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Brooding pattern and larval production in wild stocks of the puelche oyster, Ostrea puelchana d'orbigny.

ABSTRACT Brooding pattern and fertility of the puelche oyster (Ostrea puelchana) were investigated in a native population from the San Matias Gulf (40[degrees]48'S; 65[degrees]05'W, Northern Patagonia, Argentina). Monthly samples of 100 oysters were randomly collected at the oyster ground during the period November 1999 to January 2000, and weekly in the 2000 to 2001 reproductive season. Complementary data were obtained from the literature (1976 to 1978) and samplings performed during the periods 1980 to 1984 and 1987 and 1998. The date at which oysters begin larval brooding may be placed somewhere within the period November 18 to January 11. In most seasons (77%), brooding starts within the period November 18 to December 5. The number of brooders is low at the debut (7.5% in 1999, 4% in 2000), peaking at the end of spring (20%), and gradually decreasing until reaching nearly 1% by middle February. Total number of larvae brooded on each sampling date showed a high correlation with brooding percentages ([r.sup.2] = 0.85). Mean fertility showed no correlation with the percentage of oysters brooding larvae ([r.sup.2] = 0.12). The highest value of mean fertility (2.7 million) was recorded at the beginning of the season when 4% of the oysters were brooding larvae. Mean fertility ranged from 900,000 to 2,700,000 larvae. Brood size ranges from 447,500 to 3,790,000 larvae (mean = 1,868,212; s = 813,808; n = 121). Individual fertility showed no correlation with neither size (total height) nor with internal volume of oysters within a size range of 60-115 mm. O. puelchana shows the highest fertility recorded in Ostrea species, a feature that seems consistent with its short incubation period, small egg size, long planktonic life, and small size of pediveligers.

KEY WORDS: oysters, Ostrea puelchana, brooding, larval production


The puelche oyster, Ostrea puelchana, is a commercially valuable flat oyster species native to temperate waters of the San Matias Gulf (Northern Patagonia, Argentina). As with all other Ostrea species, O. puelchana broods the larvae and releases them as veligers, in this particular case after 6-7 days of incubation and at an initial size of 110-130 [micro]m (Pascual & Zampatti 1995).

This species has received a great amount of research effort clue to the biologic interest in its peculiar reproductive feature of "carriage" of epibiotic dwarf males (Calvo & Morriconi 1978, Fernandez Castro & Lucas 1987, Pascual et al. 1989, Pascual 1997, Pascual 2000). The commercial interest in its culture (Pascual & Bocca 1988, Pascual & Zampatti 1995) generated the oyster culture project that has been developed in Northern Patagonia since 1980.

Hatchery seed of this species was produced for the first time in France in 1988 (Pascual et al. 1991 ICES, Pascual & Zampatti 1995). Routine seed production in Argentina has been performed since 1997 in the state hatchery of Rio Negro Province.

From 1997 to 2003 research efforts were focused on reproductive studies and the application of the acquired knowledge on the improvement of broodstock conditioning to increase larval production.

As is the case with other flat oyster species (Perez Camacho 1987), hatchery seed production of the Puelche oyster has been constrained by the relatively low amount of larvae released by each individual oyster (fertility). Thus a large number of animals for broodstock conditioning in the hatchery is required. In consequence a detailed knowledge of brooding behavior in natural conditions is necessary to design a correct management plan for seed production.

In this study we present results gathered for several years, particularly in 2000 and 2001, regarding the annual pattern of brooding and larval production in Puelche oysters from one of the main natural oyster grounds of Northern Patagonia.


Condition Index of the Parental Stock

Monthly samples of 40 oysters of sizes ranging from 65-95 mm (total height) were randomly collected by scuba diving at the oyster ground of Las Grutas (40[degrees]48'S; 65[degrees]05'W; Fig. 1) during the period June 1997 to September 1998. Seawater temperature was recorded on each collection date.


