Help needed identifying two specimens

[MikeBradley]

I found these two specimens in a sample from the reed beds in a local freshwater pond. One seems to have some similarities to a pair of diatoms , but unlike any I've seen before, the pair is 60um wide and 75 long, it was taken at 20x 0.46NA . The other image was taken at 40x 0.95 NA and was moving slowly but with no evidence of flagella or cilia, it was 190 x 130 um.. Any suggestions about their ID would be most welcome.
Thanks
Michael

[shawn perez]

I found these two specimens in a sample from the reed beds in a local freshwater pond. One seems to have some similarities to a pair of diatoms , but unlike any I've seen before, the pair is 60um wide and 75 long, it was taken at 20x 0.46NA . The other image was taken at 40x 0.95 NA and was moving slowly but with no evidence of flagella or cilia, it was 190 x 130 um.. Any suggestions about their ID would be most welcome.
Thanks
Michael

Hi mike, I've come across the oval shaped organism too while scanning moss samples on my lil water bear hunt.
Not sure what those are.. would really like to know

[75RR]

I found these two specimens in a sample from the reed beds in a local freshwater pond. One seems to have some similarities to a pair of diatoms , but unlike any I've seen before, the pair is 60um wide and 75 long, it was taken at 20x 0.46NA .

Not sure if you will find this comment helpful but my first reaction was crustacean body part,

did a little searching and came up with Aulacoseira sp. which at first sight looked potentially promising.

There are however two problems, firstly size, these are very small diatoms.

Secondly the cells are joined using the spines, think interlocking fingers, while your image has spines in each section facing the same way.

Much like a crustacean in fact.

[MikeBradley]

Thanks for the suggestion 75RR, I'm now thinking that that image may well be from a branchiopod body part or perhaps part of a larval casing. I'll keep looking!
I did take look at Aulacoseira sp. and that was a very interesting and informative diversion from my quest, thanks for the idea.

I haven't had any ideas about the second image so far and I've now found more examples of these in a sample so that investigation must continue.

Michael

[DonSchaeffer]

The mysterious part is that the specimen looks like it has children's drawings or aboriginal drawings scrawled on it.