Alabama cave shrimp

The Alabama cave shrimp (Palaemonias alabamae) is species of albinistic, obligate cave shrimp. The species was first collected in 1958 by Dr. Thomas Poulson. They are found only in two caves in the state of Alabama. Due to its small population and limited range, it is considered an endangered species.

After a search of nearly 200 caves in northern Alabama, the shrimp have only been spotted in two, Shelta and Bobcat Caves, both in Madison County, Alabama. Only about 25 members of the species have been spotted between the two caves since its endangered listing in 1988. One reasoning for such a small siting number may be because of the shrimp's coloring, or the lack of. The species is nearly transparent and closely resembles its nearest relative, the Kentucky cave shrimp, only smaller. Some researchers believe the lack of pigmentation indicates that it has survived underground without light for probably thousands of years.

The typical size of the shrimp ranges normally to about a length of only 20 millimeters or 0.8 inches. The female of the species tends to be about .05 inches longer than that of the male and have a longer snout. Characteristics that tell the Alabama cave shrimp from the Kentucky cave shrimp are that it usually lacks abdominal scales, with fewer scales on the back. It also has unfaceted eyes that are unpigmented. The species is a nonselective grazer, feeding on protozoans, fungae, and algae that normally enter the caves through groundwater.

The Alabama cave shrimp has a global status of critically imperiled, due to its being found in 5 or fewer areas. For this same reason, or for some factor making it exceptible to extinction, it has an Alabama state ranking of critically imperiled. Because of these factors, the Alabama cave shrimp has been listed as an endangered species. This was effective October 7, 1988 by the United States Fish and Wildlife Service.

This species became endangered because of habitat degeneration and contamination. High levels of the pesticide DDT were found in Shelta in Bobcat Caves, apparently leakage from drainage ditches. In addition, the decrease in the population of gray bats contributed to the decline of the shrimp. The shrimp used to feed on bat excrements, but now the population has decreased. This species also has a low reproductive rate.