Total height and length was recorded for each oyster. Internal volume was estimated in the following way: each live oyster was hang tied by a thread and sunk into a beaker filled with seawater and placed on a balance. Total live weight and shells weight were registered by this method, and internal volume (IV) was calculated as the difference between both weights. Condition index was calculated as: CI = IV/DMW x 100. Dry meat weight (DMW) was recorded a posteriori.

Brooding Pattern

A hundred oysters of size ranging from 60-100 mm (total height) were haphazardly collected on each sampling date from the population of Las Grutas (Fig. 1). Sampling was performed monthly during the 1999 to 2000 season (November, December, and January). In the 2000 to 2001 season, sampling frequency was increased and the collections were performed weekly (November to February) to assure an accurate coverage of brooding dynamics (brooding period lasts 5-7 days in this species, Pascual & Zampatti 1995).

Shell height and live weight were recorded before the oysters were opened. For brooding oysters, larvae were removed by gently washing the oysters with a spray bottle over a 1 L graduated beaker filled with seawater. Total number of larvae per oyster (fertility) was estimated by counting larvae--under a stereomicroscope--on 6 samples (100 [micro]L) collected with an Epphendorf pipette from the previously homogenized larval solution.

Internal volume of each sampled oyster was estimated using the method described earlier.

Complementary data on incubation dates and fertility were obtained from the literature (1976 to 1978, Morriconi & Calvo 1980) and from samplings performed during the periods 1980 to 1984 (Parma & Pascual, unpubl, data), 1987 (Zampatti, unpubl, data), and 1998 (Castanos, unpubl.).


Reproductive Behavior of Puelche Oysters in the Natural Ground

Condition Index of Parental Stock

Seawater temperature and condition index (CI) are inversely correlated throughout the year (Fig. 2). Minimal temperatures are recorded in July to August (6[degrees]C to 8[degrees]C), and maximal temperatures are recorded in December to January (19[degrees]C to 20[degrees]C). CI starts decreasing in December and reaches its minimal value in February (7.88). During autumn and winter CI gradually increases until reaching its maximal values during the period August to November (14.5-14.7).


Brooding Pattern

The beginning of larval brooding in natural oyster populations of the San Matias Gulf, registered over 13 y, occurs within the period November 18 to January 11 (Fig. 3). In most seasons (77%), brooding starts within the period November 18 to December 5. Even when there were some gaps in seawater temperature records, the available data suggest that brooding has a threshold temperature of 16[degrees]C, even when interannual fluctuations occur within a range of 16[degrees]C to 20[degrees]C.


Sampling design carried out in 1999 and, the more detailed one carried out in the 2000 to 2001 season, enabled the study of brooding behavior at two different seasons.

In 1999, brooding started early in the season, on November 18, with a low percentage of brooders in the population (7.5%). The three samplings carried out in 1999 showed a peak in the number of brooders in the population and in the total larval production by early December (12/5: 12% of brooders and 31.9 millions larvae). This value decreased at the beginning of the summer (January 5: 12 million larvae and 6% of brooding).

In 2000 brooding was delayed compared with the previous season, starting on December 4 with only a 4% of the oysters brooding larvae (Fig. 4). The percentage of brooders steadily increased afterwards, peaking on December 21 (20%). One week later, on December 28, the percentage of brooders abruptly fell to 6.7%, increasing again afterwards to 15%. Brooding numbers gradually decreased from January 12 until reaching a minimum of 1% by middle February (Fig. 4a).


Mean fertility (mean number of larvae incubated per oyster), all dates considered, ranged from 900,000 to 2,700,000 larvae (Fig. 4a). Mean fertility showed no correlation with the percentage of oysters brooding larvae at each date ([r.sup.2] = 0.12). In 2000, however, the highest values of mean fertility (2.7 and 2.5 million larvae) were recorded at the beginning of the season (December 4 and 12) when 4% and 13% of the oysters were brooding larvae (Fig. 4a).

Total number of larvae brooded (total larval production) on each sampling date along the season showed a high correlation with brooding percentages ([r.sup.2] = 0.85) being the highest value found on December 21 (Fig. 4b).

