During recent decades, survey studies have documented the widespread presence of oocytes in the testes of male Smallmouth Bass Micropterus dolomieu collected from surface waters throughout the United States. There are few published reports of testicular oocytes (TO) in Smallmouth Bass before the 1990s, so it is difficult to know how long this has been occurring. Consequently, this study was conducted to evaluate the prevalence and severity of TO occurrence in whole fish specimens from two archival collections-the Smithsonian Institution's National Museum of Natural History in Suitland, Maryland, and Cornell University's Museum of Vertebrates in Ithaca, New York. Gonads were excised from 167 preserved male Smallmouth Bass that were originally collected between 1875 and 2004, and routine histologic sections were prepared and examined. The severity of TO was determined using a semiquantitative scoring system. Overall, 52.1% of male Smallmouth Bass were found to have TO. Affected fish had been collected in 11 of the 18 represented states, and TO were found in specimens harvested during decades as early as the 1880s and 1900s. Unfortunately, the small number of samples acquired at the earliest time periods precluded analyses of prevalence and severity trends over time. The results of this study demonstrated that the phenomenon of TO in male Smallmouth Bass is at least a century old and confirmed the widespread nature of this finding throughout the species' historic range. Further research efforts should focus on determining the baseline prevalence of TO in laboratory-reared male Smallmouth Bass that have not been exposed to endocrine active substances or the effects of experimental estrogen exposure on such fish.

中文翻译：

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来自两个档案馆藏品的小口黑鲈睾丸卵母细胞的组织病理学患病率和严重程度

近几十年来，调查研究记录了从美国地表水中收集的雄性小嘴鲈鱼的睾丸中广泛存在卵母细胞。在 1990 年代之前，关于小口黑鲈睾丸卵母细胞 (TO) 的报道很少，因此很难知道这种情况发生了多久。因此，本研究旨在评估来自两个档案馆藏的全鱼标本中 TO 发生的流行率和严重程度 - 史密森学会位于马里兰州苏伊特兰的国家自然历史博物馆和位于纽约伊萨卡的康奈尔大学脊椎动物博物馆。从最初于 1875 年至 2004 年间收集的 167 条保存的雄性小口黑鲈中切除性腺，并制备和检查常规组织切片。使用半定量评分系统确定 TO 的严重程度。总体而言，52.1% 的雄性小嘴黑鲈被发现患有 TO。在 18 个代表州中的 11 个州收集了受影响的鱼，早在 1880 年代和 1900 年代，就在数十年收获的标本中发现了 TO。不幸的是，在最早的时间段内获得的样本数量很少，因此无法分析随时间推移的流行率和严重程度趋势。这项研究的结果表明，雄性小嘴黑鲈中的 TO 现象至少已有一个世纪的历史，并证实了这一发现在整个物种历史范围内的广泛性。