Article
Full-text available
Body-size scaling of metabolic rate in animals is typically allometric, with mass exponents that vary to reflect differences in the physiological status of organisms of both endogenous and environmental origin. Regarding the intraspecific analysis of this relationship in bivalve molluscs, one important source of metabolic variation comes from the large inter-individual differences in growth performance characteristic of this group. In the present study, we aimed to address the association of growth rate differences recorded among individual mussels ( Mytilus galloprovincialis ) with variable levels of the standard metabolic rate (SMR) resulting in growth-dependent shift in size scaling relationships. SMR was measured in mussels of different sizes and allometric functions fitting SMR vs. body-mass relationships were compared both inter- and intra-individually. The results revealed a metabolic component (the overhead of growth) attributable to the differential costs of maintenance of feeding and digestion structures between fast and slow growers; these costs were estimated to amount to a 3% increase in SMR per unit of increment in the weight specific growth rate. Scaling exponents computed for intraindividual SMR vs body-mass relationships had a common value b = 0.79 (~ ¾); however, when metabolic effects caused by differential growth were discounted, this value declined to 0.67 (= ⅔), characteristic of surface dependent processes. This last value of the scaling exponent was also recorded for the interindividual relationships of both standard and routine metabolic rates (SMR and RMR) after long-lasting maintenance of mussels under optimal uniform conditions in the laboratory. The above results were interpreted based on the metabolic level boundaries (MLB) hypothesis.
... Maulvault et al. (2018) reported that the bio-accumulation and depuration of chemical contaminants in the carpet shell clam, Ruditapes philippinarum, and the Mediterranean mussel, Mytilus galloprovincialis were greatly influenced by temperature due to the organisms' metabolism as well as physiological responses of the animal. In the Pacific oyster, Crassostrea gigas, the clearance rate increased with temperature until a critical point of 19 • C (Bougrier et al., 1995). Whereas, the physiological optimum temperatures for C. virginica were around 20-24 • C (Lannig et al., 2006;Cherkasov et al., 2007). ...
Article
The effect of temperature, salinity and body-size on depuration of naturally accumulated heavy metals in clams, mussels and oysters harvested from Ashtamudi and Vembanad estuaries of Kerala, India were investigated using a static depuration system. Before depuration, the concentrations of heavy metals such as Ni, Co, Fe, Mn, Cu, Pb and Zn were analysed and it was found that the Fe, Zn, Cu and Pb contents in all the bivalves were above the prescribed limit which poses a significant health risk to bivalve consumers. To protect consumer food safety, depuration experiments were conducted at varying temperatures, salinities and body-sizes. The clams, mussels and oysters depurated under the room temperature depuration system (RTDS) showed a better reduction of heavy metals compared with low-temperature depuration system (LTDS). ANOVA showed clams and mussels depurated at RTDS significantly (p < 0.05) reduced the heavy metals than LTDS. However, there was no significant (p > 0.05) difference in oysters between RTDS and LTDS. Further, clams and mussels depurated at low salinity (15-psμ) showed high resistance against Pb reduction. But, all the heavy metals, particularly, Pb, Fe, Zn and Cu were effectively removed at higher salinity depuration (25-psμ and 35-psμ). Moreover, irrespective of the body-size of clams, mussels and oysters used for depuration, a significant (p < 0.05) reduction in all metals (Ni, Co, Fe, Mn, Zn, Pb and Cu) was observed. Relatively, the medium-size bivalves showed higher reductions compared to small-size bivalves. Based on the experiments conducted, we recommend 48 h depuration using the static system under room temperature (30 ± 1 °C) with a salinity range of (25–35 psμ) using medium-size bivalves (clam>30 mm; mussel >45 mm, and oyster >65mm length) as optimum conditions for producing safe bivalves for consumption in the tropics.
... Increasing pieces of evidence are showing that temperature is a strong environmental driver of diseases in the oyster. Notably, oyster disease occurrences are more severe at the proximity of tropical regions likely due to the propensity of many pathogens to grow in warmer waters (Bougrier et al. 1995;Porter et al. 2001;Leung and Bates 2013). For example, in the Gulf of Mexico, oyster disease infection severity and prevalence has been intense during the warm-dry La Niña events (Powell et al. 1996). ...
... L'huître va pomper l'eau de mer afin de filtrer les particules utiles à son développement comme le phytoplancton, le calcium ainsi que l'oxygène. En plus d'extraire de l'oxygène pour la respiration, les branchies agissent comme un filtre qui retient les particules (Gerdes, 1983 ;Bougrier et al., 1995Bougrier et al., , 1998Goulletquer et al., 1999Goulletquer et al., , 2004. On retrouve aussi le manteau, tégument, permettant de protéger et recouvrir la chair de l'huître. ...
