- Email: [email protected]
Inheritance of white coloration of the prismatic layer of shells in the Japanese pearl oyster, Pinctada fucata martensii, and its importance in the pearl culture industry
331
AESTRACTSOFPOSTERPAPERS
netically heterogeneous group in Norway, and show genetic variation between strains comparable to the variation among natural populations. Our results show that there is a good potential for producing genetically marked strains of Atlantic salmon for e.g. sea ranching, fish farming and research purposes.
Inheritance of white coloration of the prismatic layer of shells in the Japanese pearl oyster, Pinctada fucata martensii, and its importance in the pearl culture industry
K.T. WADA National
Research
Institute
of Aquaculture,
Nansei,
Mie 516-01
(Japan)
ABSTRACT Breeding experiments revealed that the white coloration of the prismatic layer of shells in the Japanese pearl oyster is inherited under the control of a recessive gene. Three matings were made; in two of them white female mated with white male and in the other white female with brown (most common type) male. The coloration of shells was observed in the 4-month-old spats of the progeny. The distribution of pigments in the prismatic and pearl layers of shells were also observed in both types of older specimens. All the offspring from the two matings with white parents had the white coloration of the prismatic layers, with a few exceptional brown types which might have been introduced accidentally from other matings. Meanwhile only brown type shells were obtained from the cross of whiter brown. These are expected ratios in crosses of brown heterozygous and white homozygous for a simple Mendelian character, although F, of these crosses have not been studied. Under the microscope, small amounts of dark pigments which relate partly to the shell marking in brown type were observed even in the prismatic layer of the white specimens. However, preliminary observation of the pearl layer showed that the amount of yellow pigments seemed smaller in white specimens than in brown ones. The former would be useful for the production of pearls without yellow pigments which are more valuable than others. This kind of albinism would also be useful for genetic experiments like chromosome manipulation.
Variation of allozymic polymorphism in Ostrea angasi and 0. edulis
F. BLANC and H. JAZIRI Laboratoire F-34032
de Zoogkographie
Montpellier
CPnPtique,
UniversitP
Montpellier
3, B.P. 5043,
CPdex J (France)
ABSTRACT Ostrea angasi, whose geographic
area is restricted
to the temperate
shores of South-Eastern
AESTRACTSOFPOSTERPAPERS
netically heterogeneous group in Norway, and show genetic variation between strains comparable to the variation among natural populations. Our results show that there is a good potential for producing genetically marked strains of Atlantic salmon for e.g. sea ranching, fish farming and research purposes.
Inheritance of white coloration of the prismatic layer of shells in the Japanese pearl oyster, Pinctada fucata martensii, and its importance in the pearl culture industry
K.T. WADA National
Research
Institute
of Aquaculture,
Nansei,
Mie 516-01
(Japan)
ABSTRACT Breeding experiments revealed that the white coloration of the prismatic layer of shells in the Japanese pearl oyster is inherited under the control of a recessive gene. Three matings were made; in two of them white female mated with white male and in the other white female with brown (most common type) male. The coloration of shells was observed in the 4-month-old spats of the progeny. The distribution of pigments in the prismatic and pearl layers of shells were also observed in both types of older specimens. All the offspring from the two matings with white parents had the white coloration of the prismatic layers, with a few exceptional brown types which might have been introduced accidentally from other matings. Meanwhile only brown type shells were obtained from the cross of whiter brown. These are expected ratios in crosses of brown heterozygous and white homozygous for a simple Mendelian character, although F, of these crosses have not been studied. Under the microscope, small amounts of dark pigments which relate partly to the shell marking in brown type were observed even in the prismatic layer of the white specimens. However, preliminary observation of the pearl layer showed that the amount of yellow pigments seemed smaller in white specimens than in brown ones. The former would be useful for the production of pearls without yellow pigments which are more valuable than others. This kind of albinism would also be useful for genetic experiments like chromosome manipulation.
Variation of allozymic polymorphism in Ostrea angasi and 0. edulis
F. BLANC and H. JAZIRI Laboratoire F-34032
de Zoogkographie
Montpellier
CPnPtique,
UniversitP
Montpellier
3, B.P. 5043,
CPdex J (France)
ABSTRACT Ostrea angasi, whose geographic
area is restricted
to the temperate
shores of South-Eastern