title: Phenology of cryptomonads and the CRY1 lineage in a coastal brackish lagoon (Vistula Lagoon, Baltic Sea).
abstract: Cryptomonadales have acquired their plastids by secondary endosymbiosis. A novel clade-CRY1-has been discovered at the base of the Cryptomonadales tree, but it remains unknown whether it contains plastids. Cryptomonadales are also an important component of phytoplankton assemblages. However, they cannot be readily identified in fixed samples, and knowledge on dynamics and distribution of specific taxa is scarce. We investigated the phenology of the CRY1 lineage, three cryptomonadales clades and a species Proteomonas sulcata in a brackish lagoon of the Baltic Sea (salinity 0.3-3.9) using fluorescence in situ hybridization. A newly design probe revealed that specimens of the CRY1 lineage were aplastidic. This adds evidence against the chromalveolate hypothesis, and suggests that the evolution of cryptomonadales' plastids might have been shorter than is currently assumed. The CRY1 lineage was the most abundant cryptomonad clade in the lagoon. All of the studied cryptomonads peaked in spring at the most freshwater station, except for P. sulcata that peaked in summer and autumn. Salinity and concentration of dissolved inorganic nitrogen most significantly affected their distribution and dynamics. Our findings contribute to the ecology and evolution of cryptomonads, and may advance understanding of evolutionary relationships within the eukaryotic tree of life.
authors.affiliation: Institute of Microbiology Czech Academy of Sciences, Center Algatech, ul. Novohradska 237, 37981, Třeboň, Czech Republic.|Department of Fisheries Oceanography and Marine Ecology, National Marine Fisheries Research Institute, ul. Kołłątaja 1, 81-332, Gdynia, Poland.
authors.forename: Kasia
authors.initials: K
authors.lastname: Piwosz
authors.affiliation: Department of Fisheries Oceanography and Marine Ecology, National Marine Fisheries Research Institute, ul. Kołłątaja 1, 81-332, Gdynia, Poland.
authors.forename: Janina
authors.initials: J
authors.lastname: Kownacka
authors.affiliation: Department of Fisheries Oceanography and Marine Ecology, National Marine Fisheries Research Institute, ul. Kołłątaja 1, 81-332, Gdynia, Poland.
authors.forename: Anetta
authors.initials: A
authors.lastname: Ameryk
authors.affiliation: Department of Fisheries Oceanography and Marine Ecology, National Marine Fisheries Research Institute, ul. Kołłątaja 1, 81-332, Gdynia, Poland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Zalewski
authors.affiliation: Limnological Station, Institute of Plant Biology, University of Zurich, Seestr. 187, CH-8802, Kilchberg, Switzerland.
authors.forename: Jakob
authors.initials: J
authors.lastname: Pernthaler
mesh_terms: D044785:Cryptophyta / Q000166:cytology / Q000502:physiology*; D000071421:Life History Traits; D018087:Plastids / Q000502:physiology; D011044:Poland; D054712:Salinity
keywords: Baltic Sea; CRY1 lineage; Cryptophyceae; chromalveolate hypothesis; coastal waters; estuaries; eutrophic waters; evolution; nanophytoplankton; plastid origin