© 2003 by ICES/CIEM International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer
The pelagic life of the pectinid Pecten maximus—a review
Universite de Bretagne Occidentale, Institute Universitaire Européen de la Mer UMR CNRS 6539 Technopôle Brest-Iroise, Plouzane 29280, France
*Correspondence to Marcel Le Pennec; tel: +33 2 98 498641; fax: +33 2 98 498790. e-mail: marcel.lepennec{at}univ-brest.fr.
Although marine bivalves go through a planktonic larval phase, knowledge of this phase is often poor because of the difficulty in identifying and monitoring the activity of these tiny organisms within the water mass. Some bivalves have been studied more than others, often because of their economic value. These species can serve as a model for improving our understanding of the circumstances of planktonic larval development, in particular by assessing its impact on recruitment. This review is aimed at summarizing the knowledge on the pelagic life of Pecten maximus acquired by research in France over the last 25 years. The comparison of these results with those obtained elsewhere for pectinid species, indicates certain characteristics that appear to be fairly common to all coastal infralittoral pectinids. Regardless of species, pelagic life of pectinids starts with the release of gametes, followed by fertilization and embryonic and larval stages until metamorphosis and recruitment to the benthic community. After consideration of the main characteristics of the pelagic stages and their sensitivity to certain environmental factors, a graphic synthesis is provided displaying their migratory behaviour and the possible consequences for recruitment.
Keywords: pelagic life, larval characteristics, Pecten maximus, pectinids, hatcheries
Received 2 July 2001; accepted 29 July 2002.
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Introduction |
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During the last 30 years, studies have been undertaken to develop the aquaculture of commercially valuable scallops. Since the 1970s, improvements in experimental rearing techniques for bivalves, developed initially by Loosanoff and Davis (1963), have allowed successful routine reproduction of some 20 bivalve species in commercial hatcheries, including around 10 pectinids (Le Pennec, 1997).
The demand for Pecten maximus (L.) spat to replace stocks depleted by intensive fishing or to establish new fishing sites has led both to the collection of natural offspring and to laboratory culture (Le Pennec, 1974; Buestel et al., 1982). In Spain, France, Great Britain and Ireland, this pectinid is of major economic importance, and consequently research on this species has been more intensive than on other pectinids such as Aequipecten opercularis and Mimachlamys varia. The main results for P. maximus larvae have been obtained from laboratory studies conducted at University of North Wales (Menai Bridge, UK), the University of Western Brittany (Brest, France) and IFREMER (Brest). Hatchery data and in situ studies can also be exploited. As a result of experimental rearing, the morphogenesis of P. maximus larvae as well as the environmental conditions required for their development have been described (Comely, 1972; Gruffydd and Beaumont, 1970, 1972; Le Pennec, 1974; Le Pennec and Rangel-Davalos, 1985; Cragg, 1980; Beaumont and Budd, 1983; Beaumont et al., 1987; Salaün, 1994).
The family of the Pectinidae is represented in most of the world's seas. Because of their excellent food quality and large biomass, some species provide an important economic resource, for instance for Japan (Ito, 1991), Canada (Naidu, 1991) and Chile (Avendaño, 1993). However, for any of these species, the exploitation of natural beds raises problems because of interannual variations in biomass. The literature provides many examples of such variations and the sometimes dramatic consequences for fisheries, e.g. P. maximus (Ansell et al., 1991; Paulet et al., 1997), Placopecten magellanicus (Dickie, 1955; Caddy, 1979; Naidu, 1991), Argopecten gibbus (Moyer and Blake, 1986), Pecten novaezelandiae (Bull, 1991), Pecten vogdesi and Nodipecten subnodosus (Stoz and Mendo, 2001), Argopecten purpuratus (Avendaño, 1993; Stoz and Mendo, 2001), and M. varia (Conan and Shafee, 1978).
From 1985 to 1998, a French scientific program (PNDR: National Program for Determinism and Recruitment) has been carried out to provide a scientific database for better understanding of abundance fluctuations in selected marine species including P. maximus. This review summarizes the research supported by this program and is aimed specifically at answering the following questions:
- – Taking into account the difficulties encountered in following larvae in their natural environment, are data on larval characteristics obtained with stock hatching transferable to the natural surroundings?
- – Does the information on larval development depends on the research methods used?
- – To what extent do environmental factors affect larval development and have measurable effects on recruitment?
- – Is it possible to draw up a global scheme of P. maximus behaviour during its pelagic life?
- – Does the information on larval development depends on the research methods used?
To answer the first two questions, the information on the pelagic development of pectinids has been arranged according to four major events representing consecutive morphological and physiological transformations: gamete emission, fertilization, hatching and metamorphosis. Figure 1 provides a description of the P. maximus life cycle. Next, the environmental factors affecting the pelagic life stages, and consequently recruitment, are discussed.
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Pelagic development |
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Gamete emission
The main statistic used to characterize fecundity is the number of oocytes emitted by an adult individual during one emission. Generally, one emission continues for 1 h for spermatozoa and 30 min for oocytes. One individual is able to spawn again after only 1 week of conditioning. Available estimates range from 15x106 oocytes in St. Brieuc Bay to 21x106 in Brest Bay (average for 6 years of observation) for a 3-year-old P. maximus (Table 1). Gamete emission of the giant scallop P. magellanicus has been estimated at 10x106 and 20x106 oocytes for a 3- and 4-year-old individual, respectively (Langthon et al., 1987). According to Barber et al. (1988), emission changes with depth, ranging from 3.1–6.6x107 oocytes at a shallow site to 1.4–2.4x107 at a deep site. Variations in gamete emission have been related to seasonal variation in food availability in the following species: Mizuhopecten yessoensis (Maru, 1976), P. magellanicus (Thompson, 1977), M. varia (Burnell, 1983) and P. maximus (Lubet et al., 1987; Paulet et al., 1995). Relationships among food, temperature and gametogenesis have also been considered: Argopecten irradians (Sastry, 1966), P. maximus (Stanley, 1967), Aequipecten tehuelchus (Orensanz, 1986), A. purpuratus (Illanes-Bucher, 1987; Wolff, 1988) and Pecten jacobeus (Mestre, 1992).
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Although the effect of other factors cannot be discounted, the main factor triggering gamete emission is sea temperature (Thorson, 1950). Paulet et al. (1997), recognizing the essential role of temperature in this context, recommend the use of different temperatures during the conditioning of broodstock in hatcheries, which would give the best results in nature, i.e. 10–13°C for animals in Brest Bay during spring conditioning.
Embryonic stage
The embryonic stage follows fertilization and lasts until prodissoconch I is formed (Figure 1). Observation of this stage has been limited to the controlled environment of the laboratory. For P. maximus, around 24 h is required after spawning to obtain trochophores at temperatures between 16 and 17°C (Comely, 1972), and 48 h for D larvae (Le Pennec, 1974; Cragg and Crisp, 1991). Casse (1995) obtained the first veligers in only 30 h at 19°C (Table 2). There are differences among pectinid species. P. magellanicus develops its first veligers after 4–5 days at temperatures between 10 and 13°C (Desrosiers et al., 1995), and M. yessoensis after 5–7 days (Yamamoto, 1960). Regardless of species, development of this stage depends mainly on temperature conditions (Wright et al., 1983, 1984).
