A pink to red‐pigmented cryptophyte of undetermined taxonomic affinity was isolated and cloned from two seasonally ice‐covered. meromictic, saline Antarctic aquatic environments: Bayly Bay (BB) and Ace Lake (AL). The clones shared a number of morphological and ultrastructural similarities with other cryptomonad genera, which confounded identification by light and electron microscopy. Cellular pigments extracted from the AL clone showed an absorption maximum corresponding to the biliprotein Cr‐phycoerythrin 545, thus narrowing its potential taxonomic affinities. Partial 18S SSU ribosomal gene sequences were isolated from both the AL and the BB cryptomonads’ nuclear rDNA, whereas PCR‐amplified and their molecular phylogenies inferred from the subject sequences. Our results, and the results of another study that used our prepublished sequence data, invariably resolved both clones as very close matches with the Antarctic cryptophyte, Geminigera cryophila. When combined, the morphological, chemical, and molecular evidence suggested that both of our cryptophyte clones were a cryptomorph of the G. cryophila campylomorph. Slight differences between the AL and BB nuclear tree reconstructions suggested divergent microevolution following long‐term isolation of the AL population from the surrounding marine ecosystem. This study provides further compelling evidence that certain Cryptophyceae engage in a life‐history strategy, which includes alternating morphologically distinct cell‐types (dimorphism); cell‐types which without molecular analyses could be mistaken as novel taxa.

中文翻译：

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南极隐生植物双子叶植物（Cryptophyceae）中的二态性。

分离出一种粉红色至红色色素的未分类生物亲和力的植物，并从两个季节性冰覆盖的植物中克隆。盐生，盐碱的南极水生环境：Bayly Bay（BB）和Ace Lake（AL）。这些克隆与其他隐单胞菌属在形态和超微结构上有许多相似之处，这混淆了通过光镜和电子显微镜进行鉴定。从AL克隆中提取的细胞色素显示出最大吸收，对应于胆蛋白Cr-藻红蛋白545，因此缩小了其潜在的分类学亲和力。从AL和BB cryptomonads的核rDNA中分离出部分18S SSU核糖体基因序列，而PCR扩增及其分子系统发育可从主题序列中推论出来。我们的结果以及使用我们预先发布的序列数据进行的另一项研究的结果，双子座低温菌。当结合在一起时，形态，化学和分子证据表明，我们的两个隐生植物克隆都是嗜冷菌弯曲菌的隐变体。AL和BB核树重建之间的细微差异表明，在将AL种群与周围海洋生态系统长期隔离之后，微进化有所不同。这项研究提供了进一步的令人信服的证据，表明某些隐藻科参与了一种生活史策略，其中包括形态学上互不相同的细胞类型（二态性）。没有分子分析的细胞类型可能会被误认为是新的分类单元。