ABSTRACT

Many dinoflagellate groups have been overlooked because of their small size compared with their larger counterparts; consequently, little is known about their diversity, distribution, and contribution to the planktonic community. Ansanella is a recently described genus of small marine planktonic dinoflagellates belonging to the order Suessiales. In this study, morphological observations together with molecular SSU and LSU rDNA analyses of clonal strains from the Catalan coast (NW Mediterranean Sea) allowed the identification of A. cf. natalensis and a newly reported species, Ansanella catalana. The cells of A. catalana are oval and 9.6–15.5 μm long; the cell surface is covered with amphiesmal vesicles arranged in 10–13 latitudinal rows; the episome has an apical furrow complex with a single elongated apical vesicle; a type E eyespot is also present. This newly identified species can be distinguished from congeneric species by morphological details of the cell surface, the presence of mucocysts and an extrusome type not previously reported in dinoflagellates. The characterization of this structure could provide insights into extrusome evolution in dinoflagellates. Metabarcoding analysis of plankton and sediment samples from the Catalan coast revealed a wide distribution of Ansanella and the remarkable contribution of this genus to the dinoflagellate communities from three different coastal habitats.

Highlights

• Members of Ansanella genus are widespread along the Catalan coast.

• A new species of the genus Ansanella (Dinophyceae) is described.

• A new type of extrusome was observed.

摘要

许多甲藻类群由于与较大的同类相比体积小而被忽视。因此，人们对它们的多样性、分布和对浮游群落的贡献知之甚少。Ansanella是最近描述的属于 Suessiales 目的小型海洋浮游甲藻属。在这项研究中，形态学观察以及来自加泰罗尼亚海岸（西北地中海）的克隆菌株的分子 SSU 和 LSU rDNA 分析允许鉴定A . 参看。natalensis和一个新报道的物种，加泰罗尼亚 Ansanella。A. catalana的细胞椭圆形，长 9.6–15.5 μm；细胞表面被两性囊泡覆盖，排列成10-13个纬度行；附加体具有带有单个细长顶端囊泡的顶端沟复合体；E型眼斑也存在。这种新发现的物种可以通过细胞表面的形态学细节、粘液囊的存在和以前在甲藻中未报道过的挤出体类型与同类物种区分开来。这种结构的表征可以提供对甲藻中挤出体进化的见解。来自加泰罗尼亚海岸的浮游生物和沉积物样本的元条形码分析揭示了Ansanella的广泛分布以及该属对来自三个不同沿海生境的甲藻群落的显着贡献。

强调

• Ansanella属的成员分布在加泰罗尼亚海岸。

• 描述了Ansanella (Dinophyceae)属的一个新种。

• 观察到一种新型的挤出体。