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Study on heritability of growth in the juvenile sea urchin Strongylocentrotus nudus.

ABSTRACT The heritability of growth of juvenile Strongylocentrotus nudus was analyzed using quantitative genetic methods. Twenty-one half-sib groups and 60 to 63 full-sib groups of juveniles were obtained by artificial fertilization of three to five females by single males based on a nested design. The body weight (g) and test diameter (cm) of the young was measured 3 and 5 months after metamorphosis. Maternal component estimates are significantly greater than paternal component estimates for both weight and diameter at both ages. Greater maternal components suggest large non-additive genetic effects that could not be differentiated with the available data. Estimates of heritability in the narrow sense calculated from the additive genetic component using a paternal half-sib correlation analysis ranged from 0.2167-0.4565 for weight and 0.2059-0.4998 for diameter. The results indicate significant maternal effects. The strength of the nested design and the paternal half-sib correlation analysis used in this study make the estimate the most precise and unbiased reported to date.

KEY WORDS: sea urchin. Strongylocentrotus nudus, growth, heritability

INTRODUCTION

Sea urchins are one of the most important aquaculture species in the world. The gonads have long been used as a luxury food and as a food source by common people in many countries (Hobson & Chave 1990, Shimabukuro 1991, Hagen 1996). Because of over-fishing, interest in aquaculture of sea urchins has increased greatly (Hagen 1998, Lawrence et al. 2001). One of the most important species for aquaculture is Strongylocentrotus nudus (Hagen 1996, Agatsuma 1998). Current culture of S. nudus has used seeds obtained from wild individuals (Gao & Chang 1999, Liao & Qiu, 1999). Analysis of populations of S. nudus in Japanese waters shows considerable range in size of small individuals, presumably of single cohorts (Agatsuma 1997). This could result from inter action of genetic characteristics and the environment. Vadas et al. (2002) found evidence for intrinsic variability in field populations of Strongylocentrotus droebachiensis. It is important to document the degree of heritability of growth in sea urchins because of its implications for both fisheries and aquaculture.

Demonstration of heritability is best done with comparisons of half-sib groups because they are less likely to be affected by environmental influence (Gjedrem 1992). Sib analysis techniques have been used for several important aquaculture species (Mallet et al. 1986, Rawson & Hilbish 1990, Hadley et al. 1991, Crenshaw et al. 1991, Newkirk et al. 1977, Benzie et al. 1997). The purpose of this study is to estimate heritability of growth in terms of body weight and diameter of juvenile Strongylocentrotus nudus.

MATERIALS AND METHODS

Experimental Design

This study used a classic nested mating design developed by Comstock and Robinson (1952) to partition the phenotypic variation in juvenile growth into its genetic and non-genetic causes. In this experiment each of 21 male Strongylocentrotus nudus was mated to 3 to 5 females, therefore generating 63 full-sib families and 21 half-sib families. The effects of males and females nested within males on growth were separated using nested analysis of variance (ANOVA). Juveniles were weighed and their diameters measured at 3 and 5 months of age.

Genetic Analysis

The covariance among full- and half-sibs provides the basis for the separation of phenotypic variance into genetic and environmental components of variance. The covariance among full- and half-sibs are calculated from the observed components of variance obtained from a three-level nested, unbalanced ANOVA (Table 1) and the General Linear Models procedure of the statistical analysis system (SAS) (Freund et al. 1986).

The experiment was a three-level classic nested, unbalanced design. Therefore the number of offspring in dams and in sires and in dams within sires should revise ("revise" means adjust). The effective means were computed using the equations:

Effective mean number of offspring in dams within sires

[K.sub.1] = [N - [summation of]([n.sub.ij.sup.2]/[dn.sub.i])]/(D - S)

Effective mean number of offspring in dams:

[K.sub.2] = [[summation of]([n.sub.ij.sup.2]/[dn.sub.i]) - [summation of] ([n.sub.ij.sup.2]/N)]/(S - 1)

Effective mean number of offspring in sires:

[K.sub.3] = (N - [summation of][dn.sup.2.sub.i]/N)/(S - 1)

in which S = number of sires, D = number of dams, [n.sub.ij] = number of offspring of the i-th sire and j-th dam, [dn.sub.1] = number of offspring of i-th sire, N = sum of number of offspring of all sires or all dams.

