Relevant scales of variability of the benthic allochthonous microalga Chrysophaeum taylorii

A Pilot Study on the Effects of Temperature on the Blooms of the Benthic Mucilage-Forming Microalga Chrysophaeum taylorii

“…This hypothesis is strongly supported by the data collected in the present study, highlighting the importance of temperature in C. taylorii abundance, as already proved for other similar species [5,6] and recently also suggested by Caronni et al [18] for the above-mentioned microalga. C. taylorii cells reached the maximum density on the substratum near the powerhouse (S 1 ), where the sea water temperature was close to 30 °C, and gradually decreased distancing from it along the considered temperature gradient.…”

“…Samples were collected scraping hard substratum at 1.5 m of depth where the microalga reaches its maximum abundance [18] by means of a brush sampler. A new sampling device (a cylindrical plexiglas tube with two screw threads at both ends and a stainless steel plunger with an exchangeable strip brush) which was recently proposed for sampling epilithic microalgae in lakes and streams [21] was also already used to obtain precise estimates of C. taylorii density [18].…”

“…A new sampling device (a cylindrical plexiglas tube with two screw threads at both ends and a stainless steel plunger with an exchangeable strip brush) which was recently proposed for sampling epilithic microalgae in lakes and streams [21] was also already used to obtain precise estimates of C. taylorii density [18]. All the collected samples were fixed with a Lugol's solution [22] and analyzed in the laboratory in the following months to characterize the microphytobethic community of each site and to estimate the cell abundance of C. taylorii.…”

“…Mucilage-Forming Microalga Chrysophaeum taylorii 10 seems to be already established steadily along the Sardinian [16][17][18], the Latium [19] and the Turkish [20] coasts. Its cells, despite their microscopic size (< 100 μm), are able to exude large amounts of mucilaginous material that becomes visible to the naked eye when their density reaches quite high values (~ 1,000 cells·mL -1 ) [16].…”

“…Due to the threat of range expansion and invasion of new areas, ecological studies on C. taylorii are most urgently needed, especially to better understand its bloom dynamics and to identify the environmental factors influencing its abundance. On this matter, Caronni et al [18] explained the summer temporal variability observed in C. taylorii cell density during a multiannual study on the species, hypothesizing the existence of a relationship with sea water temperature. However, no specific experimental evidence about it has been provided till today.…”