中国曲丝藻属新记录种——温泉曲丝藻(Achnanthidium thermalis)

Achnanthidium thermalis,a new recorded species of Achnanthidium from China

底栖硅藻是水体生态系统中的重要初级生产者,由于其对环境具有敏感性,可用做水体生态系统的指征生物,因此底栖硅藻生物多样性调查工作尤为重要。本研究于乌梁素海的底栖硅藻调查中发现了中国曲丝藻属新记录种—温泉曲丝藻(Achnanthidium thermalis Rabenhorst)。结合光学显微镜和电子显微镜进行观察,发现该种具备曲丝藻属基本特征,又因其具有中央区两侧线纹不对称,仅一侧线纹延伸至壳缘的特征,我们将其鉴定为温泉曲丝藻。进一步分析电子显微镜下该种特征,发现其具有典型的双列线纹,而曲丝藻属的常见种类线纹特征通常为单列线纹。依照分类依据,将其鉴定为温泉曲丝藻。

Benthic diatoms are important primary producers in aquatic ecosystems.Benthic diatoms can be used as indicators for aquatic ecosystems due to their environmental sensitivity.Therefore,the study of benthic diatom biodiversity is particularly important.Achnanthidium thermalis Rabenhorst,a new species of the genus Achnanthidium was recorded in the Wuliangsu Lake of China.Combining the light and scanning electron microscope characteristics,this study found this species had the essential characteristics of Achnanthidium.Meantime,asymmetric striae on both sides of the central area and only one side striae extend to the valve edge.Based on these characteristics,it was identified as A.thermalis.Further analysising of the characteristics from scanning electron microscope revealed typical diallel striae for this species.Commonly,single striae was found in other species of Achnanthidium.Thus,we considered that this species was quite unique.In this paper,according to the classification reference proposed by Round et al.in 1996,we named this species A.thermalis.This species was discovered in Wuliangsu Lake,and was reported in China for the first time.Our result expands the distribution region of this species and provides data for the research on the diversity of benthic diatoms in China.