Naslov
A new marine planktonic Entomoneis species from the Adriatic Sea

Autori
Mejdandžić, Maja ; Bosak, Sunčica ; Orlić, Sandi ; Ljubešić, Zrinka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
10th Central European Diatom Meeting Abstract and Program Book / Acs, Eva ; Buczko, Kristina - Budimpešta, 2016, 18-19

Skup
10th Central European Diatom Meeting

Mjesto i datum
Budimpešta, Mađarska, 20.04.2016. - 23.04.2016

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Diatoms ; Entomoneis

Sažetak
The genus Entomoneis Ehrenberg includes pennate diatoms with structurally complex frustules, characterized by bilobate raphe-bearing keel elevated from the valve body, the morphologically variable junction lines and numerous girdle bands. Entomoneis species are mostly epipelic, found in brackish or marine sediments, with few freshwater representatives. The systematics of the genus is still underexplored, as there are 45 recorded taxa of which only 18 are taxonomically accepted. Up to date, there are only three Entomoneis species recorded in the Adriatic Sea: Entomoneis alata (Ehrenberg) Ehrenberg, Entomoneis paludosa (W. Smith) Reimer and Entomoneis pulchra (Bailey) Reimer. Here we propose a new diatom species belonging to the genus Entomoneis isolated during BIOTA (Bio-tracing Adriatic water masses) expedition conducted in February/March 2015 in the southeastern Adriatic Sea. The enigmatic taxon was found in the water samples in low abundances (up to 200 cells/L), and three monoclonal strains were established from plankton net samples. The description and the proposed taxonomic affiliation are based on both morphological observations (LM, SEM, TEM) and molecular analyses from cultivated strains. In addition to characteristic Entomoneis features such as panduriform cells often torsioned along the apical axis and raphe with simple/straight endings positioned on the sigmoid keel, we found several peculiar morphological characters for the newly proposed species: (1) cells are very small, being 11-22 μm long and 3-7 μm wide, (2) frustules are very lightly silicified with very delicate appearance and without striae or fibulae visible in LM, (3) striae structure appears smooth in SEM, but TEM observations reveal two parallel rows of marginal rectangular perforations, (4) valvocopulae are perforated by teardrop shaped areolae and (5) junction lines are straight to slightly arcuate. According to our initial phylogenetic results, NJ tree based on rbcL gene sequence data places our isolates as a distinct subgroup in the Entomoneis clade negating close phylogenetic relation to any other recognized Entomoneis species. However, further analyses will give us the exact position of the adriatic species within the Entomoneis genus and a clearer picture of its relationship with other canal- raphe-bearing diatom genera.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA