Morphological and molecular examination of the ciliate family Lagynusidae (Protista, Ciliophora, Prostomatea) with descriptions of two new genera and two new species from China

Abstract

Ciliates in the class Prostomatea play an important role in the global microbial loop due to their significant abundances and broad feeding strategies at the foundation of food webs. Despite their importance in ecosystems, the taxonomy and systematics of this group of ciliates has long been poorly understood, with this being especially true for members of the family Lagynusidae. Here we examine four lagynusids collected from sandy beaches in China, using silver-staining and 18S rRNA gene sequencing techniques. These investigations revealed two new genera and two new species and provided details for two little known forms: Penardella marina gen. nov., sp. nov., Apolagynus cucumis (as reported by Penard. Études sur les infusoires d’eau douce. Georg and Cie, Genève, 1922) gen. nov., comb. nov., Lagynus minutus sp. nov., and Lagynus elegans (Engelmann in Z Wiss Zool 11:347–393, 1862) Quennerstedt (Acta Univ Lund 4:1–48, 1867). Penardella gen. nov. can be morphologically distinguished by having more than three dikinetidal perioral kineties. Apolagynus gen. nov. differs from the closely related genus Lagynus in the absence of a conspicuous neck-like region. The ciliature of Apolagynus cucumis is revealed here for the first time, which demonstrates the classification of this species within Lagynusidae. Furthermore, Apolagynus binucleatus (Jiang et al., 2021) comb. nov. is established according to the new finding. The results of our phylogenetic analyses based on the 18S rRNA gene support the establishment of two new genera and indicate that Lagynusidae is monophyletic, which further strengthens its valid taxonomic status.

Molecular characterization and zoonotic potential of Entamoeba spp., Enterocytozoon bieneusi and Blastocystis from captive wild animals in northwest China

“…Subsequently, gene sequences were assembled using SeqMan ver. 7.1.0 [ 65 , 66 ], and then aligned by BioEdit ver. 7.0.9.0 [ 67 , 68 ] and BLAST ( https://blast.ncbi.nlm.nih.gov/Blast.cgi ) to verify accuracy.…”

A new contribution to the raptorial ciliate genus Lacrymaria (Protista: Ciliophora): a brief review and comprehensive descriptions of two new species from Changjiang Estuary

“…Lacrymaria sapropelica Kahl, 1927 andL. urnula Kahl, 1930 both have a furrow encircling the neck-like region, which indicates that they should belong to the family Lagynusidae (Jiang et al, 2023). Since their ciliary patterns have not been investigated, further investigation is needed to determine their exact affiliations, particularly through protargol staining and SSU rRNA gene sequencing.…”

“…However, for a long time, its closest related genus Phialina was considered as its synonym, which results in the affiliation of most Lacrymaria species needing to be re-considered. Several Lacrymaria species have already been transferred to Phialina, Lagynus, or Pelagolacrymaria in recent studies (Supplementary Table S1; Foissner, 1983Foissner, , 1987Song and Wilbert, 1989;Sola et al, 1990;Foissner et al, 1995Foissner et al, , 1999Foissner et al, , 2002Wang et al, 2019;Jiang et al, 2023). Since the descriptions of most Lacrymaria species are rough and superficial, the species delimitation is understudied.…”