The phenotypic variance ([V.sub.P]) was separated into the additive genetic variance ([V.sub.A]), non-additive genetic variance ([V.sub.N] and environmental variance ([V.sub.E]), and the environmental variance ([V.sub.E]) was separated into the common environmental variance ([V.sub.E]) and the specific environmental variance ([V.sub.ES) using the standard separation of variance components (Falconer 1989). The causal components of variance were estimated from the full- and half-sib covariance using the relationships in Table 2.

Heritabilities were computed using the relationships:

[h.sup.2] = [V.sub.A]/[[V.sub.A] + [V.sub.NA] + [V.sub.E]]

Thus heritabilites in the narrow sense of paternal half-sib and maternal half-sib and full-sib were computed using the respective relationships:

[h.sup.2.sub.HS(S)] = 4 x [[sigma].sup.2.sub.S]/([[sigma].sup.2.sub.s] [[sigma].sup.2.sub.D] + [[sigma].sup.2])

[h.sup.2.sub.HS(D)] = 4 x [[sigma].sup.2.sub.D]/([[sigma].sup.2.sub.s] [[sigma].sup.2.sub.D] + [[sigma].sup.2])

[h.sup.2.sub.FS(D/S)] = 2 x ([[sigma].sup.2.sub.S] + [[sigma].sup.2.sub.D]) /([[sigma].sup.2.sub.S] + [[sigma].sup.2.sub.D] + [[sigma].sup.2]

Test of significant of heritability:

t = [h.sup.2]/[[sigma].sub.h.sup.2]

Paternal half-sib:

[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII.]

Maternal half-sib:

[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII.]

Full-sib:

[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII.]

Experimental Animal

Collection and Maintenance

Parental Strongylocentrotus nudus were taken from a cultured population in Dalian Bay on the northern coast of the Yellow Sea on 10 September 2001. These individuals were held at 18-22[degrees]C under 500 x 1 illumination and fed Laminaria japonica ad libitum for 32 days before spawning on 12 October 2001.

Fertilization

Individuals were removed from the aquaria and allowed to drain for 30 minutes before 1 mL 0.5 M KCL was injected into the coelomic cavity via the peristomial membrane. They were placed on the tops of flasks filled with sea water and the eggs and sperm collected from each individual for 30-60 minutes.

The eggs of each female were fertilized with sperm from a single male. Approximately 15,000 eggs from each female were placed in 100-L containers. Sperm were diluted 1000-fold (Uehara et al. 1990) and a small amount of the diluted sperm was added to the eggs. Fertilization success was examined microscopically. The fertilized eggs were washed two to three times to remove excess sperm. The embryos were layered on the bottom of flasks and transferred into a 50-L container to develop at 17-21[degrees]C at a density of four to five individuals/mL. Normal plutei developed in 30-35 h. (Rahman et al. 2000, Rahman et al. 2001).

Rearing

The larvae were transferred to 100-L containers of filtered seawater at 16[degrees]C. Densities of larvae from the 2-arm to the 8-arm stage were maintained at one to two individuals/mL. The water was changed twice daily. The larvae were fed Chaetoceros gracilis, Light was maintained at <300 LX. A small amount of air was babbled into the water, After 3 months the juveniles from each fertilization group were placed separately into plastic cages suspended in a large pool. The juveniles were fed fresh Laminara japonica. The cages were changed every 2 months. The juveniles were weighed and their diameter measured at ages of 3 and 5 months.

RESULTS

Growth--Increase in Body-weight and Test Diameter

Mean and standard deviation of the increase in body weight and test diameter of offspring at 3 and 5 months of age are given in Table 3.

Analysis of Variance of Body Weight and Test Diameter of Offspring

Analysis of variance demonstrated great differences in body weight and diameter of juveniles from different females mated with the same male and between males at both 3 and 5 months of age (Table 4).

Effective mean number of offspring for sires and clams after 3 months was computed as follows: effective mean number of offspring in darns within sire is [K.sub.1] = 34.689, in dams is [K.sub.2] = 38.821, and in sires is [K.sub.3] = 107.719 Effective mean number of offspring for sires and dams after 5 months was computed as follows: [K.sub.1] = 33.505: [K.sub.2] = 36.831; [K.sub.3] = 109.268.

The causal components of variance were estimated from the full- and half-sib covariance using the relationships in Table 5.

Estimations of Heritability of Body Weight and Test Diameter of Offspring

Heritabilities in the narrow sense of paternal half-sib and maternal half-sib and full-sib of body weight and diameter of 3-month-old Strongylocentrotus nudus were calculated on the result of component of variance and test (t = [h.sub.2]/[[sigma].sub.h.sup.2) of significant of heritability respectively as Table 6.

All of the heritability in the narrow sense of sire half-sib and the heritability in the broad sense of dam full-sib of body weight, test diameter of S. intermedius were significantly different from zero (t-test, P < 0.01).

Estimated heritability was somewhat different among the sire heritability, dam heritability, and the pooled (combined) heritability for all three traits. The estimates of dam heritability were higher than that of sire heritability, and the pooled (combined) heritability was moderate.

DISCUSSION

Predicted heritabilities of larval growth have been reported for full-sib correlation analysis for Crassostrea virginiica (Lannan 1972, Haley et al, 1975, Newkirdk et al. 1977) and Penaeus vannamei (Carr et al. 1997) and half-sib correlation analysis for Mercenaria mercenaria (Rawson & Hilbish 1990), Macrobrachium rosenbergii (Malecha et al. 1984), Penaeus vannamei (Carr et al. 1997, Benzie et al. 1996), and Penaeus stylirostri (Benzie et al. 1996). Predicted heritabilities of shell traits in wild littorina saxatilis populations have been reported for full-sib correlation analysis and offspring mother regression (Carballo et al. 2001). Estimates of heritabilities in the narrow sense generally ranged from 0.2-0.7. Realized heritability for increase in rate of growth in northern quahog and Argopecten irradians concetricus (Crenshaw et al. 1996, Crenshaw et al. 1991) and realized heritability estimates for growth in the Chilean oyster Ostrea chilensis (Toro et al. 1995). In our study, the estimates of heritabilities in the narrow sense for body weight at 3-5 months of age ranged from 0.217-0.457, consistent with those reported for other species. However, estimates are based on full-sib families bias heritabilities upwards when dominance and maternal effects are present (Lester, 1988). Because of the nested design and a paternal half-sib correlation analysis used, the estimate reported here is more precise and unbiased. This is the first report of heritability in the narrow sense reported for sea urchins.

An animal model includes a random effect for the additive genetic effect of each individual; and incorporates a complete set of additive genetic relationships among all individuals; and allows an unbiased estimation of variance components, even for the data involving selection and non-random mating (Gall & Bakar 2002, Sorensen & Kennedy 1986, Su et al. 1997). In this investigation full-sib family was taken as a random effect in a simple random model to account for the covariance among full-sibs caused by common environmental, dam and non-additive genetic effects, and half-sib family was used to account for covariance among half sibs caused by common environmental, dam, sire, and non-additive genetic effects. The results from the analyses based on this model were expected to be unbiased estimates of genetic parameters for the base population.

The much larger heritabilities computed from the female additive genetic component indicate the female genetic component still contain common environmental effects, maternal effects or non-additive genetic variance in the body weight or diameter. Dam effects are omnipresent in the study. The fact that the juvenile phase may indicate that the quality of yolk reserves plays a role in early development. Dam effects may persist after the onset of exogenous feeding. Crandell and Gall (1993) reported that dam effects persist up to 2 years in rainbow trout and up to 18-month-old Arctic char (Nilsson 1994).

The estimated heritability indicates significant additive genetic variation for body weight and test size all over the sampling periods. Sire heritability for the different variables were lower than dam heritability in many cases. However, all heritabilities in the narrow sense of body weight, test diameter of S. intermedius were significantly different from zero (P < 0.01). The heritabilities in the narrow sense estimate obtained from this experiment indicate there is sufficient variation in the base population of sea urchins to respond to natural or artificial selection on juvenile growth weight. This justifies selection of juveniles based on growth characteristics for cultured brood stock.
TABLE 1.
Analysis of variance for components of phenotypic variation.

