Gamete quality in triploid Pacific oyster (Crassostrea gigas)

• Published in: Aquaculture
• Main Authors: Suquet, Marc, Malo, Florent, Quéré, Claudie, Ledu, Christophe, Le Grand, Jacqueline, Benabdelmouna, Abdellah
• Other Authors: Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire de Génétique et Pathologie des Mollusques Marins (LGPMM), Unité Santé, Génétique et Microbiologie des Mollusques (SGMM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: ACL; Crassostrea gigas; Gamete; Reproduction; Triploidy; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Pacific oyster
• Online Access: https://hal.science/hal-01483240; https://doi.org/10.1016/j.aquaculture.2015.08.032

International audience Triploidy induction in shellfish aims to obtain faster growth and sterility of reared individuals. Triploid Pacific oysters are most often not totally sterile, but have greatly reduced reproductive capacities compared to those recorded in diploid individuals. The description of gamete output in triploid aquatic animals is most often confined to the assessment of fecundity in females. The present work aims at further describing gamete quality of triploid Pacific oysters and comparing it to values observed in diploid individuals. Diploid and triploid oysters (produced by mating tetraploid males × diploid females) were reared in standard conditions and then transferred to the wild to allow the offspring to attain reproductive maturity. At the end of gametogenesis, the reproductive characteristics of both groups were estimated.ăăAfter gonad sampling, gametes could be observed in 92.9% diploid oysters compared with 42.0% in triploids. A higher number of spermatozoa was produced in diploids (344 ± 106 × 109 spermatozoa) compared with triploids (5 ± 7 × 109 spermatozoa). Furthermore, the percentage of motile sperm and sperm swimming speed were higher in diploids compared with triploids. In contrast, a higher intracellular ATP content was found in triploids (99.1 ± 34.0 nmole 10− 9 sperm) than in diploids (63.6 ± 20.7 nmole 10− 9 sperm). A higher number of oocytes was collected from diploid oysters (19.1 ± 3.8 × 106 oocytes), than from triploid ones (0.1 ± 0.1 × 106 oocytes). The D-larval yield was 45% higher for crosses (female × male) triploid × diploid, than the control (diploid × diploid). Furthermore, the lowest D-larval yield was measured for triploid × triploid crosses.ăăConsidering the present data, a partial estimation of the reproductive potential of triploid Pacific oysters (triploid × triploid crosses) could be close to 0.06% of that of diploid individuals. However, this estimation is probably over-evaluated because it does not take into account the low sperm production of triploids ...