Thesis
Les microplastiques (MP) sont largement répandus dans les zones côtières et les océans du monde entier. Les MP sont préoccupants sur le plan environnemental en raison de leurs impacts potentiels sur un large éventail d’organismes marins, de sorte que l'évaluation de leur impact sur les écosystèmes est devenue une priorité de recherche. En complément, les substances phytosanitaires utilisées régulièrement en agriculture se déversent dans les milieux côtiers, par ruissellements. Ces travaux de thèse se sont focalisés sur (i) une étude exploratoire d’un site pilote des Pertuis Charentais (PC) afin d’évaluer l’importance de la contamination plastique et pouvoir évaluer leur toxicité sur (ii) les stades précoces et (iii) tardifs de développement de l’huître creuse, Crassostrea gigas. Ces travaux fournissent une première investigation de l’état de contamination plastique (macro et micro) d’un site d’étude littoral des PC, où la présence de plastiques ostréicoles ainsi que des concentrations élevées en MP dans les sédiments de plage ont été identifiés. De plus, les expérimentations menées en conditions de laboratoire contrôlées, nous informent sur le caractère toxique des MP de PE et des pesticides sur les stades précoces de développement (embryo-larvaire) de l’huitre creuse. Les pesticides dosés dans les eaux des PC ont montré des effets significatifs à des concentrations proches de l’environnement naturel alors que les MP s’avèrent toxiques pour des concentrations plus fortes. Ces effets apparaissent sur le développement, la croissance et le comportement natatoire des larves d’huitre creuse. Des expérimentations complémentaires, effectuées sur des stades plus tardifs, notamment les naissains d’huitre creuse, ont permis de montrer un comportement valvaire modifié suite à une exposition de 25 jours aux MP de type PE et au Chlortoluron, en conditions de laboratoire. Les effets intergénérationnels ont pu être observés avec l’utilisation de MP environnementaux (cocktail de PE, PP et PVC), vieillis aux abords des concessions ostréicoles. La qualité et le succès de fécondation ont été modifiés ainsi que le développement et le comportement de nage des larves-D issues de parents préalablement exposés durant deux mois. Ces premiers résultats permettront de renforcer les connaissances de la communauté scientifique et d’informer les professionnels et acteurs conchylicoles sur les risques des contaminants émergents, tels que les MP et les pesticides. Des adaptations des pratiques conchylicoles seront nécessaires afin d’éviter une probable dégradation de la qualité des eaux littorales dans les PC.
... Although some studies reported no correlation (e.g. in the golden mussel Limnoperna Fortunei by Pestana et al., 2009), in most cases, body size or biomass were reported to be positively correlated with the filtration rates in the zebra mussel (Dreissena polymorpha) (e.g. Reeders and bij de Vaate, 1990; Berg et al., 1996) as well as in many bivalves (eg. in the Pacific oyster Crassostrea gigas by Bougrier et al., 1995). Along the south-east coast of the BoB, the histological analysis revealed that P. viridis have a clear annual reproductive cy cle with five successive gametogenesis stages such as resting, development, mature, spawning and spent (Asaduzzaman et al., 2019). ...
Article
Multifaceted linkages among eco-physiological factors, seasonal plankton dynamics and selective feeding behavior of the green mussel (Perna viridis) in the southeast coast of the Bay of Bengal ABSTRACT Feeding behavior of marine bivalves is largely regulated by the interactive effects of various intrinsic biological factors and extrinsic ecological factors. Therefore, an integrated multivariate approach was applied to explore a deeper knowledge about the feeding biology of the green mussel (Perna viridis), collected from the southeast coastal regions of the Bay of Bengal in Bangladesh, by interlinking among ecological factors, seasonal plankton dynamics, reproductive traits and plankton ingestion data. The correlation test, multivariate approaches and cluster analysis displayed that both the water parameters and ingested gut plankton abundance and their compositions were predominantly influenced by the seasonality and ecological factors of the environment. The se-lectivity indices analysis confirmed that green mussels preferentially ingested on the selective taxa of plankton. The multivariate analyses revealed that plankton ingestion by green mussels was not discriminated by their sexual dimorphism, however, it displayed an enhancement during their gonad development and maturation stages confirming that P. viridis espouses opportunistic patterns to build up their gonads by utilizing energy from the ingested planktons available in the water column. The correlation outcomes consistently demonstrated that the quantitative ingestion of plankton was positively correlated with the gonadosomatic index value of the green mussels. Although, green mussels predominantly ingested the Coscinodiscophyceae (20-60% of total ingestion), they also selectively ingested an increased amount of Bacillariophyceae, Fragillariophyceae, Dinophyceae and zooplankton during their gonad development and maturation stages to meet the special and unique metabolic requirements of crucial gametogenesis stages. Taken together all datasets, principal component analysis (PCA) was applied: the first two principal components showed that seasonality and reproductive cycle explained >47% of the variability. In both cases, PCA analysis revealed that the multiplex scenario of selective ingestion of P. viridis on different plankton taxa were predominantly interlinked with the seasonality, ecological drivers, and plankton biomass and their community structure in the water column depending on the metabolic energy requirement during their crucial gametogenesis stages. Finally, the outcomes from these broad datasets provide a better understanding about the selective feeding behavior of P. viridis, which is essential to maintain the sustainability of the ecosystems as well as to improve the growth and productivity of the existing production systems of this important species.