 Source of Degree of Sum of
 Variance Freedom (df) Squares (SS)

Dams F x M - 1 S[S.sub.M]
Sires F - 1 S[S.sub.F]
Dams/sires F x (M - 1) S[S.sub.M(F)]
Offspring (error) F x M x (n - 1) SS

Total N - 1 S[S.sub.T]

 Source of Mean Square Expected Mean
 Variance (MS) Square E (MS)

Dams
Sires M[S.sub.F] [[sigma].sup.2] +
 [k.sub.2] [[sigma].
 sup.2.sub.M] + [k.
 sub.3] + [[sigma].
 sup.2.sub.F]
Dams/sires M[S.sub.M(F)] [[sigma].sup.2] +
 [k.sub.1] [[sigma].
 sup.2.sub.F]
Offspring (error) MS [[sigma].sup.2]

Total

TABLE 2.
Relationships between the covariance of full and half-sibs and
causal components of phenotypic variance.

 Component of Covariance
 Variance Components

[[sigma].sup.2.sub.F] CO[V.sub.HS]
[[sigma].sup.2.sub.M] CO[V.sub.FS] - CO[V.sub.HS]
[[sigma].sup.2.sub.E] [V.sub.P] - CO[V.sub.FS]
[[sigma].sup.2.sub.T] = [V.sub.P]
 [[sigma].sup.2.sub.F] +
 [[sigma].sup.2.sub.M] +
 [[sigma].sup.2]
[[sigma].sup.2.sub.F] + CO[V.sub.FS]
 [[sigma].sup.2.sub.M]

 Component of Causal
 Variance Components

[[sigma].sup.2.sub.F] 1/4 [V.sub.A]
[[sigma].sup.2.sub.M] 1/4[V.sub.A] + 1/4[V.sub.NA] + [V.sub.EC]
[[sigma].sup.2.sub.E] 1/2 [V.sub.A] + 3/4[V.sub.D] + [V.sub.ES]
[[sigma].sup.2.sub.T] = [V.sub.A] + [V.sub.NA] + [V.sub.EC] +
 [[sigma].sup.2.sub.F] + [V.sub.ES]
 [[sigma].sup.2.sub.M] +
 [[sigma].sup.2]
[[sigma].sup.2.sub.F] + 1/2 [V.sub.A] + 1/4[V.sub.D] + [V.sub.EC]
 [[sigma].sup.2.sub.M]

 Component of Calculation of
 Variance Component of Variance

[[sigma].sup.2.sub.F] {M[S.sub.F]- [(M[S.sub.M(F)] - M[S.sub.E])
 /[k.sub.1] x [k.sub.2] - M[S.sub.E]}
 /[k.sub.3]
[[sigma].sup.2.sub.M] (M[S.sub.M(F)] - M[S.sub.E])/[k.sub.1]
[[sigma].sup.2.sub.E] M[S.sub.E]
[[sigma].sup.2.sub.T] =
 [[sigma].sup.2.sub.F] +
 [[sigma].sup.2.sub.M] +
 [[sigma].sup.2]
[[sigma].sup.2.sub.F] +
 [[sigma].sup.2.sub.M]

TABLE 3.
Body weight and test diameter of offspring at 3 and 5 months of age.

 Body Weight (g) Test Diameter (mm)

 Growth Standard Standard
 Phase Average Deviation Average Deviation

3 months 0.014484 0.0103 2.916 0.945
5 months 1.366 0.377 8.492 2.841

TABLE 4.
Analysis of variance for components of phenotypic variation
of Strongylocentrotus nudus at 3 and 5 months of age.

 Body Weight

 Source of Degrees of Mean
 Variance Freedom (df) Square (MS) F-Value

3 months
 Dam 62 4.08340 x 9.893 **
 [10.sup.-3]
 Sire 20 7.26634 x 17.605 **
 [10.sup.-3]
 Dams within 42 2.56772 x 6.221 **
 sires [10.sup.-3]
 Full-sibs 2210 4.12753 x
 within dams [10.sup.-4]
 Total 2272
5 months
 Dams 59 0.79976 7.580 **
 Sire 20 1.31728 12.485 **
 Dams within 39 0.53436 5.065 **
 sires
 Full-sibs 2045 0.10551
 within dams
 Total 2104

 Body Weight Test Diameter

 Source of Mean Expected Mean
 Variance Square (MS) F-Value Square E (MS)

