Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva, 84105, Israel.
University of Alaska Southeast, 11066 Auke Lake Way Hwy, Juneau, AK, 99801, USA.
Sci Rep. 2020 Jan 28;10(1):1287. doi: 10.1038/s41598-020-58262-6.
The Northern spot shrimp, Pandalus platyceros, a protandric hermaphrodite of commercial importance in North America, is the primary target species for shrimp fisheries within Southeast Alaska. Fishery data obtained from the Alaska Department of Fish and Game indicate that spot shrimp populations have been declining significantly over the past 25 years. We collected spot shrimps in Southeast Alaska and measured reproductive-related morphological, gonadal and molecular changes during the entire life history. The appendix masculina, a major sexual morphological indicator, is indicative of the reproductive phase of the animal, lengthening during maturation from juvenile to the male phase and then gradually shortening throughout the transitional stages until its complete disappearance upon transformation to a female. This morphological change occurs in parallel with the degeneration of testicular tissue in the ovotestis and enhanced ovarian vitellogenesis. Moreover, we obtained the entire mRNA sequence of the yolk protein precursor, vitellogenin, and monitored its transcript levels throughout the entire shrimp life-cycle. Vitellogenin transcript levels in the hepatopancreas increased in the early transitional stage until reaching a peak prior to extruding eggs. Such transcriptomic analyses, coupled with a comprehensive description of the gonad, external sex characters and timing of the reproductive life history of spot shrimps contribute to a better understanding of the hermaphroditic reproduction process in the cold Southeast Alaskan waters. This knowledge can contribute to a revision of current conservation efforts to maintain wild populations sustainable for both commercial and ecological considerations.
北方斑点虾（Pandalus platyceros）是一种具有商业重要性的雌雄同体鱼类，主要分布于北美洲，是东南阿拉斯加虾渔业的主要目标物种。阿拉斯加渔业和游戏部获得的渔业数据表明，过去 25 年来，斑点虾的数量一直在显著减少。我们在东南阿拉斯加收集了斑点虾，并在整个生命周期中测量了与生殖相关的形态、性腺和分子变化。附肢雄性（appendix masculina）是主要的生殖形态指标，它表明动物的生殖阶段，从幼体到雄性阶段，随着成熟而逐渐延长，然后在过渡阶段逐渐缩短，直到完全转化为雌性时完全消失。这种形态变化与卵黄蛋白原（vitellogenin）在卵巢中的退化和卵巢卵黄生成的增强同时发生。此外，我们获得了卵黄蛋白前体（vitellogenin）的整个 mRNA 序列，并在整个虾生命周期中监测其转录水平。在早期过渡阶段，肝胰腺中的卵黄蛋白原转录水平增加，直到在产卵前达到峰值。这种转录组分析，加上对性腺、外部性特征和斑点虾生殖生命周期的时间的全面描述，有助于更好地了解冷东南阿拉斯加水域的雌雄同体生殖过程。这些知识可以为当前的保护工作提供参考，以维持野生种群的可持续性，兼顾商业和生态考虑。