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The reserves initially contained in the oocyte represent the only energy source for the embryo. Paulet et al. (1988) showed that the time required to reach metamorphosis is shorter for P. maximus larvae from the largest eggs, while Krauter et al. (1982) noted that A. irradians larvae from the largest eggs have a better chance of survival than those from smaller eggs. These observations are valid for many pectinids (Le Pennec et al., 1998).
Its short life and fixed energy source make the lecithotrophic embryo relatively independent of environmental conditions. Embryonic life appears to be much more conditioned by endogenous factors than by exogenous factors, with the exception of temperature (Cochard and Gérard, 1987).
Larval stage
The larval stage groups together prodissoconch I and II veligers up to the pediveliger period (Figure 1). The existence of a shell facilitates measurement of the growth of individuals.
Commercial hatcheries have recorded mean hatching rates (for 14 years of data collection) in P. maximus of about 29% (Robert and Gérard, 1999), although variations are large from one year to another, even for oocytes incubated under identical conditions (Robert et al., 1994). In situ, better rates of hatching (Table 1) were obtained in June for individuals from Brest Bay (Paulet et al., 1997), and in July for those from St. Brieuc Bay (Paulet et al., 1992). In hatcheries, the eggs which give the best rates of hatching (as defined in Table 1) are those produced simultaneously with the best spawning periods in nature, i.e. April to July.
Growth rates in the laboratory depend on the quality of the algal mixture provided. Observations range from 2.5 to 5.3 µm d–1 (Table 2). Cochard and Gérard (1987) considered that a growth rate of 3–3.5 µm d–1 was low, 3.5–5.5 µm d–1 moderate, and 5.5–7.5 µm d–1 high. As a consequence of variations in growth rate, the duration of the larval stage also varies. The average for hatchery-reared P. maximus larvae based on 14 years of data was 25 days (Robert and Gérard, 1999), compared to 20–24 days for A. purpuratus, 20–26 days for Argopecten ventricosus, 25–27 days for Nodipecten nodosus (Uriarte et al., 2001) and 30–40 days for M. yessoensis (Yamamoto, 1960).
In situ, only the duration of the entire pelagic phase can be estimated as the time between gamete release and settlement on spat collectors. Observed values range between 18 and 42 days for P. maximus (Table 2). Salaün (1994) estimated a growth rate of 1.4 µm d–1 in St. Brieuc Bay. Dadswell et al. (1987) found growth rates of 2.5–4 µm d–1 for P. magellanicus in the Bay of Fundy (Canada), i.e. values similar to those determined experimentally by Culliney (1974).
Under hatchery conditions, the analysis of a large number of batches of larvae has provided a model for the development of the larval shell of P. maximus. From this model, a definition of the morphological criteria of normality may be derived, such as the maximum intervalve distance for a shell height of 90 µm: the Dim 90 index (Salaün et al., 1991). When this index was applied to larvae sampled from St. Brieuc Bay during the reproductive season of 1987, an estimated 13% of individuals exhibited malformations (Salaün, 1994).
In hatcheries, the proportion of larval abnormalities (Table 1) revealed by shell malformations (irregular curvature of valves, cracks in the striation, shell surface wavy in outline) observed on the second day of rearing is generally around 7.5% (Robert and Gérard, 1999). The survival of abnormal larvae is extremely low and they mostly die before metamorphosis. Most pectinids show such abnormalities, e.g. P. magellanicus (Culliney, 1974) and A. purpuratus (Avendaño, 1993).
The malformations are generally associated with slow-growing larvae characterized by a poorly developed velum, leading to a deficiency in the mucociliary activity of this organ and a decrease in locomotion speed and the rate of seston particle capture (Strathmann, 1979). They are usually attributed to endogenous factors such as self-fertilization or polyspermy (Beaumont and Budd, 1983), or even to membrane and cytostructural lesions (Dorange et al., 1989). Under natural conditions, depletion of larval storage products is not necessarily or entirely compensated by exotrophy. As a result, these larvae have little chance of undergoing metamorphosis (Salaün, 1994). However, biochemical and cytostructural qualities are probably even more important than the number of oocytes emitted (Dorange et al., 1989; Le Pennec et al., 1990, 1998), as they have a direct effect on hatching rate (number of D larvae divided by the number of oocytes).
Veligers do not necessarily represent the most fragile stage during rearing. Depending on season, excellent survival (or larval yield: the ratio of pediveligers to D larvae at day 2) may be obtained (Table 2). The only estimates available for survival under natural conditions range from 31 to 73% for P. maximus (Salaün, 1994).
Larvae develop a ciliated velum that allows locomotion and then progressively the capture of food particles. In the laboratory, the embryos of P. maximus become mobile at the gastrula stage (8–12 h after fertilization), although their whirling movements do not allow them to move far from the base of the tank (Casse, 1995). Although spiral movements are possible at the trochophore stage (20–25 h after fertilization; Casse, 1995), only veligers (2 days after fertilization) are capable of travelling over much greater vertical distances and of performing helicoid swimming because of their velum (Cragg, 1980). The periods of active swimming alternate with periods of passive sinking towards the tank bottom on which the larvae may rest. Data on larval behaviour in natural surroundings are limited. However, plankton samples taken from different depths in Brest Bay showed a shortage of D larvae (<100 µm) compared to older veligers (110–150 µm).
These swimming periods are not yet of primary trophic importance, because the individuals still contain sufficient yolk reserves. However, as shown for Mytilus edulis (Lucas et al., 1986), exhaustion of the supply of storage products may make planktotrophy obligatory around day 6.
Settlement, metamorphosis and recruitment
The final stage of pelagic life is characterized by the development of an eyespot, a foot and the appearance of a double ring (Gérard et al., 1989) on the shell edges. The double ring corresponds to a peripheral groove on which the future post-larval shell (dissoconch) will be attached (Robert and Gérard, 1999). This feature can be clearly seen and is used in hatcheries to assess the capability of larvae to undergo metamorphosis (Gérard et al., 1989). The larvae, which are then referred to as pediveligers, remain close to the bottom and search for a substrate suitable for settlement (Culliney, 1974; Cragg and Crisp, 1991; Dwiono, 1992). At this stage, they may be collected on artificial substrate collectors (Thorson, 1950; Chauvaud, 1998). To date, little is known about the physical, chemical and biotic features that attract pectinid pediveligers to specific substrates (Carriker, 1988; Nicolas, 1999). Various factors potentially affecting settlement and/or metamorphosis (Table 3) have been tested in the laboratory. However, only turbulence appears to have a beneficial and reproducible effect on settlement and metamorphosis of P. maximus larvae in hatcheries (Nicolas, 1999).
