The on-site culture of live microalgae represents a major challenge for bivalve hatchery operations due to high cost and labour demands. This study evaluated the efficacy of commercially available microalgae concentrates as a partial or complete replacement diet for live microalgae for culture of the hard clam, Mercenaria mercenaria, larvae. Larvae were fed from D-larval stage to post-set, 2–14 days post fertilization (DPF). Larvae fed the complete replacement diets were significantly smaller than those fed partially replaced or live microalgae diets. Foot development was significantly delayed in larvae fed complete replacement diets compared to partially replaced or live microalgae diets. Although early survival (at 5 DPF) was similar among the treatments, final survival (at 14 DPF) varied significantly among treatments. The average final survival was 69%–77% for larvae fed live microalgae, 60%–61% for larvae fed partially replaced diets and 14%–16% for larvae fed complete replacement diets. These results suggest that a live microalgae diet could be partially replaced by a concentrate to feed hard clam larvae. However, complete replacement diet may be used only for a short duration (up to 3 days) without affecting survival.

中文翻译：

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评估微藻浓缩物作为硬蛤、Mercenaria mercenaria、幼虫的饲料

由于高成本和劳动力需求，活微藻的现场培养对双壳贝类孵化场的运营构成了重大挑战。本研究评估了市售微藻浓缩物作为活微藻的部分或完全替代饮食以培养硬蛤、Mercenaria mercenaria, 幼虫。幼虫从 D 幼虫阶段喂养到受精后 2-14 天 (DPF)。喂食完全替代饮食的幼虫明显小于喂食部分替代或活微藻饮食的幼虫。与部分替代或活微藻饮食相比，喂食完全替代饮食的幼虫足部发育显着延迟。尽管治疗中的早期存活率（5 DPF）相似，但最终存活率（14 DPF）在治疗之间存在显着差异。饲喂活微藻的幼虫平均最终存活率为 69%–77%，饲喂部分替代日粮的幼虫为 60%–61%，饲喂完全替代日粮的幼虫为 14%–16%。这些结果表明，活的微藻饮食可以部分地被浓缩物代替，以喂养硬蛤蜊幼虫。然而，