Digre Sander Vollmerhaus, Jorde Per Erik, Folkvord Arild, Hemmer-Hansen Jakob, Knutsen Halvor
Department of Biological Sciences, University of Bergen, Bergen, Norway.
Department of Biology, C. F. Møllers Allé 3, Aarhus University, Aarhus, Denmark.
J Fish Biol. 2025 Aug;107(2):628-638. doi: 10.1111/jfb.70070. Epub 2025 May 6.
Sexual size dimorphism (SSD) and skewed sex ratios are common in the animal kingdom, and marine fishes, such as the Atlantic cod (Gadus morhua), are no exception. This study utilized newly discovered sex-linked genetic markers to investigate young-of-the-year cod in the Skagerrak system, comprising approximately 2700 individuals from North Sea and fjord ecotypes. Overall, no significant difference in sex ratio was observed overall (51% females, 49% males), with consistent findings across 14 locations and three sheltering degrees. Although slightly more females were found in exposed areas, and slightly more males in sheltered regions, these differences were not significant. Size variation between female and male cod was generally negligible. These results indicate a likely purely genetic sex determination system in Atlantic cod and a lack of prematuration growth differences between sexes. This research enhances our understanding of the Atlantic cod, providing more insight into the Atlantic cod population in the Skagerrak and emphasizing the importance of genetic factors in sex determination.
两性体型差异（SSD）和偏态性别比在动物界很常见，海洋鱼类，如大西洋鳕鱼（Gadus morhua）也不例外。本研究利用新发现的性连锁遗传标记，对斯卡格拉克海峡系统中的当年生鳕鱼进行了调查，该系统包含约2700条来自北海和峡湾生态型的个体。总体而言，未观察到性别比的显著差异（51%为雌性，49%为雄性），在14个地点和三种庇护程度下均得到了一致的结果。尽管在暴露区域发现的雌性略多，在庇护区域发现的雄性略多，但这些差异并不显著。雌性和雄性鳕鱼之间的体型差异通常可以忽略不计。这些结果表明，大西洋鳕鱼可能存在纯粹的遗传性别决定系统，且两性之间不存在早熟生长差异。这项研究增进了我们对大西洋鳕鱼的了解，为斯卡格拉克海峡的大西洋鳕鱼种群提供了更多见解，并强调了遗传因素在性别决定中的重要性。
