Increasing parentage contribution in aquaculture broodstocks is important, in order to take full advantage of the available genetic makeup of the chosen fish, and to avoid inbreeding and loss of allele diversity over subsequent production generations. European sea bass (Dicentrarchus labrax) broodstocks were evaluated over two reproductive seasons to examine spawning kinetics, egg production, and parentage contribution during spontaneous/volitional spawning. In addition, we obtained preliminary results on the potential of a hormonal therapy to synchronize spawning and increase parentage contribution. Spawning lasted between 25 and 66 days in January-March and consisted of 12–21 daily spawns per broodstock, with individual females spawning 1–5 times and males participating in 1–8 spawns during each reproductive season. Daily fecundity was variable during the season, without any trend, and so were all the examined egg/larval quality parameters. Parentage assignment of the produced families indicated that the majority of progeny from a whole season may belong to a very small number of breeders, with four females producing up to 80 % of the analyzed eggs, while a single male may sire up to 57 % of the fertilized eggs. No significant improvement in the overall parentage contribution was obtained with the hormonal treatment, using gonadotropin releasing hormone agonist (GnRHa). Nevertheless, the daily fecundity was higher, and parentage of the eggs from the first spawn after GnRHa treatment was more equally distributed to multiple males/females, compared to any volitional spawns. The study demonstrates the need to further improve parentage contribution in European sea bass aquaculture, through synchronization of maturation and spawning. Although the GnRHa induction experiment was not replicated in the present preliminary study, the results suggest that hormonally-induced synchronization of maturation may have the potential of producing a larger number of progenies from more families, from where to select the next generation of breeders for a breeding program.

增加水产养殖亲本中亲本的贡献很重要，以便充分利用所选鱼类的可用基因组成，并避免近亲繁殖和在随后的生产世代中等位基因多样性的丧失。欧洲鲈鱼 ( Dicentrarchus labrax) 在两个繁殖季节对亲鱼进行评估，以检查自发/自愿产卵期间的产卵动力学、产蛋量和亲子关系。此外，我们还获得了关于激素疗法同步产卵和增加亲子关系贡献的潜力的初步结果。1-3 月产卵持续 25 至 66 天，每只亲鱼每天产卵 12-21 次，每个繁殖季节雌性个体产卵 1-5 次，雄性参与 1-8 次产卵。每天的繁殖力在季节中是可变的，没有任何趋势，所有检查的卵/幼虫质量参数也是如此。生产家庭的血统分配表明，整个季节的大多数后代可能属于极少数种鸡，四只雌性产生高达 80% 的分析卵子，而一个雄性可能产生高达 57% 的受精卵。使用促性腺激素释放激素激动剂 (GnRHa) 进行激素治疗后，总体亲子关系没有得到显着改善。然而，与任何自愿产卵相比，每日繁殖力更高，并且 GnRHa 处理后第一个产卵的卵的亲子关系更平均地分配给多个雄性/雌性。该研究表明需要通过同步成熟和产卵来进一步提高欧洲鲈鱼养殖中亲子关系的贡献。虽然在目前的初步研究中没有重复 GnRHa 诱导实验，