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In the natural environment, different pectinids do not show the same ability for settlement on artificial collectors. Observations for P. magellanicus (Culliney, 1974) and M. yessoensis (Golikov and Scarlato, 1970) suggest that the pediveliger larva, once settled, is positively geotropic or geotactic, or negatively phototropic. A. purpuratus appears to have an exceptional preference for settlement on a red alga, Rhodymenia sp. (Avendaño, 1993; Cantillanez, 2000), whereas various mineral and organic substrates are used by many other pectinids (Brand et al., 1980). Spat has been collected from clean silt-free surfaces of many sorts, and evidence for species-specific settlement stimuli or chemically attractive surfaces is largely absent (Brand et al., 1980; Navarte et al., 2001). Sediment type and hydrodynamic conditions prevailing at the sediment–water interface are the main factors determining settlement of P. maximus pediveligers (Thorson, 1950). A high silt content may have negative effects on some physiological processes such as respiration and feeding (Gruffydd and Beaumont, 1972), whereas excessive turbulence may cause juvenile mortality (Thorson, 1950). Biotic interactions such as competition and predation are also important factors. Chauvaud (1998) proved that simultaneous attendance of post-larvae of P. maximus and their main competitors (e.g. A. opercularis) on fixation support involves a direct competition for space and food. According to several authors (Thorson, 1966; Mileikovsky, 1974; Woodin, 1976), the presence of adults is of prime importance to enhance the chances of settling and/or settled larvae to survive. More generally among bivalves, several examples of intraspecific interactions of this type exist, where adults have a negative effect on recruitment, e.g. in Cerastoderma edule (Hancock, 1973; Bachelet et al., 1992a) and Spisula ovalis (Berthou and Glémarec, 1988). The competition involves essentially ingestion of larvae or disturbance of sediments and burying of pediveligers or young recruits. Among pectinids, intraspecific competition is likely in several species, including Chlamys islandica (Vahl, 1982) and M. yessoensis (Ventilla, 1982).
The secretion of mucous filaments by the foot (Dwiono, 1992) allows pediveligers to clump together or combine with suspended particulate matter (Salaün, 1994). In hatcheries, pediveligers exhibit such gregarious behaviour when the water is changed to form a mucous netting, where strings of larvae may reach lengths of up to 1 m (Gérard et al., 1989). Similar phenomena have not been observed in situ for P. maximus, but a similar behaviour has been noted in juveniles of C. edule (Bachelet et al., 1992b), possibly to facilitate dispersion.
Different formulations have been developed to determine the success of transition from larval life to metamorphosis (Table 1), including the rate of dissoconch production (Tritar and Lucas, 1989) and the rate of metamorphosis (Salaün, 1994). Rate of dissoconch production represents the ratio of living individuals, developing a dissoconch within a certain lapse of time, to the number of live pediveligers at the beginning of observations, and reported values range from 0 to 52%. The rate of metamorphosis is a more formal measurement, representing the number of post-larvae at day 15 compared to the number of D larvae at day 2, and values range from 0 to 3% in hatcheries. Salaün (1994) estimated the rate of metamorphosis at 2.5% in St. Brieuc Bay in 1987, by relating results obtained from simultaneous in vitro fertilizations and spat collections in situ. The stock increase observed by the fisheries in the early 1990s in St. Brieuc Bay suggests that the metamorphosis rate 3 years earlier must have been relatively high, suggesting that the 2.5% estimated for 1987 is higher than usual.
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Environmental factors |
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Despite considerable progress in hatchery technology, aquaculture of P. maximus is not yet competitive with the exploitation of natural beds. Nonetheless, recruitment variations have a marked influence on the fisheries of wild populations (Boucher and Fifas, 1995). On the basis of experimental results, the pelagic phase does not appear to be the life stage most sensitive to variations in environmental conditions, although some factors negatively affecting larval populations have been identified.
Hydrological conditions
Temperature has a strong influence on recruitment, particularly by affecting adult sexual maturation (Boucher and Dao, 1990; Paulet et al., 1992, 1997). Hatchery results indicate that most larvae obtained from broodstock conditioned at temperatures below 16°C are abnormal (Cochard and Gérard, 1987). Veligers are also affected by temperature, which may cause a slowdown or even a cessation of growth (Beaumont and Budd, 1983). Veligers hatched in the natural environment are similarly affected (Salaün, 1994). Cragg and Crisp (1991) reported variable larval life spans, ranging from 9 to 70 days depending on species and temperature conditions. Irrespective of the species studied, these authors found a negative correlation between larval life span and temperature. However, growth resumed after temperatures were increased to normal. Thus, this abiotic factor should be looked at in perspective, even though low temperatures increase the pelagic life span by reducing metabolic rate (Salaün, 1994).
Depending on geographical characteristics, some bays harbouring pectinids, such as Brest Bay may be more protected from prevailing winds than others (St. Brieuc Bay). Residual circulation patterns provide the best insight into larval displacement from breeding areas (Thorson, 1950). According to Thouzeau and Lehay (1988), three types of factors account for the movement of water masses: tidal action, wind and density differences owing to variations in temperature and salinity (Figure 2). These authors also determined that P. maximus larvae could travel 10–40 km over an 18-day period solely as a result of tidal action.
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Food
As the larvae use up their vitellin stores, they progressively exhibit planktotrophic behaviour, starting from the second or third day onwards. The food resources exploited vary and include bacteria and cyanobacteria (Prieur, 1981; Salaün, 1994; Nicolas et al., 1998) and dissolved amino acids (Manahan and Crisp, 1983), while phytoplankton (flagellates and diatoms) represents the main component of the larval diet (Culliney, 1974; Le Pennec and Rangel-Davalos, 1985; Salaün, 1994). The distribution of feed-algae over the water column depends on light intensity. Consequently, the larvae follow phytoplankton concentrations, as has been demonstrated for P. magellanicus (Thorson, 1966), P. maximus (Salaün, 1994) and A. purpuratus (Cantillanez, 2000). When the water column is stratified, larval concentrations are closely associated with phytoplankton concentrations. During the day, both may be found at considerable depths, although larvae appear to avoid the colder bottom waters, while they may be observed at the surface after sundown. However, larvae are distributed throughout the water column during periods of non-stratification, because hydrodynamic forces surpass their swimming capabilities.
Food availability is one of the main factors affecting larval development and therefore recruitment. In situ, larvae are able to survive several days without food (Salaün, 1994) and subsequently may resume normal growth once feeding conditions improve. A sufficient quantity of reserves must be built up to allow metamorphosis (Dwiono, 1992). Throughout the pelagic stage, a temporal lack of food could lower chances of larval survival.
Predation
Regardless of the factors involved (Thorson, 1950; Mileikovsky, 1971; Scheltema, 1971; Chia et al., 1984), any prolongation of the larval phase is likely to increase the probability of an individual being eaten by predators and of dissemination of individuals outside a suitable area, as has been demonstrated for Mercenaria mercenaria (Carriker, 1961) or suggested for M. edulis (Fotel et al., 1999). Recently, Ciocco and Orensanz (2001) reviewed and summarized the literature dealing with scallop predators, from various countries of the world.
Organic pollutants and heavy metals
Little information is available concerning the effects of organic pollutants and heavy metals. Laboratory experiments have shown that organic pollutants affect larval development of bivalves, even to the extent that development will come to a complete stop at high doses (Liao and Li, 1980; Beaumont et al., 1987; Beiras and His, 1995). Antifouling organotin compounds prevent the settling of pediveligers (Minchin et al., 1987).
