Accumulation of "mushy jelly clumps" on the ground of a nutrient-poor, clear freshwater pool (about 20 cm in depth). These are probably colonies of <b><a href="https://en.wikipedia.org/wiki/Ciliate" class="extiw" title="en:Ciliate">ciliates</a></b>, possibly the taxon <i>Ophrydium</i> (cf. <i>versatile</i> or similar); Peritrichia; Ciliophora.
<a href="//commons.wikimedia.org/wiki/User:Fice" title="User:Fice">Christian Fischer</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>. <i><b>Location:</b></i> North-eastern Lower Saxony, Germany.