Taxonomy and spatial distribution of coccolithophores in the southern Adria

Kokolitoforidi, fotosintetski jednostanični organizmi, jedna su od najvažnijih skupina morskog fitoplanktona. Od izuzetne su važnosti u kruženju elemenata u prirodi jer osim što obavljaju proces fotosinteze sudjeluju i u kruženju ugljika i sumpora u prirodi. Taksonomija kokolitoforida je izuzetno zahtjevna zbog malih dimenzija stanica, ultrastrukturnih obilježja vidljivih samo skenirajućim elektronskim mikroskopom te kompleksnog životnog ciklusa koji se sastoji od dvije morfološki različite faze. Provedeno je terensko istraživanje 2015. i 2016. godine na 15 postaja u južnom Jadranu, raspoređenih u tri transekta (P, M, V-transekt) te su sakupljena 183 uzorka. Skenirajućim elektronskim mikroskopom determinirane su 42 vrste kokolitoforida te je napravljena detaljna taksonomska lista. Dominantna vrste bile su Emiliania huxleyi, Syracosphaera sp. i Syracosphaera molischii. Karakteristične vrste za ovo područje su Syracosphaera pulchra, Syracosphaera ossa i Calcidiscus leptoporus. Uočena je i različita raspodjela fitoplanktona, ali i kokolitoforida i to ne samo između dva terena, nego i na području istih postaja u razmaku od nekoliko dana. Ova činjenica potvrđuje da je južni Jadran izuzetno hidrografski dinamično područje. Dinamičnost južnog Jadrana utječe na fitoplankton, kokolitoforide i primarnu produkciju, čime neizravno utječe i na više trofičke razine.Coccolithophores, photosynthetic unicellular organisms, are one of the most important groups of marine phytoplankton. Not only that they photosynthesize, they also play a big role in the carbon and sulfur cycle in nature. Taxonomy of coccolithophores is extremely challenging due to the small size of cells, ultrastructural features visible only by scanning electron microscope and a complex life cycle that consists of two morphologically different phases. Field research in 2015 and 2016 at 15 stations was conductet in the southern Adriatic, it was arranged in three transects (P, M, V-transect) and we have collected 183 samples. 42 different species of coccolithophores were determined with scanning electron microscope and detailed taxonomic list was created. The dominant species were Emiliania huxley, Syracosphaera sp. and Syracosphaera molischii. The characteristic species of this area are Syracosphaera pulchra, Syracosphaera ossa and Calcidiscus leptoporus. There was a visible difference in distribution of phytoplankton and coccolithophores not only between the two field researchs, but also in the field of the same station but in the space of a few days. This fact confirms that the southern Adriatic is a very hydrographic dynamic area. The dynamism of the southern Adriatic affects phytoplankton, Coccolithophorids and primary production, which indirectly affects the higher trophic levels