Individual fertility estimates show that Puelche oysters may brood from 447,500 to 3,790,000 larvae (mean = 1,868,212; std = 813,808; n = 121). Individual fertility did not show any correlation neither with size (total height) nor with internal volume of oysters within a size range of 60-115 mm.


Phylogenetic relations among brooding oysters have been the matter of controversial discussions. Harry (1985) published a polemical paper presenting a morphologically based reclassification of flat oysters. Perhaps the most controversial point was the case of the Southern Hemisphere species. Harry (1985) synonymized several species as Ostrea puelchana: O. chilensis Philippi (Chile and New Zealand), O. angassi Sowerby (Australia), and O. algoensis Sowerby (South Africa). Jozefowicz and O'Foighil (1998) performed a comprehensive molecular phylogenetic analysis on ostreinid taxa. Their main goal was to determine if flat oysters occurring between latitudes 35[degrees]S and 50[degrees]S constituted a single circumglobal species or distinct regional taxa. Among other very conclusive remarks, the authors point out that the molecular data together with other distinctions undermine Harry' s (1985) assumption that O. puelchana has a circumglobal distribution beneath 35[degrees]S. They recommend retaining the original names for Southern Hemisphere taxa: O. puelchana, O. angasi, O. chilensis, and O. algoensis.

Jozefowicz and O'Foighil (1998) also pointed out that if it were true, the fact that genomic mutation rates are proportional to the relative frequency of germline cell divisions (Shimmin et al. 1993, Liu et al. 1996), the low fecundity of Ostrea species could explain the low genetic divergence levels found among them, compared with those of highly fecund cupped oysters from America and Asia. This same conclusion was reached earlier by Buroker (1985) who, additionally compared several Ostrea species and suggested that Tiostrea chilensis Philippi, the species that best characterizes the "Ostrea type;" has lower genetic variation than other Ostrea like O. permollis or O. lurida Carpenter, which tend to be more closely aligned to nonbrooding species.

In this regard, the fertility of O. puelchana is strikingly high compared with the available information recorded for other Ostrea species (Table 1), its mean value doubling the highest value recorded for Ostreas corresponding to the European oyster; Ostrea edulis Linnaeus releases 9.57 x [10.sup.5] larvae (Cole 1941, Walne 1964).

There seems to be a gradient in several life history traits such as incubation period, egg size, duration of planktonic life, and size of pediveligers. In this gradient O. puelchana can be placed in one extreme with the highest fertility recorded, a feature that seems consistent with its short incubation period, small egg size, long planktonic life, and small size of pediveligers. O. chilensis may be placed in the opposite extreme of the gradient regarding these same traits (Table 1).

Mean fertility in Puelche oysters decreases from its initial and highest value (2.7 million larvae per oyster) recorded in the end of spring to its lowest value (1.1 million larvae) registered at the end of the reproductive season.

Detailed research on the reproductive biology of the Puelche oyster (Castanos, unpublished) gives support to this behavior because the majority of oysters spawning as females at the debut of the season show a much more intense gonad development than those spawning as females late in the season, following a first and intense male spawning.

This data match those of Cerruti (1941) who estimated that late spawners of O. edulis spawned one-third to one-sixth the number of eggs produced by those oysters spawning early in the season. The same behavior and explanation was offered by Cole (1941) and Korringa (1952) for O. edulis, even when Walne (1964) studying the same species could not find evidence of this behavior.

Cranfield and Allen (1977) for O. lutaria Hutton, from New Zealand found that even when fertility varied widely in the different sampling periods; there was no consistent seasonal trend in this variation as was previously suggested by Hollis (1963).

Jeffs et al. (1996) studied the brooding behavior of Tiostrea chilensis Philippi in Northern New Zealand and suggested that in this year-round brooder, larger broods seem to be associated with increasing levels of brooding activity and lower water temperatures. Despite year-round brooding, the proportion of the population brooding during peak periods remained comparable to the highest proportions reported for populations elsewhere with shorter brooding seasons.

Hopkins (1936) suggested that, for O. lurida Carpenter (Northeast Pacific), the higher number of brooders appear within a period of about 6 wk at the beginning of the spawning season, though occasionally gravid individuals may be found during the following 5 or 6 mo. A secondary wave of spawning may occur later in the season.

