Tamara Heartsill Scalley

One of my favorite experiences was sampling for aquatic fauna in the headwater streams at the highest elevations of the Luquillo Experimental Forest. The Elfin Cloud Forests have many small streams. Every surface is dripping wet, covered in all kinds of bryophytes, and the air is cool and humid. These tiny streams have small pools where the modified minnow traps that we used for sampling barely fit. The streams were full of life—with very high densities of filter feeder shrimp such as Atya lanipes.
These streams were the headwaters where streams first emerge from the ground at the highest elevation possible in the forest.It was a pleasant surprise, because we did not expect many shrimp to be in those pools at the top of the mountain where the river system begins. These shrimp are diadromous. Diadromous means that they came up the mountain by swimming upstream from the coast, where they were in the ocean saltwater. The shrimp swim and crawl to the highest elevation possible in this mountain stream system.