A scud. Scuds are somewhat tolerant of pollution and can be found in fairly healthy waterbodies Photo by Michael Manas: https://en.wikipedia.org/wiki/Gammarus#/media/File:Gammarus_roeselii.jpg
A scud, photo by Michael Manas
A scud. Scuds are somewhat tolerant of pollution and can be found in fairly healthy waterbodies Photo by Michael Manas: https://en.wikipedia.org/wiki/Gammarus#/media/File:Gammarus_roeselii.jpg
New York State Parks and Historic Sites Blog 
