This is not my first mystery and would not be the last. That’s why I love science!
On 8/21/12 I went to Whitman Camp to do a program with a group of kids. We went to Billing Lake and collected macroinvertebrates. Always looking for those elusive crustaceans, I kept all I could find. I recently went over my collection and rebelled a population of amphipods, Hyallela azteca . But with the amphipods I found a true shrimp. This small and young shrimp is not completely developed and is difficult to identify as not all the parts are there, but I believe that it is a Grass Shrimp, or Palaemonetes spp.
Lake Billings is a fresh body water, Far from any brakeage or saline environment. I took some chemistry readings that day. There was a Dissolved Oxygen of 7.5 ppm, at a temperature of 25.3 degrees centigrade, a pH of 7.6 and an alkalinity of 80 ppm. which is high for that area but by no means saline. So what was a grass shrimp doing there?
Hyallela azteca is found in fresh water. I also saw some snails, Pseudosaccinea colunella, and some Helisoma spp, all fresh water organisms. This site is at least 7 miles from any salt water.
Here are some pictures of this grass shrimp and also a map.
Coordinates for this collection were 41.50938 Latitude and -71. 87062 longitudes.