Toxic algal blooms
The increasingly eutrophic conditions of coastal waters are favourable to toxic dinoflagellate blooms during spring and summer when bivalve reproduction is at a maximum. In Ireland, a Gyrodinium aureolum bloom in the Lough Hyne caused a complete disappearance of copepods as well as gastropod and bivalve larvae, including P. maximus (Minchin, 1985). In 1995, the development of a Gyrodinium nagasakiense bloom in Brest Bay caused an interruption of feeding activity and shell growth of P. maximus, leading to impaired gamete production and larval and post-larval mortality (Chauvaud, 1998). A review of harmful algal blooms against pectinids and other bivalves was recently given by Blanco-Pérez (2001).
Bacterial infection
Bacterial infections occur frequently during laboratory experiments (Andersen et al., 2000), and larvae are more susceptible than adults (Lambert, 1998). Vibriosis is particularly common in A. irradians larval rearing (Leibovitz, 1989) and Euvola ziczac (Freites et al., 1993). A Vibrio anguillarum-related strain responsible for larval death has been isolated from A. purpuratus in the laboratory (Riquelme et al., 1995). In experimental and commercial pectinid hatcheries, high mortalities often occur unless antibiotics are applied. Lambert et al. (1998) recently identified Vibrio pectenicida in P. maximus, which causes a rapid death of all larvae. Its pathogenic action in situ is unknown, but is considered more harmful when the physiological state of the larvae is sub-optimal (Lambert, 1998).
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Discussion |
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Up to now, the real problem of studying pectinid development during the pelagic phase is the lack of direct investigative means suitable for use within the natural environment. Intermediary techniques must be employed to establish the presence or absence of larvae within a plankton sample. The only available method is to obtain seawater samples in which all planktonic organisms of similar size and/or density are concentrated, followed by a laborious identification and separation process before they can be counted and possibly measured. Interpretation of the results obtained depends on the representativeness of the sample. Moreover, species identification is not completely solved and new tools are needed to improve and speed up the analysis (Garland and Zimmer, 2002).
In the early 1990s, monoclonal antibodies had been proposed for the identification of P. magellanicus larvae (Demers et al., 1993), but to our knowledge, this method has only been used in a single field experiment (Rabby et al., 1994). Another recently developed technique based on the same immunological principle relies on specific protein recognition and is currently being tested on P. maximus larvae sampled from plankton (Paugam et al., 2000). A molecular technique using DNA as a specific marker in adult bivalves has been used to identify individual beds of P. magellanicus in eastern Canada (Patwary et al., 1994; Claxton and Boudling, 1998). If these genetic tools could also be used for the larval cohorts produced, the parental origin of larvae and post-larvae might be established and so also the means by which scallop beds are replenished and dissemination patterns of larvae over larger areas.
The objective of studies undertaken in hatcheries relate to the production of viable larvae that are able to undergo metamorphosis and produce spat. Because of the commercial interests, it is difficult to obtain precise information on rearing conditions and survival. Moreover, criteria used are not always the same. Nevertheless, comparative analyses of results obtained for different pectinids have shown that physiological and ecological requirements are broadly similar, except for slight differences in response characteristics and development time.
Techniques for raising bivalve mollusks would allow recruitment to be controlled and adult production to be stabilized at the level desired by consumers. Yet, despite continual improvements in rearing techniques, aquaculture is not capable of supplanting natural production. Moreover, the best larval yields of P. maximus in terms of growth and survival are still obtained at the beginning of spring and summer, even in the absence of external stimuli (Robert and Gérard, 1999). These periods correspond to those most advantageous for reproduction in the natural environment (Paulet et al., 1997). Thus, control over the complete life cycle under experimental conditions has not yet resulted in a dissociation of the animals from some constraints caused by their natural behaviour. However, even if laboratory experiments may never reveal the total complexity of the behaviour in the natural environment, they have allowed the pelagic life of pectinids to be determined with greater precision under many controlled environmental factors.
One of the main interests in larval behaviour relates to migratory capacity. Based on the available literature, the ability of larvae to migrate towards the surface varies considerably as a function of time. Under experimental conditions, the amplitude of vertical movements increases with the progressive acquisition of exotrophy and then decreases as the period of settlement and metamorphosis approaches. To meet their metabolic requirements, larvae develop a velum to reach their phytoplankton food sources near the surface and to feed efficiently. Kaartvedt et al. (1987) have shown that movements towards the surface take place mainly at night and this has been confirmed to be the case in situ for P. maximus by Salaün (1994) and for A. purpuratus by Cantillanez (2000). Subsequently, pediveligers develop a behaviour related to searching for a settlement substrate, which in hatcheries is sometimes associated with mucus secretion and clumping together of numerous individuals.
To ensure local recruitment to an existing scallop bed, it is essential that the larvae remain in the neighbourhood or find some means to return to the bed. Because the pelagic stages are likely to experience displacement far beyond the beds where post-larvae, juveniles and adults are generally found, some passive or active homing mechanism should be involved. However, as a representative number of larvae cannot be monitored in situ on a regular basis, the consequences of their displacement cannot be determined at present.
The vertical movements of larvae observed under both natural and experimental conditions interact with horizontal movements of the water masses. Thus, the extent of the displacement depends on the combination of autonomic behaviour and hydrologic factors.
As the implications of veliger swimming are numerous, research could be usefully directed towards its study, for instance in mesocosms under varying hydrodynamic conditions (Davis et al., 1996). Special attention should be paid to the pediveliger stage and to the conditions required for clumping together and the role of these ‘stalactite structures’ (Gérard et al., 1989) in larval dissemination. The nature of the contact between pediveligers and substrate during settlement is another crucial consideration.
The development of even the most advanced mesocosms may allow an understanding of the phenomena occurring on the scale of meters, which is not truly comparable with the scales operating in the natural environment. At present, only hydrodynamic models may provide information on the expected range of larval movements (Verdier-Bonnet et al., 1997). However, these simulations cannot yet integrate processes such as larval behaviour having a spatio-temporal field that is incomparable to that of hydrologic movements.
Labelling of larvae is a possible alternative research strategy. However, the development of capture/recapture methods (Rumrill, 1990) may only be considered in sites with a particular geography and where larval densities are high.
The results presented are summarized in Figure 2. Figure 2A indicates the development of swimming characteristics of pectinids throughout their pelagic life and in the absence of hydrologic movement. Figure 2B shows the possible implications of hydrology and climatology during their pelagic life on recruitment.
Although high post-larval density is generally considered predictive of an increase in adults 3 years later, most results show a correlation between interannual variability of larval densities and physical factors (Salaün, 1994). Cantillanez (2000) recently demonstrated a negative impact of climatic factors such as ‘El Niño’ and ‘La Niña’ on the recruitment of A. purpuratus. Physical parameters (weather, temperature and hydrology) are supposed to play a dominant role in recruitment dynamics because during the approximately 3 weeks of the pelagic phase they may affect survival and especially the transfer of larvae to zones that may or may not be favourable for settlement.
