Extended Observation Description on Melosira lineata
Melosira lineata (Roth) Guiry 2019
Morphological Details of Melosira lineata
The species is characterized by cylindrical to subspherical cell shape. The cell groups form filaments that are held together by mucilaginous pads. The cells characteristically associate in groups of two or three and are connected by mantle structures called “cingula”.
Fig. 1: Filament of Melosira lineata. Two groups of 3 cells each. Scale bar indicates 25 µm (right).
Sampling location: Baltic Sea, Kieler Förde, Kiel Fjord (Germany), Latitude: 54.3894126, Longitude: 10.1749055
Fig. 2: Upper left inset: The focal plane is at the chloroplasts, which line the frustule lying parietal (arrow). Groups of 2 cells each. Scale bar indicates 50 µm.
Main image: The cingula (double arrowhead) forming a cylindrical mantle connect two or three cells. These coats enclose the valves of the individual cells. The ornamentation of the cingula differs significantly from that of the valves (double headed arrow). Scale bar of main image indicates 25 µm.
The sexual reproduction of Melosira lineata
The sexual reproduction of centric diatoms (Centrales) is characterized by oogamy. In Melosira, the spermatozoids are formed in narrower, the oogonia in broader filaments. After meiosis, four mobile spermatozoa with one flagellum develop in the male gamete mother cells (antheridia), in each of the oogonia three meiotic nuclei collapse and only one egg cell capable of fertilization remains.
(After Krammer, K. and van den Hoek, C.)
Fig. 3: Spermatozoids: We can see flagella (arrow) and their golden-brown chloroplast (double arrowhead, color due to the accessory dye fucoxanthin) at the posterior end of each spermatozoid (arrowhead).
Scale bar indicates 50 µm.
© Wolfgang Bettighofer,
images under Creative Commons License V 3.0 (CC BY-NC-SA).
For permission to use of (high resolution) images please contact postmaster@protisten.de.
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New items
discoides
gibba
cassis
elongata
oblonga
bathystoma
capreolata
var. masurica
globulosa
truncata
parva
globularis
fimbriata
chinensis
wailesii
concinnus
filifera
lineare
urceolata
enchelys
oblonga
artocrea
crenulata
spec.
brevicolla
placentula
var. euglypta
bryophila
spiralis
galeata
mitrata
gibbosa
didelta
immanata
acuminata
granulata
mucosa
var. laevicincta
rectum
bacillifera
brevicaulis
nasutum
striolatum
teliferum
pseudopyramidatum