Preprint
Body-size scaling of metabolic rate in animals is typically allometric, with mass exponents that vary to reflect differences in the physiological status of organisms of both endogenous and environmental origin. Regarding the intraspecific analysis of this relationship in bivalve molluscs, one important source of metabolic variation comes from the large inter-individual differences in growth performance characteristic of this group. In the present study, we aimed to address the association of growth rate differences recorded among individual mussels ( Mytilus galloprovincialis ) with variable levels of the standard metabolic rate (SMR) resulting in growth-dependent shift in size scaling relationships. SMR was measured in mussels of different sizes and allometric functions fitting SMR vs. body-mass relationships were compared both inter- and intra-individually. The results revealed a metabolic component (the overhead of growth) attributable to the differential costs of maintenance of feeding and digestion structures between fast and slow growers; these costs were estimated to amount to a 3% increase in SMR per unit of increment in the weight specific growth rate. Scaling exponents computed for intraindividual SMR vs body-mass relationships had a common value b = 0.79 (~ ¾); however, when metabolic effects caused by differential growth were discounted, this value declined to 0.67 (= ⅔), characteristic of surface dependent processes. This last value of the scaling exponent was also recorded for the interindividual relationships of both SMR and RMR after long-lasting maintenance of mussels under optimal uniform conditions in the laboratory. The above results were interpreted based on the metabolic level boundary (MLB) hypothesis.
Article
Bivalve aquaculture is a major industry supporting food production in coastal areas. Although sea water temperature increase due to climate change is expected to affect marine ecosystems in a variety of ways, it is important to determine whether changes in water temperature and associated changes in the trophic conditions will enhance or inhibit the production of bivalves. In this study, I conducted a field survey of environmental factors and growth rates of the Pacific oyster (Magallana gigas) in the subarctic estuarine areas (Akkeshi-ko Lagoon and Akkeshi Bay) and evaluated the effects of climate warming using numerical simulations. In situ cage experiments with two different year-classes were conducted and oyster growth varied between the two stations in the 2nd year-class mainly in response to spatial variation in water temperature. A three dimensional physical-ecosystem coupled model including a growth model of oyster was applied and the model could reproduce the differences in present (the year 2014) growth patterns between stations. The climate warming scenarios showed that oyster production would increase in both lagoon and bay. However, the timing and location of weight loss due to spawning will differ, so caution will need to be exercised regarding the timing of the oyster harvest in the future.
Chapter
This chapter discusses the physiological energetics of marine molluscs. The measurement of the components of the energy balance equation for individual organisms—namely, ingestion, absorption, excretion, and respiration—allows the derivation of the energy available to the animal for growth and for reproduction. In this way, it is possible to analyze the relationships between growth and various endogenous and exogenous variables in terms of underlying physiological processes. The chapter discusses various physiological components of growth in marine molluscs (excluding the cephalopods) in relation to the major variables of body size, seasonal effects, temperature, oxygen concentration, and ration level. Studies on energy flow at the population level indicate the average rates and efficiencies that have been reported in the major trophic categories. Three efficiencies of energy transfer are commonly considered: (1) absorption efficiency (A/C); (2) gross growth efficiency (P/C); and (3) net growth efficiency (P/A). The concept of scope for growth, which was regarded as the difference between the energy of the food an animal consumes and all other utilizations and losses, has descriptive validity for a wide range of environmental variables and has been widely used in the study of physiological adaptation in molluscs. Recent advances in knowledge of the population genetics of marine molluscs pose a challenge to the whole-animal physiologist, and future research in either discipline must clearly take account of recent understanding that derives from the other.