In situ, the period between the umbonate and eyespot phase (Figure 2A) appears to be the most sensitive one to prevailing hydrodynamic conditions (e.g. tidal currents, waves), because this is when they are disseminated over the entire water column. This period usually lasts for 8–10 days and covers a corresponding number of tidal cycles. Although larvae cannot be considered as inert particles, in situ studies have confirmed the basic role of hydrodynamic conditions in larval displacement. Thus, in 1985, a strong wind blowing in the opposite direction of the tidal current caused large swarms of larvae to become trapped in a whirlpool located in the eastern part of St. Brieuc Bay, an area with a sandy bottom unsuitable for recruitment (Thouzeau and Lehay, 1988). The decline in catch of adults 3 years later confirmed a poor recruitment of individuals bred in 1985 (Salaün, 1994). Similar results have been obtained for P. magellanicus (Caddy, 1979; Tremblay and Sinclair, 1988, 1990; Tremblay et al., 1994; Rabby et al., 1994) and A. gibbus (Allen and Costello, 1972). Still, larvae dispersed far from the parental stocks may contribute to recruitment elsewhere. While most pectinids appear to follow this model, other parameters may still play a specific role, such as the intraspecific competition for living space observed between larvae and adults of M. yessoensis (Ito, 1991).
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Acknowledgements |
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The authors are grateful for the financial support of the Programme National sur le Déterminisme du Recrutement (PNDR) and the Programme National d'Ecologie Côtière (PNEC).
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References |
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Allen D.M and Costello T.J. (1972) The Calico scallop Argopecten gibbus. NOAA Technical Report. NMFS SSRF 656:1–19.
Andersen S, Burnell G, Bergh O. (2000) Flow-through systems for culturing great scallop larvae. Aquaculture International 8:2–3249–257.[CrossRef][Web of Science]
Ansell A.D, Dao J.C, Mason J. (1991) Development in aquaculture and fisheries science. In Shumway S.E (Ed.). Scallops: Biology, Ecology and Aquaculture(Elsevier, New York) pp. 853–859 1095 pp.
Avendaño M. (1993) Données de la biologie du pétoncle chilien Argopecten purpuratus. PhD thesis, Université de Bretagne Occidentale, Brest, France. 159 pp.
Bachelet G, Deprez M, Ducrotoy J.P, Guillou J, Labourg P.J, Rybarczyk H, Sauriau P.G, Elkaim B, Glémarec M. (1992) Rôle de la compétition intraspécifique dans la régulation du recrutement chez la coque, Cerastoderma edule (L.). Annales de l'Institut Océanographique, Paris 68:a75–87.
Bachelet G, Guillou J, Labourg P.J. (1992) Adult–larval and juvenile interactions in the suspension-feeding bivalve, Cerastoderma edule (L.): field observations and experiments. Annales de l'Institut Océanographique, Paris 68:75–87.
Barber B.J, Getchell R, Shumway S, Schick D. (1988) Reduced fecundity in a deep-water population of the giant scallop Placopecten magellanicus in the Gulf of Maine, USA. Marine Ecology Progress Series 42:207–212.[Web of Science]
Beaumont A and Budd M. (1983) Effects of self-fertilization and other factors on the early development of scallop Pecten maximus. Marine Biology 76:285–289.[CrossRef]
Beaumont A.R, Tserpes G, Budd M.D. (1987) Some effects of copper on the veliger larvae of the mussel Mytilus edulis and the scallop Pecten maximus (Mollusca Bivalvia). Marine Environmental Research 21:299–309.[CrossRef][Web of Science]
Beiras R and His E. (1995) Effects of dissolved mercury on embryogenesis, survival and growth of Mytilus galloprovincialis mussel larvae. Marine Ecology Progress Series 126:185–189.[Web of Science]
Berthou P. and Glémarec M. (1988) Distribution temporelle et spatiale des cohortes de Spisula ovalis (Sowerby) dans le nord du golfe de Gascogne: reflet d'une compétition inter-cohorte? ICES CM 1988/K: 35. 15 pp.
Blanco-Pérez J. (2001) Episodos nocivos for fitoplancton. In Maeda-Martinez A.N (Ed.). Los Moluscos Pectinidos de Iberoamérica: Ciencia y Acuicultura(Limusa, Noriega Editores, México) pp. 285–324 501 pp.
Boucher J and Dao J.C. (1990) Recrutement et forçage du recrutement de la coquille Saint-Jacques (Pecten maximus). In Troadec J.P (Ed.). L'homme et les Ressources Halieutiques(Editions IFREMER, Brest) pp. 313–354 354 pp.
Boucher J. and Fifas S. (1995) Dynamique de la population de coquilles St-Jacques (Pecten maximus) de la rade de Brest, hier était-il différent d'aujourd'hui? Actes de colloques, 3ièmes Rencontres Scientifiques Internationnales, Programme Rade de Brest vol. 2: pp. 2–12.
Brand A.R, Paul J.D, Hoogesteger J.N. (1980) Spat settlement of the scallops Chlamys opercularis (L.) and Pecten maximus on artificial collectors. Journal of the Marine Biological Association of the United Kingdom 60:379–390.[Web of Science]
Buestel D, Cochard J.C, Dao J.C, Gérard A. (1982) Production artificielle de naissain de coquilles Saint-Jacques Pecten maximus L. Premiers résultats en rade de Brest. Vie Marine 4:24–28.
Bull M.F. (1991) Fisheries and Aquaculture. New Zealand. In Shumway S.E (Ed.). Scallops: Biology, Ecology and Aquaculture(Elsevier, New York) pp. 853–859 1095 pp.
Burnell G. M. (1983) Growth and reproduction of the scallop Chlamys varia L. on the west coast of Ireland. PhD thesis, University College Galway, Ireland. 295 pp.
Caddy J. (1979) Long term trends and evidence for production cycles in the Bay of Fundy scallop fishery. Rapports et Procès-verbaux du Conseil International pour l'Exploration de la Mer 175:97–108.
Cantillanez M. (2000) Reproduction, vie larvaire et pré-recrutement du pectinidé Argopecten purpuratus (Lamarck, 1819) dans la baie d'Antofogasta (Chili). PhD thesis, Université de Bretagne Occidentale, Brest, France. 167 pp.
Carriker M.R. (1961) Interrelation of functional morphology, behaviour and autoecology in early stages of bivalve Mercenaria mercenaria. Journal of Elisha Mitchell Scientific Society 77:168–241.
Carriker M.R. (1988) Bivalve larval research, in transition: a commentary. Journal of Shellfish Research 7:11–6.
Casse N. (1995) Elément d'embryologie de Pecten maximus L. (Mollusque, Bivalve). PhD thesis, Université de Bretagne Occidentale, Brest, France 109 pp., 32 pl.
Chauvaud L. (1998) La coquille Saint-Jacques en Rade de Brest: un modèle biologique d'étude des réponses de la faune benthique aux fluctuations de l'environnement. PhD thesis, Université de Bretagne Occidentale, Brest, France. 265 pp.
Chevolot L, Cochard J.C, Yvin J.C. (1991) Chemical induction of larval metamorphosis of Pecten maximus with a note on the nature of naturally occurring triggering substances. Marine Ecology Progress Series 74:883–889.
Chia F.S, Buckland J, Young C.M. (1984) Locomotion of marine invertebrate larvae. Canadian Journal of Zoology 62:1205–1222.