3 months
 Dam 6.01406 6.737 **
 Sire 10.71717 12.006 ** [[sigma].sup.2] +
 [k.sub.2] [[sigma].
 sup.2.sub.M] +
 [k.sub.3][[sigma].
 sup.2.sub.M]
 Dams within 3.77449 4.228 ** [[sigma].sup.2] +
 sires [k.sub.1] [[sigma.
 sup.2.sub.M]
 Full-sibs 0.89266 [[sigma].sup.2]
 within dams
 Total
5 months
 Dams 69.16935 8.570 **
 Sire 108.2978 13.418 ** [[sigma].sup.2] +
 [k.sub.2] [[sigma].
 sup.2.sub.M] +
 [k.sub.3][[sigma].
 sup.2.sub.F]
 Dams within 49.10348 6.084 ** [[sigma].sup.2] +
 sires [k.sub.1] [[sigma.
 sup.2.sub.M]
 Full-sibs 8.07108 [[sigma].sup.2]
 within dams
 Total

** P < 0.01; S = sires; D = dams; [K.sub.1] is the weighed mean
offspring number of females, [K.sub.2] = is the weighed offspring
number of females within sire, [K.sub.3] is the weighed mean
offspring number of sires.

TABLE 5.
Relationships between the covariance of full and half-sibs and causal
components of phenotypic variance.

Component of Causal Covariance
Variance Components Components

[[sigma].sup.2.sub.F] 1/4 [V.sub.A] [Cov.sub.HS]
[[sigma].sup.2.sub.M] l/4[V.sub.A] + [Cov.sub.FS]
 1/4 [V.sub.NA] - [Cov.sub
 + [V.sup.EC] .HS]
[[sigma].sup.2] 1/2[V.sub.A] [V.sub.P] -
 + 3/4[V.sub.D] [Cov.sub.
 + [V.sub.EW] FS]
[[sigma].sup.2.sub.P] = [V.sub.A] + [V.sub.P]
 [[sigma].sup.2.sub.F] [V.sub.NA] +
 [[sigma].sup.2.sub.M] + [V.sub.EC]
 [[sigma].sup.2] + [V.sub.EW]
[[sigma].sup.2.sub.F] + 1/2[V.sub.A] CO[V.sub.FS]
 [[sigma].sup.2.sub.M] + 1/4[V.sub.D]
 + [V.sub.EC]

 Result of Component of Variance

 3 Month 5 Month

Component of Test Body Test
Variance Body Weight Diameter Weight Diameter

[[sigma].sup.2.sub.F] 4.13895 x 0.06027 0.00678 0.50447
 [10.sup.-5]
[[sigma].sup.2.sub.M] 6.16974 x 0.08308 0.01280 1.22465
 [10.sup.-5]
[[sigma].sup.2] 4.275 x 0.89264 0.10551 8.07108
 [10.sup.-4]
[[sigma].sup.2.sub.P] = 5.40587 x 1.03598 0.12509 9.80020
 [[sigma].sup.2.sub.F] [10.sup.-4]
 [[sigma].sup.2.sub.M]
 [[sigma].sup.2]
[[sigma].sup.2.sub.F] + 1.03087 x 0.14335 0.01958 1.72912
 [[sigma].sup.2.sub.M] [10.sup.-4]

TABLE 6.
Heritabilitics in narrow sense ([h.sup.2]) and standard
error ([[sigma].sub.h.sup.2]).

 3 Months of Age

 Body Weight Diameter

[h.sup.2.sub.S] ** 0.306 [+ or -] 0.055 ** 0.233 [+ or -] 0.046
[h.sup.2.sub.D] ** 0.457 [+ or -] 0.071 ** 0.321 [+ or -] 0.046
[h.sup.2.sub.FS] ** 0.381 [+ or -] 0.063 ** 0.277 [+ or -] 0.051

 5 Months of Age

 Body Weight Diameter

[h.sup.2.sub.S] ** 0.217 [+ or -] 0.042 ** 0.206 [+ or -] 0.041
[h.sup.2.sub.D] ** 0.409 [+ or -] 0.064 ** 0.500 [+ or -] 0.072
[h.sup.2.sub.FS] ** 0.313 [+ or -] 0.054 ** 0.353 [+ or -] 0.058

** Denotes very significance between [h.sub.2] with
zero (P < 0.01); [t.sub.0.01] [infinity] = 2.576.


ACKNOWLEDGMENTS

The authors thank J. Song, G. D. Wang, R. L. Xing, and S. G. Yan for their invaluable assistance in the laboratory production of the family lines. They also thank J. M. Lawrence for editing the paper.

