The first three pictures correspond to Actinoptychus senarius (Ehrenberg).

Ashfaque:

The form documented in upper three frames is correctly identified by Daniel as tidal Marsh species: Actinoptychus senarius (Ehrenberg) Ehrenberg, 1843. The form documented in lower three frames appears to be a broken Diatom - yet to be identified.

Best

Syed

I agree with the answer of Dr Daniel regarding the first three pictures, 4th picture is not clear but it is seems to be Cylotella. Last two pictures may be species of Navicula

Yes,Dr Geddada, that's probably a fragment of Navicula.

Dear All. Thanks for your reply. In the last three picture, the species is attached at the top, not broken one. It is the three pictures of the same specimens. However, I will check again.  Regards

The identification of the first three pictures by Daniel as Actinoptychus senarius (Ehrenberg) is agreeable. The identification of the  last three pictures need to be confirmed as commented by Dr.Jafar and Dr.Rao.SEM images are always recommended for diatom identification.

It is an Araphid diatom perhaps  a species Ulnaria or Synedra as I could make out from the picture.

Yes, the cells from the first three pictures are quite similar with Actinoptychus senarius. As for other images, I think that you need to study these cells under electron microscope  

Yes, the last three images are of an araphid diatom and it is most probably Lioloma.