Ciocco N.F and Orensanz J.M. (2001) Depredacion. In Maeda-Martinez A.N (Ed.). Los Moluscos Pectinidos de Iberoamérica: Ciencia y Acuicultura(Limusa, Noriega Editores, México) pp. 267–284 501 pp.
Claxton T.W and Boudling E.G. (1998) A new molecular technique to identify collections of Zebra Mussel (Dreissena polymorpha) and Quagga Mussel (Dreissena bugensis) veligers applied to Eastern Lake Erie, Lake Ontario and Lake Simcoe. Canadian Journal of Zoology 76:194–198.
Cochard J. C. and Gérard A. (1987) Production artificielle de naissain de coquille Saint-Jacques Pecten maximus (L.) en rade de Brest: analyse des facteurs affectant la croissance larvaire. Sixth International Pectinid Workshop9–14 April 1987Menai Bridge, Wales 12 pp.
Cochard J.C, Chevolot L, Yvin J.C, Chevolot-Magueur A.M. (1989) Induction de la métamorphose de la coquille Saint-Jacques Pecten maximus L. par des dérivés de la tyrosine extraits de l'algue Delesseria sanguinea Lamouroux ou synthétiques. Haliotis 19:129–154.
Comely C.A. (1972) Larval culture of the scallop Pecten maximus (L.). Rapports et Procès-verbaux du Conseil International pour l' Exploration de la Mer 34:3365–378.
Conan G and Shafee M.S. (1978) Growth and biannual recruitment of the black scallop Chlamys varia (L.) in Lanvéoc area, Bay of Brest. Journal of Experimental Marine Biology and Ecology 35:59–71.[CrossRef][Web of Science]
Cragg S.M. (1980) Swimming behaviour of the larvae of Pecten maximus (L.). Journal of the Marine Biological Association of the United Kingdom 60:551–564.[Web of Science]
Cragg S.M and Crisp D.J. (1991) The biology of scallop larvae. Development in aquaculture and fisheries science. In Shumway S.E (Ed.). Scallops: Biology, Ecology and Aquaculture(Elsevier, New York) pp. 75–132 1095 pp.
Culliney J.L. (1974) Larval development of giant scallop Placopecten magellanicus (Gmelin). Biological Bulletin 147:321–322.
Dadswell M. J., Chandler R. A., Parson G. J. (1987) Spat settlement and early growth of the giant scallop, Placopecten magellanicus in Pallamaquoddy Bay and the Bay of Fundy, Canada. Sixth International Pectinid Workshop9–14 April 1987Menai Bridge, Wales 11 pp.
Davis M, Hodgkins G.A, Stoner A.W. (1996) A mesocosm system for ecological research with marine invertebrate larvae. Marine Ecology Progress Series 130:97–104.[Web of Science]
Demers A, Lagadeuc Y, Dodson J.J, Lemieux R. (1993) Immunofluorescence identification of early life history stages of scallops (Pectinidae). Marine Ecology Progress Series 97:83–89.[Web of Science]
Desrosiers R.R, Désilets J, Dubé F. (1995) Early developmental events following fertilization in the giant scallop Placopecten magellanicus. Canadian Journal of Fisheries and Aquatic Sciences 53:1382–1392.
Dickie L.M. (1955) Fluctuation in abundance of the giant scallop, Placopecten magellanicus (Gmelin) in the Digby area of the Bay of Fundy. Journal of the Fisheries Research Board of Canada 12:6797–857.[Web of Science]
Dorange G, Paulet Y.M, Le Pennec M, Cochard J.C. (1989) Critères d'évaluation de la qualité des ovocytes émis par Pecten maximus (Mollusque Bivalve). Comptes Rendus de l'Académie des Sciences, Paris 309:III113–120.
Dwiono S. (1992) La métamorphose chez Pecten maximus (L.) (Mollusque Bivalve). PhD thesis. Université de Bretagne Occidentale, Brest, France. 80 pp., 32 pl.
Fotel F.L, Jensen N.J, Wittrup L, Hansen B.W. (1999) In situ and laboratory growth by a population of blue mussel larvae (Mytilus edulis L.) from a Danish embayment, Knebel Vig. Journal of Experimental Marine Biology and Ecology 233:2213–230.[CrossRef][Web of Science]
Freites L, Lodeiros A, Velez A, Bastardo J. (1993) Vibriosis en larvas de la vieira tropical Euvola (Pecten) zigzag L. Caribbean Journal of Science 29:89–98.
Garland E.D and Zimmer C.A. (2002) Techniques for the identification of bivalves larvae. Marine Ecology Progress Series 225:299–310.[Web of Science]
Gérard A, Salaün M, Tritar S. (1989) Critères de compétence des larves à la métamorphose chez Pecten maximus. Haliotis 19:373–380.
Golikov A.N and Scarlato O.A. (1970) Abundance, dynamics and production properties of populations of edible bivalves Mizuhopecten yessoensis and Spisula sachalinensis related to the problem of organization of controllable submarine farms at the western shores of the Sea of Japan. Helgoländer Wissenschaftliche Meeresuntersuchugen (Hamburg) 20:498–513.[CrossRef]
Gruffydd L.D and Beaumont A. (1970) Determination of the optimum concentration of eggs and spermatozoa for the production of normal larvae in Pecten maximus (Mollusca Lammellibranchia). Helgoländer Wissenschaftliche Meeresuntersuchungen (Hamburg) 20:486–497.[CrossRef]
Gruffydd L.D and Beaumont A. (1972) A method for rearing Pecten maximus in the laboratory. Marine Biology 15:350–355.[CrossRef]
Hancock D.A. (1973) The relationship between stock and recruitment in exploited invertebrates. Rapports et Procès-verbaux du Conseil International pour l'Exploration de la Mer 164:113–131.
Harvey M, Bourget E, Miron G. (1993) Settlement of Iceland scallop Chlamys islandica spat response to Hydroids and filamentous red algae: field observations and laboratory experiments. Marine Ecology Progress Series 99:283–292.[Web of Science]
Harvey M, Bourget E, Gagné N. (1997) Spat settlement of the giant scallop, Placopecten magellanicus (Gmelin, 1791), and other bivalve species on artificial filamentous collectors coated with chitinous material. Aquaculture 148:277–298.[CrossRef][Web of Science]
Hodgson C.A and Burke R.D. (1988) Developmental and larval morphology of the spiny scallop, Chlamys hastata. Biological Bulletin 174:303–318.
Illanes-Bucher J. E. (1987) Cultivation of the northern scallop of Chile (Chlamys (Argopecten) purpurata) in controlled and natural environments. Sixth International Pectinid Workshop9–14 April 1987Menai Bridge, Wales 8 pp.
Ito H. (1991) Fisheries and Aquaculture: JAPAN. Development in aquaculture and fisheries science. In Shumway S.E (Ed.). Scallops: Biology, Ecology and Aquaculture(Elsevier, New York) pp. 1017–1056 1095 pp.
Kaartvedt S, Aksnes D.L, Egge J.K. (1987) Effect of light on the vertical distribution of Pecten maximus larvae. Marine Ecology Progress Series 40:195–197.[Web of Science]
Kingzett B.C, Bourne N, Leask K. (1990) Induction of metamorphosis of the Japanese scallop Patinopecten yessoensis (Jay). Journal of Shellfish Research 9:1119–124.