Cole (1941) found a positive correlation between parent size and brood size in O. edulis.

This same relationship was found by Hopkins (1937) in O. lurida. However, oysters of the same length show a great variation in brood size suggesting that length is probably not a good criterion and that perhaps volume of the meat or fatness, on which reproductive capacity probably depends, may vary considerably and could better explain the relation.

In the case of O. edulis, an oyster almost doubles its capacity (fertility) each year, until the fourth year of life when fertility stabilizes in its definitive value (Cole 1941). In several incubating oysters, a relation can be found between size, weight, meat volume, and brood size (Walne 1964, Jeffs et al. 1997a, Jeffs et al. 1997b, Cranfield & Allen 1977).

Morriconi and Calvo (1980) suggested that in O. puelchana fertility (specially if it is measured as number of embryos per brooder) increases with size and dry meat weight. Our data could not confirm this result suggesting that fertility increases neither with size nor with the internal volume of the oyster. A more detailed study should be performed to make this point clear taking special care on the fact that we are looking at a sequential hermaphrodite that alternates sexual phases and shows differences in the intensity of female gonad development depending not only on size but also on the time of the season this sexual phase becomes functional. This same observation was made by Cole (1941) who suggested that the relation between fertility and size might be obscured by the time in the season.

The compiled experience suggests that conclusions can only be driven once a deep knowledge is acquired on the reproduction of each particular species.

Chaparro et al. (1993) describes the behavior of O. chilensis larvae within the mother's brooding chamber. They also discussed the energy costs of brooding suggesting that, because larvae actually feed during their long incubation period (8 wk), the female may increase its clearance rate so as to compensate for the retention of particles by the larvae. This cost, summed to the cost in generating the currents that transport the larvae through the pallial cavity should be possibly measured. Our own unpublished observations, however, suggest that brooding Puelche oysters decrease their filtration rate by reducing the degree to which they open their valves, perhaps a behavior meant to prevent larvae loss.

In fact, brooding oysters show extremely low filtration rates compared with nonbrooding oysters (Castanos, unpublished). This preliminary observation suggests that at least in the case of O. puelchana, brooding probably does not imply an extra energetic cost. This may be consistent with the short brooding period in this species (5-7 days, Pascual & Zampatti 1995) during which the small larvae may grow fueled only by egg reserves. This fact could be backed by the behavior of the condition index, which decreases abruptly from November to December, coincidently with male and female spawning.

Jeffs et al. (1996) conclude from their study on the annual cycle of brooding and fertility in T. chilensis that the shortage of spat in hatcheries is related to the brooding dynamics of this species. There have been continuous difficulties in developing a hatchery technique for conditioning and synchronizing larval production in Tiostrea broodstock. They recommend water temperature manipulation as the most fruitful area for research aimed to improve larvae hatchery production.

The Puelche oyster seems to be an exception in this regard due to its high fertility that enables an easy hatchery manipulation and a high larval production based on a relatively small broodstock. The biologic knowledge acquired, related to the reproductive behavior of this species, has been the key for a successful seed production program of this species.
Life history traits recorded for several Ostrea species.

 No. of
 Brooding Brooders
Species Locality Pattern (%)

Ostrea edulis England May to Sept. 13-20.6

Ostrea chilensis Chile Nov. to Jan. 12-48

=0. lutaria Northern New Zealand Year-round 18.2

=T. chilensis Central and Southern Aug. to March 2.6-5.6
 New Zealand

Ostrea lurida Washington St., May to Aug. 55
 Columbia, Canada,
 California, USA

Ostrea permollis Florida, USA

Ostrea puelchana San Matias Gulf Nov. to Feb. 20

Ostrea equestris Georgia, USA Apr. to Oct. 3.1

Ostrea spreta San Matias Gulf Dec. to Feb. 13.3

Ostrea aupouria Northern New Zealand Dec. to May

Ostrea angasi Tasmania, Australia Nov. to Feb. 16 (in 2 mo)

