Title: Epizoic diatoms on Florida manatees Contact person: Bart Van de Vijver (bart.vandevijver@plantentuinmeise.be) Research group: Ecosystem Management (ECOBE), University Antwerpen & Research Department, Meise Botanic Garden Promotor: Prof Dr Bart Van de Vijver Co-promotor: Dr Thomas Frankovich (Florida international University, Miami, USA) Summary: Diatom (Bacillariophyta) genera and species have been described from the skin of cetaceans The dominant taxa comprising these communities are unique to the skin environment and have not been observed in the surrounding benthic environments or plankton Until recently, this unique group of diatoms was known as the “whale diatoms”, but recent discoveries of related, but new, obligate epizoic diatom species on turtles and manatees have expanded the epizoic host range of this unique flora Manatees harbor an especially unique epizoic diatom flora that is dominated by non-photosynthetic and therefore heterotrophic species Though these species have been described, little is known about overall diatom community structure on manatees and their spatio-temporal variability, or how these communities relate to individual manatees Diatoms are excellent bio-indicators and have been used in both applied environmental, biogeographical and paleo-ecological studies Epizoic diatom communities may inform on individual manatee health given the obligate and intimate relationship with their hosts and may also be indicative of surrounding aquatic environments Other than new species descriptions, manatee diatom communities have yet to be studied in detail The Florida manatee is a sub-species of the West Indian manatee and ranges from southern Florida in the USA and north along the coasts of the northwestern Atlantic Ocean and the eastern Gulf of Mexico, where their northward range is limited by cold winter temperatures Separate East and West Florida coast populations of Florida manatees are recognized Both populations migrate seasonally from marine coastal waters to warm-water refugia, which are often freshwater springs In 2015 and 2018, papers (Frankovich et al 2015, 2018) were published describing six new diatom species of the epizoic diatom genus Tursiocola from Florida manatees sampled throughout Florida during various years and seasons Though the described taxa were dominant in the skin flora, other co-occurring diatom taxa were not described, and analyses of diatom community structure were not performed In the present proposal, we would like to study the community structure of the epizoic diatom flora on Florida manatees, using the diatom collection of Frankovich et al The diatoms in the samples will be investigated using light and scanning electron microscopy Based on our limited knowledge of the diatom composition, it is likely that new species will be discovered The obtained data will be analysed using multivariate techniques to reveal patterns of diatom community structure and describe spatio-temporal variability of these communities Keywords: Epizoic algae – morphological research – microscopical algae Practical info: This proposal does not include field work Samples will be analyzed from existing collections A substantial part of the research will involve microscopical analysis Samples will be analyzed in the Algology lab at Meise Botanic Garden