LITERATURE CITED

Agatsuma. Y. 1998. Aquaculture of the sea urchin (Strongylocentrotus nudus) transplanted from coralline flats in Hokkaido. pp 1541-1547.

Agatsuma, Y., S. Nakao, S. Motoya, K. Tajima & T. Miyamoto. 1998. Relationship between year to year fluctuations in recruitment of juvenile sea urchins Strongylocentrotus nudus and seawater temperature off the Sea of Japan coast in southwestern Hokkaido. Fisheries Science 64: 1-5.

Benzie, J. A. H., M. Kenway & L. Trott. 1996. Estimates for the heritability of size in juvenile Penaeus monodon prawns from half-sib mating. Aquaculture 152:49-53.

Carballo, M., C. Garcia & E. Rolan-Alvarez. 2001. Heritability of shell traits in wild Littorina saxatilis populations: Results across a hybrid zone. J. Shellfish Res. 1:415-422.

Carr, W. H., K. T. Fjalestad, D. Godin, J. Swingle. J. N. Sweeny & T. Gjedrem. 1997. Genetic variation in weight and survival in a population of specific pathogen free shrimp, Penaeus vannamei. In: T. W. Flegel & I. H. MacRae, editors. Diseases in Asian aquaculture III. Manila, Philippines: Asian Fisheries Society, Fish Health Section. pp. 265-271.

Comstock, R. E. & H. F. Robinson. 1952. Estimation of average dominance of genes. In: J. W. Gowen, editor. Heterosis. Ames: Iowa State College Press.

Crandell, P. A. & G. A. E. Gall. 1993. The genetics of age and weight at sexual maturity based on individually tagged rainbow trout (Oncorhynchus mykiss). Aquaculture 117:95-105.

Crenshaw, J. W., Jr., P. B. Heffernan & R. L. Walker, 1991. Heritability of growth rate in the southern bay scallop, Argopecten irradians concentricus (Say, 1822). J. Shellfish Res. 10:55-63.

Crenshaw. J. W., Jr., P. B. Heffernan & R. L. Walker. 1996. Effect of grow out density on heritability of growth rate in the northern quahog, Mercenaria mercenaria (Linnaeus, 1758). J. Shellfish Res. 15:341-344.

Falconer. D. S. 1989. Introduction to Quantitative Genetics. 3rd ed. New York: Longman, 340 pp.

Freund, R. J., R. C. Little & P. C. Spector. 1986. SAS System for linear models. Cary: SAS Institute.

Gall, G. A. E. & Y. Bakar. 2002. Application of mixed-model techniques to fish breed improvement: analysis of breeding-value selection to increase 98-day body weight in tilapia. Aquaculture 212:93-113.

Gao, X. S. & Y. Q. Chang. 1999. Edible sea urchins and aquaculture in China. Agriculture Press of China.

Gjedrem, T. 1992. Breeding plans for rainbow trout. Aquaculture 100:73-83.

Hadley, L. E., G. F. Newkirk & D. W. Waugh. 1975. A report on the quantitative genetics of growth and survivorship of the American oyster, Crassostrea virginica under laboratory conditions. 10th European Symp. Mar. Biol., Universal Press, Wetteren, Belgium, pp. 221-228.

Hadley, N. H., R. T. Dillon, Jr. & J. Manzi. 1991. Realized heritability of growth rate in the hard clam Mercenaria Mercenaria. Aquaculture 109-119.

Hagen, N. T. 1996. Echinoculture: from fishery enhancement to closed-cycle cultivation. World Aquaculture 27(4):6-19.

Hagen, N. T. 1998. Effect of rood availability and body size on out-of season gonad yield in the green sea urchin, Strongylocentrotus droebachiensis. J. Shellfish Res. 17:1533-1539.

Hobson, E. & E. H. Chave. 1990. Hawaiian reef animals, revised ed. Honolulu: Univ. of Hawaii Press.

Lannan, J. E. 1972. Estimating heritability and predicting response to selection for the Pacific oyster Crassostrea gigas. Proc. Natl. Shellfish. Assoc. 62:62-66.

Lawrence, J. M., A. L. Lawrence. S. C. McBride, S. B. George, S. A. Watts & L. R. Plank. 2001. Developments in the use of prepared feeds in sea-urchin aquaculture. World Aquaculture 32:34-39.

