Estimation of realized fecundity (F_real, number of viable oocytes produced) is an essential, yet seldom-achieved element in the understanding of marine animal production and population dynamics. We used the Neutral Red (NR) vital stain to determine oocyte viability in spawns and gonad strippings of four species of commercially-important bivalves: Cerastoderma edule (L), Crassostrea gigas Thunberg, Mytilus edulis L, and Tapes philippinarum (Adams and Reeve). The utility of Trypan Blue as a complementary mortal stain was also assessed, and found to be unnecessary. Normal, live oocytes stained with NR, and were either spherical (mature oocytes) or pedunculated (immature oocytes); atresic/abnormal oocytes also stained with NR, allowing their ready recognition due to their abnormal shapes and cytoplasmic retraction. Dead oocytes did not stain with NR. Across the species studied, a considerable and highly variable proportion of spawned or stripped oocytes was either dead or non-viable; quantitative counts were performed for Cerastoderma edule, the only species for which > 5 spawns occurred. The high level and variability (34–85%) of dead or non-viable oocytes is consistent with a reproductive Red Queen dilemma, in which greater oocyte numbers do not translate to commensurately greater real fecundities, and also with a Sweepstakes Reproductive Success strategy, in which a large range of F_real confronts the considerable variability of intertidal environmental conditions. Neutral Red vital staining is a promising tool for the elucidation and optimization of crucial yet previously intractable aspects of bivalve hatchery production, genetic improvement, restocking, stock management, and conservation.

估计已实现的繁殖力（F _real，生产的活卵母细胞数）是了解海洋动物生产和种群动态的必要但很少实现的要素。我们使用中性红（NR）活体染色来确定四种重要商业双壳类动物的卵和性腺剥皮中的卵母细胞生存力：角皮病（Lera），Crassostrea gigas Thunberg，可食用的Mytilus edulis L和Tapes philippinarum（亚当斯和里夫）。还评估了锥虫蓝作为补充性凡人染色剂的效用，发现它是不必要的。正常的活卵母细胞被NR染色，呈球形（成熟的卵母细胞）或带蒂的（未成熟的卵母细胞）。顽固性/异常卵母细胞也被NR染色，由于其异常的形状和细胞质收缩而易于识别。死亡的卵母细胞没有被NR染色。在所研究的物种中，相当大且高度可变的产卵或剥离卵母细胞死亡或不能存活。对皮肤角质病进行了定量计数，仅有的物种>产生了5个生成物。死亡或无法存活的卵母细胞的高水平和变异性（34-85％）与生殖红皇后困境有关，在卵中，卵母细胞数量的增加并不能转化为相应的实际繁殖力，也与抽奖生殖成功的策略有关，其中大范围的F _real面临潮间带环境条件的巨大变化。中性红生命线染色是阐明和优化双壳孵化场生产，遗传改良，放养，种群管理和保存等关键但以前难以处理的方面的有前途的工具。