Hidden diversity in the tide pool ciliate Strombidium occulatum as revealed by mutiple molecular markers

• Published in: Journal of Eukaryotic Microbiology
• Main Authors: SNOEYENBOS‐WEST, OONA L.O., PIROG, KATARZYNA A., GRIFFIN, AUTUMN, MCMANUS, GEORGE, COSTAS, BARBARA, KATZ, LAURA A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2005
• Subjects: North Atlantic
• Online Access: http://dx.doi.org/10.1111/j.1550-7408.2005.05202003_1_72.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1550-7408.2005.05202003_1_72.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1550-7408.2005.05202003_1_72.x

We find tremendous genetic diversity underlying the morphological entity Strombidium occulatum . We used multi‐locus sequence data to examine molecular diversity within S. occulatum across space and time so as to explore the biogeography and biodiversity of this marine ciliate species. We are sequenceing the internally transcribed spacer regions (ITS1 and ITS2) of the SSU rDNA gene, Mitochodrial SSU and Histone H4 from S. occulatum populations collected on either side of the North Atlantic Ocean: from tide pools along the western coast of the United Kingdom and the southern coast of New England. Samples were collected over short temporal (tidal) and both small and large spatial scales in order to explore the level of intraspecific genetic variation. Analyses of our sequence data show that a high level of DNA polymorphisms and genetic heterogeneity (e.g. up to 13% divergence at the ITS locus) underlies S. occulatum , indicating the existence of extensive cryptic speciation in this ciliate. We propose that the high levels of genetic diversity in S. occulatum arose during times of population subdivision (allopatry), perhaps driven by glacial retreat and sea‐level change during the Middle Miocene (∼15 mya) in Europe.