A Guide to Freshwater Fish and Shrimp of the U.S Virgin Islands (Gut Life)

This species is 1 of 5 freshwater shrimp inhabiting tropical streams also known as "guts" in St. Thomas U.S Virgin Islands. This species is diadromous or migratory, spawning in brackish/salt water and leaving the marine environment as juveniles and migrating into freshwater bodies such as creeks, streams and rivers. This species of filter feeder prefers pools with slow trickling water. Species are able to filter feed in pools with low velocity waters. This species varies from a dark brown color to a gray translucent color depending on tannins in the water that occur naturally from leaves and other plant related debris that essentially stains the water. Species turn translucent or gray in clear water. This species is usually really good at camouflaging itself under leaves, twigs and mud in the guts. At times they can be observed clinging to pieces of wood that have entered the pools in the gut. less ↑

Atya innocuous is a rare species in the guts in St. Thomas, U.S Virgin Islands. I believe it is a bio-indicator of water quality. During my M.S research at the University of the Virgin Islands I did not collect very many of this species in surveys. It is 1 or 5 species of shrimp. Atya innocuous resembles Atya lanipes, which is also present in guts in St. Thomas. This species is brown and tan in color, sometimes appearing though it has blotches and sometimes appearing a solid brown color. less ↑

This this species is 1 of 5 freshwater shrimp living in the tropical streams on the island of St. Thomas. These tropical streams are locally called "guts." This species is a predator in the shrimp world and is the largest species of shrimp in the guts on St. Thomas. Macrobrachium carcinus is usually brown and cream in color. M. carcinus is easily identified by its two large claws or pincers. On other island this species have been harvested for food. At one point, this was a food source in the USVI, but the guts are heavily polluted and are no longer considered an edible species. M. carcinus is diadromous, in that it migrates from the marine environment into freshwater bodies like creeks, streams and rivers. less ↑

Xiphocaris elongata also known as the Carrot-nose shrimp or the Yellow rhino shrimp. This species is gray to translucent in color. A gold/yellow line follows from the carapace to the tail on the dorsal side. Nose is also yellow or gold hence the common names. This species is 1 of 3 filter feeder shrimp living in tropical freshwater streams called "guts" on St. Thomas. X. elongata can be observed clinging to rocks or free swimming in the water column in pools in the gut. X. elongata is a herbivore and is non-aggressive shrimp. This species has the ability to climb over barriers reaching pools at high elevations of the gut in St. Thomas. less ↑

Macrobrachium faustinum is 1 of 5 species of freshwater shrimp inhabiting guts in St. Thomas. This migratory species spawns in brackish water or the marine environment. This species has a pelagic life stage before migrating into freshwater bodies as juveniles. This species resembles Macrobrachium carcinus, which also lives in guts in St. Thomas, U.S Virgin Islands. This species is more distinguishable in that it has a claw or pincer that is larger than the other. less ↑