Berthella californica (W. H. Dall, 1900) is a widespread species of heterobranch sea slug distributed across the North Pacific Ocean, from Korea and Japan to the Galapagos Islands. Two distinct morphotypes are observed in B. californica, which differ in external coloration, egg-mass morphology and geographic distribution (with the exception of a small range overlap in Southern California). Molecular and morphological data obtained in this study reveals that these two morphotypes constitute distinct species. The name B. californica (type locality: San Pedro, California) is retained for the southern morphotype, whereas the name Berthella chacei (J. Q. Burch, 1944) (type locality: Crescent City, California) is resurrected for the northern morphotype. Moreover, molecular phylogenetic analyses recovered B. californica as sister to Berthellina, in a well-supported clade separate from Berthella, suggesting that the classification of B. californica may need additional revision.

中文翻译：

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加州贝氏菌 (Berthella californica) 物种复合体（异鳃亚纲：侧鳃亚科）系统学的综合方法


Berthella californica (WH Dall, 1900) 是一种广泛分布的异分支海蛞蝓，分布于北太平洋，从韩国、日本到加拉帕戈斯群岛。在B. californica中观察到两种不同的形态类型，它们在外部颜色、卵块形态和地理分布方面有所不同（南加州的小范围重叠除外）。本研究获得的分子和形态数据表明，这两种形态类型构成了不同的物种。南部形态型保留了B. californica （模式产地：加利福尼亚州圣佩德罗）这一名称，而北部形态型则重新命名为Berthella chacei （JQ Burch，1944）（模式产地：加利福尼亚州新月城）。此外，分子系统发育分析发现B. californica是Berthellina的姐妹，属于与Berthella分开的一个得到充分支持的分支，这表明B. californica的分类可能需要额外修订。