 Days of
 Days of Planktonic Egg Size
Species Incubation Life ([micro]m)

Ostrea edulis 7-10 10 150

Ostrea chilensis 21-56 5 min-48 h 220-323

=0. lutaria 264-323

=T. chilensis 25-30 Some minutes 280

Ostrea lurida 10 7(24[degrees]C) 100-110
Ostrea permollis 7-9 30-33 70

Ostrea puelchana 5-7 17-20 60-90

Ostrea equestris

Ostrea spreta 22-30

Ostrea aupouria 10-15

Ostrea angasi 12-20

 Size of Larval
 Released Size at Fertility
 Larvae Settlement (Larvae
Species ([micro]m) ([micro]m) x 105)

Ostrea edulis 180-190 300 4.1-9.57

Ostrea chilensis 390-541 470-556 0.5-0.6

=0. lutaria 448-556 0.5-0.6

=T. chilensis 394-541 0.5

Ostrea lurida 165-189 250-325 2.15-3

Ostrea permollis 108-127 290 2.21

Ostrea puelchana 110-130 284 19

Ostrea equestris

Ostrea spreta 123 320

Ostrea aupouria 125-140 270-320

Ostrea angasi 186-203 300-320 0.3-15.2

Species Author(s)

Ostrea edulis Orton 1927, Cole 1941
 Korringa 1952, Walne
 1964, Wilson & Simons
 1985, Millican & Helm

Ostrea chilensis Walne 1963, Solis 1967
 DiSalvo et al. 1983, Winter
 et al. 1983, Toro &
 Chaparro 1990, Chaparro
 et al. 1993

=0. lutaria Jeffs et al. 1996, 1997a,

=T. chilensis Hollis 1963, Cranfield &
 Allen 1977, Cranfield &
 Michael 1989

Ostrea lurida Hori 1933
 Hopkins 1936, 1937
 Loosanoff & Davis 1963
 Coe 1932

Ostrea permollis Forbes 1966

Ostrea puelchana Calvo & Morriconi, 1980,
 Pascual & Zampatti 1995
 This work

Ostrea equestris Gutsell 1926, Menzel 1955
 Walker & Power 2001

Ostrea spreta Zampatti (unpubl.)

Ostrea aupouria Dinamani 1981

Ostrea angasi Sumner 1972, Dix 1976


The authors thank the International Foundation for Science (Grant A-704 to MP) and the Agencia Nacional de Promocion Cientifica y Tecnologica (PICT98#4221) for financial support.


Buroker, N. E. 1985. Evolutionary patterns in the family Ostreidae: laviparity vs. oviparity. J. Exp. Mar. Biol. Ecol. 90:233-247.

Calvo, J. & E. R. Morriconi. 1978. Epibiontie et protandrie chez Ostrea puelchana. Haliotis 9:85-88.

Cerruti, A. 1941. Osservazioni ed esperimenti sulle cause di distruzione delle larve dostrica nel Mar Piccolo e nel Mar Grande di Taranto. Arch. di Oceanogr. Limnol. Roma 1:165-201.

Chaparro, O. R., R. J. Thompson & J. E. Ward. 1993. In vivo observations of larval brooding in the Chilean Oyster, Ostrea chilensis Philippi, 1845. Biol. Bull. 185:365-372.

Coe, W. 1932. Development of the gonads and the sequence of the sexual phases in the California oyster (Ostrea lurida). Bull. Scripps Inst. of Oceanography, Univ. of Calif. Technical Series 3:119-144.

Cole, H. A. 1941. The fecundity of Ostrea edulis. J. Mar. Biol. Assoc. UK. 25:243-260.

Cranfield, H. J. & R. L. Allen. 1977. Fertility and larval production in an unexploited population of oysters, Ostrea lutaria Hutton, from Foveaux Strait. New Zealand Journal of Marine and Freshwater Research 11:239-253.

Cranfield, H. J. & K. P. Michael. 1989. Larvae of the incubatory oyster Tiostrea chilensis (Bivalvia, Ostreidae) in the plankton of central and southern New Zealand. New Zealand Journal of Marine and Freshwater Research 23:51-60.