Krauter J.N, Castagna M, Van Dessel R. (1982) Egg size and larval survival of Mercenaria mercenaria (L.) and Argopecten irradians (Lamarck). Journal of Experimental Marine Biology and Ecology 56:3–8.[CrossRef][Web of Science]
Lambert C. (1998) Etude des infections à vibronaceae chez les mollusques bivalves, à partir d'un modèle de larves de Pecten maximus. PhD Thesis. Université de Bretagne Occidentale, Brest. 181 pp.
Lambert C, Nicolas J.L, Cilia V, Corre S. (1998) Vibrio pectenicida sp. nov. A pathogen of scallop (Pecten maximus) larvae. International Journal of Systematic Bacteriology 48:481–487.
Langthon R.W, Robinson W.E, Schick D. (1987) Fecundity and reproductive effort of sea scallop Placopecten magellanicus from the gulf of Maine. Marine Ecology Progress Series 37:19–25.[Web of Science]
Leibovitz L. (1989) Chlamydiosis: a newly reported disease of larval and post-metamorphic bay scallops, Argopecten irradians. Journal of Fish Disease 12:125–136.[CrossRef]
Le Pennec M. (1974) Morphogenèse de la coquille de Pecten maximus (L.) élevé au laboratoire. Cahiers de Biologie Marine 15:475–482.[Web of Science]
Le Pennec M. (1997) Les écloseries de mollusques bivalves: mode d'emploi. Bulletin of the Aquaculture Association of Canada 97-3:31–37.
Le Pennec M and Rangel-Davalos C. (1985) Observations by epifluorescence microscopy of ingestion and digestion of unicellular algae by young larvae of Pecten maximus Pectinidae Bivalvia. Aquaculture 47:39–52.[CrossRef][Web of Science]
Le Pennec M, Guéguen F, Cochard J.C, Paulet Y.M, Dorange G. (1990) Relations entre le contenu lipidique des ovocytes de Pecten maximus (Mollusque Bivalve) et les performances des larves en élevage. Haliotis 10:101–103.
Le Pennec M, Robert R, Avendaño M. (1998) The importance of gonadal development on larval production in pectinids. Journal of Shellfish Research 17:97–101.[Web of Science]
Liao C and Li Y. (1980) Influence of Sheng-Li crude oil on early development of scallop Chlamys farreri (Jones et Prestois). Journal of Shandong College of Ocean 10:52–59.
Loosanoff V.L and Davis H.C. (1963) Rearing of bivalve mollusks. In Russell F.S (Ed.). Advances in Marine Biology(Academic Press, London/New York) 136 pp.
Lubet P, Besnard J.Y, Faveris R, Robbins I. (1987) Physiologie de la reproduction de la coquille Saint-Jacques (Pecten maximus L.). Océanis 3:13265–290.
Lucas A, Chebab-Chalabi L, Aldana-Aranda D. (1986) Passage de l'endotrophie à l'exotrophie chez les larves de Mytilus edulis. Oceanologica Acta 9:1191–196.[Web of Science]
Manahan D.T and Crisp D.J. (1983) Autoradiographic studies on the uptake of dissolved amino acids from sea water by bivalve larvae. Journal of the Marine Biological Association of the United Kingdom 63:673–682.[Web of Science]
Maru K. (1976) Studies on the reproduction of a scallop, Patinopecten yessoensis (Jay). 1. Reproductive cycle of the cultured scallop. Scientific Report of the Hokkaïdo Fisheries Experimental Station 18:9–25.
Mestre S. (1992) Ciclo gametogénetico y de almaceniamento de reservas en una poblacion natural de Pecten jacobeus (L.) (Bivalvia: Pectinidae) en las costas de Castellon. PhD thesis, Universidad de Valencia, España. 411 pp.
Mileikovsky S.A. (1971) Types of larval development in marine bottom invertebrates, their distribution and ecological significance: a re-evaluation. Marine Biology 10:193–213.[CrossRef]
Mileikovsky S.A. (1974) On predation of pelagic larvae and early juveniles of bottom invertebrates by adult benthic invertebrates and their passing alive though their predators. Marine Biology 26:303–311.[CrossRef]
Minchin D. (1985) Possible effects of an intense algal bloom of Gyrodinium aureolum on a year class of scallops (Pecten maximus). Fifth International Pectinid Workshop6–10 May 1985La Coruña, Spain 14 pp.
Minchin D, Duggan C.B, King W. (1987) Possible effect of organotins on scallop recruitment. Marine Pollution Bulletin 18:604–608.[CrossRef][Web of Science]
Moyer M. A. and Blake N. J. (1986) Fluctuations in calico production (Argopecten gibbus). Proceedings of the 11th Annual Tropical and Subtropical Fisheries Conference of the AmericasTexas Agricultural Extension Service, Texas A & M University pp. 45–58.
Naidu K.S. (1991) Development in aquaculture and fisheries science. In Shumway S.E (Ed.). Scallops: Biology, Ecology and Aquaculture(Elsevier, New York) pp. 861–898 1095 pp.
Navarte M.A, Félix-Pico E, Ysla-Chee L. (2001) Asentamiento larvario de Pectinidos, en colectores artificiales. In Maeda-Martinez A.N (Ed.). Los Moluscos Pectinidos de Iberoamérica: Ciencia y Acuicultura(Limusa, Noriega Editores, México) pp. 173–192 501 pp.
Nicolas L. (1999) Etude sur la métamorphose et le développement post-larvaire de la coquille St-Jacques, Pecten maximus, en écloserie. PhD thesis, Université de Bretagne Occidentale, Brest, France. 224 pp.
Nicolas L, Robert R, Chevolot L. (1998) Comparative effect of inducers on metamorphosis of the Japanese oyster Crassostrea gigas and the great scallop Pecten maximus. Biofouling 12:1–3189–203.[Web of Science]
Orensanz J.M. (1986) Size, environment, and density: the regulation of a scallop stock and its management implications. Canadian Special Publication of the Fisheries Aquatic Sciences 92:195–227.
Patwary M.U, Kenchington E.L, Bird C.J, Zouros E. (1994) The use of random amplified polymorphic DNA markers in genetic studies of the sea scallop Placopecten magellanicus (Gmelin, 1791). Journal of Shellfish Research 13:2547–553.[Web of Science]
Paugam A, Le Pennec M, André-Fontaine G. (2000) Immunological recognition of marine bivalve larvae from plankton. Journal of Shellfish Research 19:1325–331.[Web of Science]
Paulet Y.M, Lucas A, Gérard A. (1988) Reproduction and larval development in two Pecten maximus L. from Brittany. Journal of Experimental Marine Biology and Ecology 119:145–156.[CrossRef][Web of Science]
Paulet Y.M and Fifas S. (1989) Etude de la fécondité potentielle de la coquille Saint-Jacques Pecten maximus, en baie de Saint-Brieuc. Haliotis 19:275–285.
Paulet Y.M, Dorange G, Cochard J.C, Le Pennec M. (1992) Reproduction et recrutement chez Pecten maximus L. Annales de l'Institut Océanographique, Paris 68:1–245–64.
