Benjamin Lee

All Publications

• Stentor stipatus is a new unicellular species that demonstrates habituation and unique phototaxis. Scientific reports Rajan, D. H., Lee, B., Albright, A., Tang, E., Ressler, K., Maravillas, A., Vargas, C., Marshall, W. F., Cortes, D. B. 2026; 16 (1)

  Abstract

  Stentor, the genus of large trumpet-shaped ciliates, is well-known for its complex morphology and striking behaviors. Members of this genus are distributed throughout the world in a wide and diverse pool of freshwater ecosystems. Recently, the molecular phylogeny of Stentor has been explored through comparison of 18 S small subunit (SSU) ribosomal DNA (rDNA) sequences, clarifying several previously mischaracterized species and species complexes. However, despite their wide distribution, to-date, only about a dozen species of Stentor have been described and verified by phylogenetic means. Here, we introduce the discovery of a new species within genus Stentor: Stentor stipatus spec. nov., so named for their distinctive cytosolic dark pigmented granules which surround the macronucleus and are also present cortically alongside cortically-distributed green microalgae. We present morphological, phylogenetic, ecological, and behavioral characterizations of these cells. Phylogenetic analysis of S. stipatus spec. nov. by comparison of SSU rDNA sequence suggests it is a distinct species from its closest relative, S. amethystinus. We demonstrate that S. stipatus spec. nov. is capable of habituation in response to repeated mechanical stimulation. Further, S. stipatus spec. nov. exhibits strongly directed positive phototaxis, like its relative S. pyriformis, but with a distinct action spectrum from both S. coeruleus and S. pyriformis. Finally, S. stipatus phototaxis response strength varies in a consistent pattern throughout the day, providing evidence of potential circadian regulation. This work expands the current understanding of the ecological distribution of and behavioral features present within genus Stentor.The online version contains supplementary material available at 10.1038/s41598-026-40277-0.

  View details for DOI 10.1038/s41598-026-40277-0

  View details for PubMedID 41720861

  View details for PubMedCentralID PMC13022238

• Phylogeny, morphology, and behavior of the new ciliate species Stentor stipatus. bioRxiv : the preprint server for biology Rajan, D., Lee, B., Albright, A., Tang, E., Maravillas, A., Vargas, C., Marshall, W. F., Cortes, D. 2024

  Abstract

  The study of evolution at the cellular level traditionally has focused on the evolution of metabolic pathways, endomembrane systems, and genomes, but there has been increasing interest in evolution of more complex cellular structures and behaviors, particularly in the eukaryotes. Ciliates have major advantages for such studies due to their easily visible surface patterning and their dramatic and complex behaviors that can be easily analyzed. Among the ciliates, the genus Stentor epitomizes the features that are useful for studying evolution: they are widespread in freshwater environments, easy to visualize because of their large size, and capable of complex behaviors such as learning, decision-making, and phototaxis. Here, we introduce the discovery of a new species within this genus: Stentor stipatus, so named for their distinctive dark brown aggregates. We present morphological, phylogenetic, ecological, and behavioral characterizations of these cells. The S. stipatus clade has a bootstrap value of 93 and is phylogenetically distinct from S. amethystinus, the closest related species which shares a sequence similarity of 98.9%. S. stipatus is capable of phototaxis and can also habituate more quickly than S. coeruleus, the Stentor species in which most habituation studies have previously been conducted. These findings expand our understanding of Stentor species diversity, natural history, and demonstrate common principles of complex behavior that are present in single-celled organisms.

  View details for DOI 10.1101/2024.08.03.606273

  View details for PubMedID 39131352

  View details for PubMedCentralID PMC11312564