Lester, L. J. 1988. Difference in lavel growth among families of Peneaus stylirostris Stimpson and P. vannamei Boone. Aquacult. Fish. Manage. 19:243-251.

Lian, C. Y. & T. K. Qiu. 1999. A preliminary study on the artificial retiring of the larvae and juveniles of the purple sea urchin. Journal of Fisheries of China 1987 11:277-283.

Malecha, S. R., S. Masuno & D. Onizuka. 1984. The feasibility of measuring the heritability of growth pattern variation in juvenile freshwater prawns Macrobrachium rosenbergii (De Man). Aquaculture 38:347-363.

Mallet, A. L., K. R. Freeman & L. M. Dickie. 1986. The genetics of production characters in the blue mussel Mytilus edulis. I. A preliminary analysis. Aquaculture 57:133-140.

Newkirk, G. F., L. E. Haley, D. L. Waugh & R. Doyle. 1977. Genetics of larvae and spat growth rat in the oyster Crassostrea virginica. Mar. Biol. 41:49-52.

Nilsson, J. 1994. Genetics of growth of juvenile Arctic char. Trans. Am. Fish. Soc. 123:430-434.

Rahman, M. A., T. Uehara & L. M. Aslan. 2000, Comparative viability and growth of hybrids between two sympatric species of sea urchins (Genus Echinometra) in Okinawa. Aquaculture 183:45-56.

Rahman, M. A., T. Uehara & J. S. Pearse. 2001. Hybrids of two closely related tropical sea urchins (Genre Echinometra): evidence against postzygotic isolating mechanisms. Biological Bulletin. Marine Biological Laboratory 200:97-106.

Rawson, P. D. & T. J. Hilbish. 1990. Heritability of juvenile growth for the hard clam Mercenaria Mercenaria. Mar. Biol. 105:429-436.

Shimabukuro, S. 1991. Tripneustes gratilla (sea urchin), In: S. Shokita, K. Kakazu. A Tomori & T. Toma, editors. Aquaculture in tropical areas iv. Japan: Midori Shobo Co. Ltd. 360 pp. (English edition prepared by Yamachi M)

Sorensen, D. A. & B. W. Kennedy. 1986. Analysis of selection experiments using mixed model methodology. J. Anim. Sci. 63:245-258.

Su, G. S., L. E. Liljedahl & G. A. E. Gall. 1997. Genetic and environmental variation of female reproductive traits in rainbow trout (Oncorhynchus mykiss). Aquaculture 154:113-122.

Toro, J. E., M. A. Sanhueza, J. E. Winter, P. Aguila, & A. M. Vergara. 1995. Selection response and heritability estimates for growth in the Chilean oyster Ostrea chilensis (Philippi, 1845). J. Shellfish Res. 14: 87-92.

Uehara, T., H. Asakura & Y. Arakaki, 1990. Fertilization blockage and hybridization among species of sea urchins. In: M. Hoshi & O. Yamashita, editors. Proceedings of the 5th international congress of invertebrate reproduction on advances in invertebrate reproduction. Amsterdam: Elesevier. pp. 305-310.

Vadas, R. L., B. D. Smith, B. Beal & T. Dowling, 2002. Sympatric growth morphs and size bimodality in the green sea urchin (Strongylocentrorus droebachiensis). Ecological Monographs 72:113-132.

LIU XIAOLIN, (1),(3) CHANG YAQING, (2) XIANG JIANHAI, (1) * DING JUN (2) AND CAO XUEBIN (2)

(1) Experimental Marine Biology Laboratory, Institute of Oceanology, CAS, Qingdao 266071, China, (2) Key Lab of Mariculture and Biotechnology of the Ministry of Agriculture, Dalian Fisheries University, Dalian 116023, China; (3) College of Animal Science and Technology, Northwest Sci-Tech University of Agriculture and Forestry, Yangling, Shaanxi 712100, China

This is contribution number G1999012009 of 973 from the Chinese National Fundamental research project and Chinese High Technology Plan (2002AA628170).

* Corresponding author. E-mail: jhxiang@ms.qdiao.ac.cn
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Author:Xuebin, Cao
Publication:Journal of Shellfish Research
Date:Aug 1, 2004
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