A ~200 bp peak corresponds to the miRNA library, a ~208 bp peak represents piRNA, and a ~185 -192 bp peak corresponds to other small RNAs and RNA fragments. Please note that this 185 - 192bp peak can be particularly prominent in biofluids total RNA samples.
Peaks at 178 bp are adapter-dimers, which can occur when using lower RNA input amounts. If there are prominent adapter-dimers or other unwanted peaks in the library traces, it is advisable to perform gel size selection.