Paulet Y.M, Bekhadra F, Devauchelle N, Donval A, Dorange G. (1997) Cycles saisonniers, reproduction et qualité des ovocytes chez Pecten maximus en rade de Brest. Annales de l'Institut Océanographique, Paris 73:1101–112.
Prieur D. (1981) Experimental studies of trophic relationships between marine bacteria and bivalve molluscs. Kieler Meeresforschung 5:376–383.
Rabby D, Lagadeuc Y, Dodson J.J, Mingellbier M. (1994) Relationship between feeding and vertical distribution of bivalve larvae in stratified and mixed waters. Marine Ecology Progress Series 103:275–284.[Web of Science]
Riquelme C, Hayashida G, Toranzo A.E, Vilches J, Chavez P. (1995) Phatogenicity studies on a Vibrio anguillarum-related (VAR) strain causing an epizootic in Argopecten purpuratus larvae cultured in Chile. Disease of Aquatic Organisms 22:135–141.
Robert R, Miner P, Mazurier M, Connan J.P. (1994) L'écloserie expérimentale d'Argenton. Bilan et perspectives. Equinoxe 50:19–31.
Robert R and Gérard A. (1999) Bivalve hatchery technology: the current situation for the Pacific oyster Crassostrea gigas and the scallop Pecten maximus in France. Aquatic Living Resources 12:2121–130.[CrossRef][Web of Science]
Rumrill S.S. (1990) Natural mortality of marine invertebrate larvae. Ophelia 32:1–2163–198.[Web of Science]
Salaün M. (1994) La larve de Pecten maximus, genèse et nutrition. PhD thesis, Université de Bretagne Occidentale, Brest, France. 242 pp.
Salaün M, Boucher J, Le Pennec M. (1991) Prodissochonch shell characteristics as indicators of larval growth and viability in Pecten maximus (L.). Journal of Shellfish Research 10:137–46.
Sastry A.N. (1966) Temperature effects in reproduction of the bay scallops, Aequipecten irradians Lamarck. Journal of the Marine Biological Association of the United Kingdom 130:118–134.
Scheltema R.S. (1971) Dispersal of phytoplanctotrophic shipworm larvae (Bivalvia: Terenidae) over long distance by ocean currents. Marine Biology 11:5–11.[CrossRef]
Stanley C. A. (1967) The commercial scallop Pecten maximus in Northern Irish waters. PhD thesis, Queen's University of Ireland, Belfast, Ireland. 252 pp.
Stoz W and Mendo J. (2001) Pesquerias, repoblamiento y manejo de bancos naturales de Pectinidos en Iberoamérica: su interaccion con la acuicultura. In Maeda-Martinez A.N (Ed.). Los Moluscos Pectinidos de Iberoamérica: Ciencia y Acuicultura(Limusa, Noriega Editores, México) pp. 357–374 501 pp.
Strathmann R.S. (1979) Egg size, larval development and juvenile size in benthic marine invertebrates. American Naturalist 111:373–376.
Thompson R.J. (1977) Blood chemistry, biochemical composition, and the annual reproductive cycle in the giant scallop, Placopecten magellanicus, from Southeast Newfoundland. Journal of Fisheries Research Board of Canada 34:2104–2116.
Thorson G. (1950) Reproductive and larval ecology of marine bottom invertebrates. Biological Reviews 25:1–45.[Medline]
Thorson G. (1996) Some factors influencing the recruitment and establishment of marine benthic communities. Netherlands Journal of Sea Research 3:2267–293.
Thouzeau G and Lehay D. (1988) Variabilité spatio-temporelle de la distribution, de la croissance et de la survie des juvéniles de Pecten maximus (L.) issus des pontes 1985, en baie de Saint Brieuc. Oceanologica Acta 11:267–283.[Web of Science]
Tremblay M.J and Sinclair M.M. (1988) The vertical and horizontal distribution of sea scallop (Placopecten magellanicus) larvae in the bay of Fundy in 1984 and 1985. Canadian Journal of Fisheries and Aquatic Sciences 44:71361–1366.
Tremblay M.J and Sinclair M.M. (1990) Sea scallop larvae Placopecten magellanicus on Georges Bank: vertical distribution in relation to water column stratification and food. Marine Ecology Progress Series 61:1–15.[Web of Science]
Tremblay M.J, Loder J.W, Werner F.E, Naimie C.E, Page F.H, Sinclair M.M. (1994) Drift of sea scallop larvae Placopecten magellanicus on Georges bank: a model study of the roles of mean advection, larval behaviour and larval origin. Deep Sea Research II 41:17–50.[CrossRef]
Tritar S and Lucas A. (1989) Remarques méthodologiques sur le calcul du taux de fixation chez les bivalves en métamorphose. Haliotis 19:251–257.
Tritar S, Prieur D, Weiner R. (1992) Effects of bacterial films on the settlement of oysters, Crassostrea gigas (Thunberg, 1793) and Ostrea edulis (Linnaeus, 1750) and the scallop Pecten maximus (Linnaeus, 1758). Journal of Shellfish Research 11:2325–330.
Uriarte I, Rupp G, Abarca A. (2001) Produccion de juveniles de Pectinidos iberoamericanos bajo condiciones controladas. In Maeda-Martinez A.N (Ed.). Los Moluscos Pectinidos de Iberoamérica: Ciencia y Acuicultura(Limusa, Noriega Editores, México) pp. 147–172 501 pp.
Uribe E., Solar C., Vicuna C., Green J. (1994) Induction of metamorphosis of the Chilean scallop Argopecten purpuratus (Lamar). Ninth International Pectinid Workshop22–27 April 1993Nanaimo, Canada 6 pp.
Vahl O. (1982) Long term variation in recruitment of the Iceland scallop, Chlamys islandica (O.F. Müller), from Northern Norway. Netherlands Journal of Sea Research 16:80–87.
Ventilla R.F. (1982) The scallop industry in Japan. Advance in Marine Biology 20:309–382.
Verdier-Bonnet C, Carlotti F, Rey C, Bhaud M. (1997) A model of larval dispersion coupling wind-driven currents and vertical larval behaviour: application to the recruitment of the annelid Owenia fusiformis in Banyuls Bay, France. Marine Ecology Progress Series 160:217–231.[Web of Science]
Wolff M. (1988) Spawning and recruitment in the Peruvian scallop Argopecten purpuratus. Marine Ecology Progress Series 42:213–217.[Web of Science]
Woodin S.A. (1976) Adult–larval interactions in dense infaunal assemblage: patterns of abundance. Journal of Marine Research 34:25–41.[Web of Science]
Wright D.A, Kennedy V.S, Roosenberg W.H, Castagna M, Mihursky J.A. (1983) Temperature tolerance of embryos and larvae of five bivalve species under simulated power entrainment conditions: a synthesis. Marine Biology 77:271–278.[CrossRef]
Wright D.A, Roosenberg W.H, Castagna M. (1984) Thermal tolerance in embryos and larvae of the bay scallop Argopecten irradians under simulated power plant entrainment conditions. Marine Ecology Progress Series 14:269–273.[Web of Science]
Yamamoto G. (1960) Mortalities of the scallop during its life cycle. Bulletin of the Marine Biological Station of Asamushi X:2149–152.
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