Age-dependence of cultured pearl grade and colour in the black-lipped pearl oyster Pinctada margaritifera
|Author(s)||Ky Chin-Long1, Demmer Jonathan1, Blay Carole1, 2, Lo Cedrik3|
|Affiliation(s)||1 : IFREMER, UMR EIO241, Labex Corail, Ctr Pacific, BP 7004, F-98719 Taravao, Polynesie Franc, France.
2 : USR 3278 CRIOBE CNRS EPHE, CRIOBE, Moorea, French Polynesi, France.
3 : Direct Ressources Marines & Minieres, Papeete, Polynesie Franc, Fr Polynesia.
|Source||Aquaculture Research (1355-557X) (Wiley), 2017-03 , Vol. 48 , N. 3 , P. 955-968|
|WOS© Times Cited||6|
|Keyword(s)||pearl oyster age, Pinctada margaritifera, surgreffe, pearl grade, pearl colour|
|Abstract||Pinctada margaritifera is an economically important marine bivalve species for cultured pearl production in French Polynesian aquaculture. In order to evaluate the influence of donor oyster age on pearl quality traits, experiments were conducted over 6 years using both grafts and surgreffe operations. At harvest, 6 pearl quality traits were recorded and compared: surface defects, luster, grade, darkness level, and visual color. Analyzing the quality traits of pearls harvested in the initial graft process and those of pearls obtained from surgreffe experiments allowed a comparison of the influence of pearl sac cells originating from the initial mantle graft, which aged together with their recipient oysters. The results demonstrated a significant decrease between these successive grafts in luster, grade (A-B-C,) darkness level, and green color – traits that are of major importance in the pearl market. The duplicated graft experiment allowed the comparison of donor oyster families at 2 and 5 years old, where a mantle graft was inserted into recipient oysters aged 2.5 years old. The results showed the same tendencies to a lesser extent, with 1) an improved pearl grade, predominantly through a most important rate of 0 surface defect category, and 2) a green / grey ratio in favor of the younger donor. A comparison between the graft-surgreffe and the duplicated graft experiments also highlighted: 1) the indirect role played by the younger recipient oysters, which must be optimized for optimal pearl quality realization, and 2) the complex interplay between donor and recipient oysters.|