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Protistology ■ 17
and with silver impregnation methods. Cellular specific characteristics were analyzed and B. brasi-liensis was recorded in 23% of the samples with temperature values between 18 to 22 °C, and pH values from 3 to 6, demonstrating a wider range of temperature and pH tolerance, and a broad geographic distribution but only in Neotropical tank bromeliads. This is the first record for the species in these microecosystems at different altitudes in Mexico. Financial support was provided by National Council of Science and Technology (CONACYT) fellowship number 224627. Biol. Margarita Reyes and M.A. Aldi de Oyarzabal from Facultad de Ciencias, UNAM, are thanked for technical assistance and scientific illustration respectively.
PROTIST DIVERSITY AND INTERACTIONS WITHIN DEEP-OCEAN SEDIMENT AND WATER-COLUMN MICROBIAL COMMUNITIES
Edgcomb V.P.1, Pachiadaki M.12, Taylor C.1, Kormas K.Ar.3, Bernhard J.M.1, Taylor G.T.4
1 - Woods Hole Oceanographic Institution, Woods Hole, MA, USA
2 - Bigelow Laboratories, East Boothbay, Maine, USA
3 - University of Thessaly, Greece
4 - Stony BrookUniversity, Stony Brook, New York, USA [email protected]
Protists are integral members ofmarine food webs and exhibit complex relationships with other microbial taxa. Phagotrophic protists contribute significantly to carbon turnover in the sunlit ocean and evidence suggests grazing in the dark ocean can be significant as well. The molecular signatures of parasitic protists comprise significant fractions of many high-throughput sequencing datasets, suggesting a potentially important role in controlling populations oftheir host(s). Prokaryotic symbionts offree-living protists can be numerous, and, particularly in low-oxygen to anoxic marine habitats their collective metabolisms may contribute significantly to bio-geochemical cycling. Particular groups of protists are abundant and common inhabitants of marine sediment and water column oxyclines and very deep halocline habitats where physical associations with prokaryotes are frequently observed. Using open ocean oxygen minimum zones, deep hypersaline anoxic basins of East Mediterranean Sea, and the permanently stratified water column of Cariaco Basin, Venezuela as natural laboratories to link biogeochemistry and diversity, we report evidence of niche partitioning and specialized communities. Sediment communities seem to be dominated by different key players but exhibit similar niche
partitioning. Projects supported by NSF OCE-0849578, OCE-1061391, and OCE-1336082.
THE MARINE CARAVAN INVADING THE TWO BIG SEAS OF THE RED SEA AND THE MEDITERRANEAN THROUGH THE MARITIME SUEZ CANAL: I- CILIOPROTISTS Elserehy Hamed12, Al Quraishi Saleh1, Al-Farraj Saleh1
1 - Department of Zoology, College of Science, King Saud Uuniversity, Riyadh 11451, Saudi Arabia
2 - Department ofMarine Science, Faculty ofScience, Port Said University, Egypt [email protected]
Suez Canal is the main connecting link between the Red Sea in the south and Mediterranean in the north. It crosses many lakes, which in its turn represent different habitats. 28 plankton ciliate taxa and species were collected from the canal waters during the present study. Much interest was focused on determining from which end of the canal these organisms were invading the opposite sea. Planktonic ciliates appear to enter the Suez Canal from the south via water currents; to do so it needs to be carried over a distance of 25 km along the canal from the Gulf of Suez into the Bitter Lakes, then pass across the Bitter Lakes before being carried a further 15 km along the canal into Lake Timsah. Plankton ciliate affinities and differences between the eastern Mediterranean and the Red Sea were discussed in the light of the results of distribution studies of the twenty eight species of plankton carried out. These observations point to the role of the canal as a selective barrier and/or as a link in the process of marine bio-invasions of planktonic organisms, while cases of invasion from one sea to the other are more likely to occur in either direction, those concerning species of indo-Pacific origin are more successful and numerous (23species). Meanwhile, the Suez Canal acts as a local endemic habitat by itself (5 species). Thus, the opening of the Suez Canal during the year of 1869 caused marine bio-invasions in the Mediterranean Sea and rarely in the Red Sea. Accordingly Red Sea species invaded the Mediterranean ecosystem and not vice versa. Finally, it would be concluded that, a continuous monitoring programme must be launched especially after the new expansion of the canal and opening the new one to record the recent invasive plankton species and follow up the distribution and abundance of those previously recorded as invasive or alien species to assess their impacts on the native biodiversity ofthe Suez Canal, Red Sea and Mediterranean.