Dinamani, P. 1981. Description of a new species of incubatory oyster from northern New Zealand, with notes on its ecology and reproduction. New Zealand Journal of Marine and Freshwater Research. 15:109-119.

DiSalvo, L. H., E. Alarcon & E. Martinez. 1983. Induced spat production from Ostrea chilensis Philippi 1845 in mid-winter. Aquaculture 30: 357-362.

Dix, T. 1976. Laboratory rearing of larval Ostrea angasi in Tasmania, Australia. J. Malac. Soc. Aust. 3(3-4):209-214.

Fernandez Castro, N. & A. Lucas. 1987. Variability in the frequency of male neoteny in Ostrea puelchana (Mollusca: Bivalvia). Mar. Biol. 96:359-365.

Forbes, M. L. 1966. Life Cycle of Ostrea permolis and its relationship to the host sponge, Stelletta grubii. Bull. Mar. Sci. 16:273-301.

Gutsell, J. S. 1926. A hermafroditic viviparous oyster of the Atlantic coast of North America. Science, vol LXIV. p. 450.

Harry, H. 1985. Synopsis of the supraspecific classification of living oysters (Bivalvia: Gryphaeidae and Ostreidae). The Veliger 28:121-158.

Hollis, P. J. 1963. Some studies on the New Zealand oysters. Zoology Publications from Victoria University of Wellington 31:1-28.

Hopkins, A. E. 1936. Ecological observations on spawning and early larval development on the Olympia oyster (Ostrea lurida). Ecology 17:551-556.

Hopkins, A. E. 1937. Experimental observations on spawning, larval development, and setting in the Olympia oyster, Ostrea lurida. US. Bureau of Fisheries. Bulletin No. 23:439-503.

Hori, J. 1933. On the development of the Olympia oyster, Ostrea lurida Carpenter, transplanted from United States to Japan. Bull. Jap. Soc. Sci. Fish. 1:269-276.

Jeffs, A. G., R. G. Creese & S. H. Hooker. 1996. Annual pattern of brooding in populations of Chilean oysters, Tiostrea chilensis, (Philippi, 1845) from Northern New Zealand. J. Shellfish Res. 15:617-622.

Jeffs, A. G., R. G. Creese & S. H. Hooker. 1997a. The potential for Chilean oysters, Tiostrea chilensis (Philippi, 1845), from two populations in northern New Zealand as a source of larvae for aquaculture. Aquacult. Res. 28:433-441.

Jeffs, A. G., S. H. Hooker & R. G. Creese. 1997b. Variability in life history characters of the Chilean oyster Tiostrea chilensis (Philippi, 1845). New Zealand Journal of Marine and Freshwater Research 31:487-495.

Jozefowicz, C. J. & D. O'Foighil. 1998. Phylogenetic analysis of southern hemisphere flat oysters based on partial mitochondrial 16S rDNA gene sequences. Molecular Phylogenetics and Evolution 10:426-435.

Korringa, P. 1952. Recent advances in oyster biology. The Quarterly Review of Biology 27:266-365.

Liu, H. P., J. B. Mitton & S. K. Wu. 1996. Paternal mitochondrial DNA differentiation far exceeds maternal mitochondrial DNA and allozyme differentiation in the fresh water mussel, Anodonta grandis grandis. Evolution 50:952-957.

Loosanoff, V. L. & H. C. Davis. 1963. Rearing of bivalve mollusks. Adv. Mar. Biol. 1:1-136.

Menzel, R. W. 1955. Some phases of the biology of Ostrea equestris Say and a comparison whit Crassostrea virginica (Gmelin). Publ. Ints. Mar. Sci. 4:73-153.

Millican, P. F. & M. M. Helm. 1994. Effects of nutrition on larvae production in the European flat oyster, Ostrea edulis. Aquaculture 123: 83-94.

Morriconi & J. Calvo. 1980. Fertilidad y periodicidad del desove de Ostrea puelchana. Rev. Invest. Des. Pesq. 2:57-62.

