Phylum: Cyanobacteria   Family: Microchaetaceae

Planktothrix isothrix (Skuja) Komárek & Komárková

Data lacking but probably not too uncommon in freshwater lakes and lochs

References: 
John, D.M., Whitton, B.A. & Brook, A.J. (2011) - The Freshwater Algal Flora of the British Isles