Article
Quantities of faecal material produced by the Japanese oyster varied seasonally, reaching maxima in October. This seasonal rate was caused by activities of the gills of oysters. Daily quantities (V) of suspended matter removed by the gills of a single oyster could be calculated by means of the equation V(mg/day)=suspended matter (mg/l) × filtration rate (l/h)×24. As a part of this calculated quantity was digested and absorbed, quantities of faecal material produced were a little smaller than that of suspended matter calculated using the above equation. Oysters retained approximately 40 to 50 per cent of the suspended matter contained in the inhalent current and this rate did not vary throughout the year, therefore, daily quantities of suspended matter removed could also be estimated from the rates of water transport. Rates of filtration and water transport per gram wet weight of meat were a linear function of the water temperature (t°C) and could be expressed by equations Filtration rate (l/h/g of meat) =-0.308+0.066t Rate of water transport (l/h/g of meat)=-0.002+0.109t
Article
The efficiency of energy transfer by a population of the farmed pacific oyster, Crassostrea gigas was studied during culture period of 10 months July 1979-April 1980, in Geoje-Hansan Bay near Chungmu City. Energy use by the farmed oyster population was calculated from estimates of half-a-month unit age specific natural mortality rate and data on growth, gonad output, shell organic matter production and respiration. Total mortality during the culture period was estimated approximate from data on survivor individual number per cluster. Growth may be dual consisted of a curved line during the first half culture period (July-November) and a linear line in the later half period (December-April). The first half growth was approximated by the von Bertalanffy growth model; shell height, , where t is age in half-a-month unit. In the later half growth period shell height was related to t by SH=4.44+0.14t. Dry meat weight (DW) was related to shell height by log $DW=-2.2907+2.589{\cdot}log\;SH,\;(2
Article
Filtration rates for Mytilus edulis L., Cerastoderma edule (L.) and Venerupis pullastra (Montagu), using concentrations of Phaeodactylum that were found to give optimum results, were compared with rates of water transport recorded for other species. When expressed in terms of soft body wet weight there seems to be no clear distinction between epifaunal, non-siphonate bivalves and infaunal, siphonate species. There is a close correlation between the nitration rates of the three species when compared on a basis of the porosity of the gill.Filtration rates and pseudofaecal production for the three species have been determined for increasing concentrations of various types of suspension to arrive at some indication of the efficiency and the methods which these bivalves show in controlling ingestion. Two methods are apparent; 1.1) by increasing the proportions of material rejected as pseudofaeces (e.g., Mytilus edulis), and2.2) by reducing the amount of material filtered by reducing filtration rates (e.g., Cerastoderma edule and Venerupis pullastra). As determined from the ability to maintain rates of ingestion at a constant level after a ‘satiation point’ is reached, Mytilus edulis is more efficient in controlling rates of ingestion with increasing concentration of suspension than the other two species. The rates of ingestion of particles at any one concentration was roughly proportional to the size of the particles, with the exception of Isochrysis and Platymonas which were ingested in smaller amounts than accounted for by their size alone; potential sources of food (algae) were not ingested in larger amounts than were inorganic particles.
Article
Physiological stress was quantified in specimens of the European flat oyster Ostrea edulis, acclimated to a matrix of temperature (5-25-degrees-C) and salinity (16-34 parts per thousand) conditions, using the Scope for Growth (SFG) index. Variations in the index were interpreted from the responses of its components, absorption efficiency, filtration rate, respiration and ammonia excretion rates, to external conditions. Mean SFG values were most influenced by acclimation temperature but significant differences were found between animals at different salinities over the range tested. There was a severe reduction in SFG when high temperature was combined with reduced salinity (less-than-or-equal-to 19 parts per thousand) and a less severe, but still marked, diminution in SFG was also observed when animals were subjected to low temperatures and reduced salinity. The responses at the extremes of the temperature and salinity ranges may be interpreted as differential and synergistic effects of the two environmental variables on the components of the SFG index. The laboratory studies can be related to observations of O. edulis in the field.
Article
When individuals of 5–811 mg dry tissue weight were fed 100 × 106 cells l−1Isochrysis galbana for 24 h in Winter's (1973) apparatus the filtration rate (ml h−1 oyster−1) increased with increasing body size following the allometric equation FR=1.2W0.73 where W is dry tissue weight in mg.Filtration rate at three different algal densities decreased with increasing densities, showing that C. gigas can regulate the filtration rate in that concentration range. The amount of water filtered free of particles was in the ratio 1:2:3 with decreasing concentrations from 100 to 75 and 50 × 106 cells l−1I. galbana. Consequently, the amount of algae removed was more or less constant at all three concentrations.Assimilation efficiency was found to be more or less constant, not being significantly dependent on body size or algal concentration.Filtration rates of oyster larvae were determined by measuring the decrease in algal concentration with time. When fed 50 × 106 cells l−1 of both I. galbana and Chaectoceros calcitrans filtration rates increased from about 0.5 to 100 μl h−1 larva−1 during larval development. Filtration rates increased discontinuously with increasing body size; larvae from about 77–120 μm shell length filtered less actively than larvae > 120 μm shell length; a marked drop in filtration activity was shown for larvae > 300 μm shell length approaching metamorphosis.Like adult oysters, the larvae regulate the amount of food ingested in different concentrations by adapting their filtering activity to different concentrations. When fed mixed algal cultures, food uptake is greater than by feeding monocultures.