CC BY
82
20 • "PROTIST—2016
detail the ultrastructure of Vitrella brassicaformis, concentrating on the apical region of the flagellar stage. A previous work described a lifestage, surrounded by roughly structured matter of the containing sporangium, with an intracytoplasmic axoneme structure suggested to develop into mature flagellum. Here we describe a novel stage with cells developing a flagellum extracellularly. These cells concurrently bud off the center of the sporangium, surrounded by smooth matter, in a process reminiscent of ectomerogony as seen in Eimeria. We suggest that the former process generates gamete-like flagellate progeny, while the latter process yields zooflagellates. We failed to find apical structure similar to the pseudoconoid in C. velia. We propose that the common ancestor of Apicomplexa and "chrompodellids" exhibited a complex lifecycle, while extant descendants underwent gradual reduction of these processes as forced by their environment. Acknowledgement: The authors would like to thank the Czech Science Foundation (JK, HJE, MO) and the Czech Academy of Sciences (ZF) for funding.
DIFFICULTIES IN ASSESSING THE GLOBAL DISTRIBUTION OF A MODEL ORGANISM - THE BIOGEOGRAPHY OF FAVELLA PANA-MENSIS (ALVEOLATA, CILIOPHORA) Ganser M., Agatha S.
University ofSalzburg, Dept. Ecology and Evolution maximilian.ganser@stud.sbg.ac.at Accurate circumscriptions and determinations of species are essential for biodiversity and biogeo-graphy assessments; traditionally, the morpho-species concept was employed. Tintinnid ciliates are exceptional as - in contrast to the vast majority of ciliates - the whole taxonomy and classification of the more than one thousand marine planktonic species are almost exclusively based on characteristics of their vase-shaped loricae (houses). Because it is relatively easy to collect, preserve, examine, and classify, the lorica has allowed the accumulation of invaluable diversity and distribution data for more than two centuries. However, lorica-based taxonomy is problematic because of the high intraspecific variability and interspecific similarity of the loricae; so, the species limitations are currently unknown. Besides misidentifications, the diversity and geographic ranges perceived are especially affected by revisionary taxonomic treatises differing in their species circumscriptions from the original descriptions due to synonymisation (range of morphologic features became wider) and splitting (range of features became smaller) of species. Despite these difficulties, Montagnes (2013)
suggested the tintinnid genus Favella as a model for planktonic ciliates. In the present study on the biogeography of Favella panamensis, the species records from about one hundred of taxonomical and ecological studies were classified according to their quality: (i) reliable records from the type and neo-type localities mentioned in the original description and authoritative redescription; (ii) more or less reliable records supported by descriptions, measurements, and/or illustrations that fit the original description and redescription; and (iii) unsubstantiated records (mostly simple species lists) based on uncertain identifications. The comparison of the data provided by substantiated records with the original description revealed false positive and negative identifications. Since currently the species circumscriptions are uncertain, the usage of the original descriptions or authoritative redescriptions for the identification of tintinnid ciliates is strongly recommended. Only later, when the cell features and barcodes of the morphotypes are known, we might be able to perform justified synonymisations. References. Montagnes (2013): Ecophysiology and behavior of tintinnids. In: Dolan J.R., Montagnes D.J.S., Agatha S., Coats W.D. & Stoecker D.K. (2013): The Biology and Ecology of Tintinnid Ciliates: Models for Marine Plankton. Wiley-Blackwell: 85-121.
THE BEGINNING: INFERENCE OF THE TINTINNID ANCESTOR'S MORPHOLOGY (ALVEOLATA, SPIROTRICHA, TINTINNINA) Ganser M., Agatha S.
University ofSalzburg, Dept. Ecology and Evolution maximilian.ganser@stud.sbg.ac.at Tintinnids are a speciose group of ciliates, whose taxonomy and systematics are almost exclusively based on lorica features. Physico-chemical factors and the cell cycle, however, influence these taxonomic characters, resulting in an artificial classification with several non-monophyletic groupings. The sparse cytological data and the more comprehensive molecular phylogenies indicate that the tintinnids developed in the marine environment and entered freshwater several times independently. The tintinnidiid genera Tintinnidium and Membranicola are typical representatives of the limnetic plankton and are characterized by a simple somatic ciliary pattern and a strong synapomorphy, namely, the two de-novo-originating ventral organelles. The family is sister to the remaining, mainly marine species. As yet, only a single member of the genus Tintinnidium, T. mucicola, is known to occur in marine and brackish coastal waters, suggesting that it might provide clues pivotal to
