New records of the colonial chrysophyte Urostipulosphaera articulata (Chrysophyceae, Ochromonadales) in China

By

An, Yalu
Hao, Junxue
Nan, Fangru
Lv, Junping
Liu, Qi
Liu, Xudong
Xie, Shu-Lian
Feng, Jia

Type

Article

Date of Publication

2025-6-12

Original Publication

Biodiversity data journal

Volume

13

Pages

1--16

Subjects

Chrysophyceae , Morphology , phylogenetic studies , taxonomy , Urostipulosphaera

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia Pensoft Publishers [2013]-

Identifiers

DOI: https://doi.org/10.3897/BDJ.13.e150900

 

Abstract

The genus Urostipulosphera was established in 2019. Its morphological characteristics are similar to Uroglena and Uroglenopsis, but it differs from both. This genus connects individual cells into communities through a dichotomous branching structure, which distinguishes it from Uroglena and Uroglenopsis. Although there are nine species in this genus, molecular data are available for only four species. Molecular data and species distribution records for Urostipulosphaera are severely lacking. Species of this genus have been recorded in a few locations in Europe and North America.<br> We identified three samples that were discovered in Shanxi Province, China, based on morphological characteristics and molecular phylogenetic analysis. Results of the polygenic phylogenetic tree, based on SSU, rbcL and ITS sequences, showed that the three samples were clustered with Urostipulosphaera articulata U5-5 from Czechia, with a high support rate of 100/1.00. Morphological observations further supported this result. Therefore, the three samples were identified as Urostipulosphaera articulata. This is the first report in China and enriches the geographic diversity of this species. Moreover, we found the long flagellum with mastigonemes under the scanning electron microscope complementing the description of the morphological characteristics of this species. The ITS2 secondary structure of the specimens differed from that of Urostipulosphaera articulata U5-5, which exhibited a loop and five-arm structure. A Bayesian relaxed clock analysis indicated that the genus Urostipulosphaera originated in the Early Cretaceous, approximately 109.85 million years ago (Ma) and diverged into two clades around 79.81 Ma.