Orton, J. H. 1927. Observations and experiments on sex-change in the European oyster (Ostrea edulis). Part I. The change from female to male. J. Mar. Biol. Assoc. 14:967-1045.

Pascual, M. S. 1997. Carriage of dwarf males by female Puelche oysters: The role of chitons. J. Exp. Mar. Biol. Ecol. 212:173-185.

Pascual, M. S. 2000. Dwarf males in the Puelche oyster, Ostrea puelchana: differential mortality or selective settlement? J. Shellfish Res. 19:815-820.

Pascual, M. S. & A. H. Bocca. 1988. Cultivo experimental de la ostra puelcbe, Ostrea puelchana D' Orb, en el Golfo San Matias, Argentina. In: J. Verreth, M. Carrillo, S. Zanuy & E. A. Huisman, editors. Aquaculture research in Latin America. The Netherlands: Pudoc Wageningen. pp. 329-345

Pascual, M. S. & E. A. Zampatti. 1995. Chemically mediated adult-larval interaction triggers settlement in Ostrea puelchana: applications in hatchery production. Aquaculture 133:33-44.

Pascual, M. S., O. Iribarne, E. A. Zampatti & A. H. Bocca. 1989. Femalemale interaction in the breeding system of Ostrea puelchana. J. Exp. Mar. Biol. and Ecol. 132:209-219.

Pascual, M. S., A. G. Martin, E. A. Zampatti, D. Coatanea, J. Defossez & R. Robert. 1991. Testing Argentinian oyster, Ostrea puelchana, in several French oyster farming sites. International Council for the Exploration of the Sea. C.M. 1991/K:30.

Perez Camacho, A. 1987. La produccion de semilla de ostra en criadero. Cuadernos del Area de Ciencias Mainas. Seminario de Estudos Galegos 2:19-30.

Shimmin, L. C., B. H. J. Chang & W. H. Li. 1993. Male-driven evolution of DNA sequences. Nature 362:745-747.

Solis, I. 1967. Observaciones biologicas en ostras (Ostrea chilensis) de Pullinque. Biol. Pesq. 2:51-82.

Sumner, C. E. 1972. Oysters and Tasmania. Tas. Fish. Res. 6:1-15.

Toro, J. E. & O. R. Chaparro. 1990. Conocimiento biologico de Ostrea chilensis Philippi 1845. Impacto y perspectivas de la ostricultura en Chile. In: A. Hernandez, editor. Cultivo de Moluscos en America Latina, Memorias Segunda Reunion Grupo Trabajo Tecnico, Ancud, Chile. Noviembre 1989. pp. 231-264.

Walker, R. & A. J. Power. 2001. Growth and gametogenic cycle of the crested oyster, Ostrea equestris, (Say, 1834), in coastal Georgia. J. Shellfish. Res. 20:945-949.

Walne, P. R. 1963. Breeding of the Chilean oyster (Ostrea chilensis Philippi) in the laboratory. Nature 197:676.

Walne, P. R. 1964. Observations on the fertility of the oyster (Ostrea edulis). J. Mar. Biol. Assoc. UK. 44:293-310.

Wilson, J. H. & J. Simons. 1985. Gametogenesis and breeding of Ostrea edulis on the West Coast of Ireland. Aquaculture 46:307-321.

Winter, J. E., C. S. Gallardo, J. Araya, J. E. Toro & A. Gleisner. 1983. Estudios en la ostricultura Quempillen, un estuario del sur de Chile. Parte II. La influencia de las factores ambientales sobre el crecimiento y los periodos de reproduccion en Ostrea chilensis. Mems Asociacion Lationoamericana de Acuicultura 5:145-159.


Laboratorio y Criadero de Moluscos, Instituto de Biologia Marina y Pesquera Alte. Storni. Guemes 1030, 8520 San Antonio Oeste, Rio Negro, Argentina

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Author:Elvira, M.
Publication:Journal of Shellfish Research
Article Type:Abstract
Geographic Code:1USA
Date:Jan 1, 2005
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