Alabama Cave Shrimp - BIO203
Conjunction Junction Function:
The Alabama
Cave Shrimp can be described as a clear, colorless organism
(Cooper and Cooper 2010). Ranging in length from approximately
fourteen and a half to twenty millimeters, (Copper and Cooper
2010) the Alabama Cave shrimp is comparable to the size of the
diameter of an average marble.
Due to the species risk of
becoming extinct, the Alabama Cave Shrimp is often unable to be
held in fear of stressing the fragile organism (McGregor, et al.
2005). More information on the topic of extinction is
provided on the Facts
page. Without the ability to handle the organism, the
information regarding the size, shape, and structure of the body
are limited and less research has been conducted on this animal relative to
many other organisms. One way scientists may be able to
investigate the size of the Alabama Cave Shrimp without touching
them is through their egg size because egg size is related to
the size the organism will be when reaching the adolescent age
(Meireles et al. 2013) (Click
here for more information on the reproduction of these
organisms).
The Alabama Cave Shrimp has a chitin
exoskeleton just like many other organisms including
Tabanus
longiglossus,
Sceliphron caementarium, and
Psilocybe cubensis
for protection purposes (For more information see Insect Anatomy Basics).
Muscles are
located within the exoskeleton and on the outside (Insect
Anatomy Basics). The muscles on the outside are attached to the
exoskeleton in order to make the Alabama Cave Shrimp be able to
move (Insect Anatomy Basics). This mobility is important in
order for the cave shrimp to find food, hide from predators, and
adapt to changing water levels (Insect Anatomy Basics). Also,
three main segmented body parts are important including the head, thorax,
and abdomen in all arthropods (Insect Anatomy Basics). The head
is made up of the eyes, mouth, and antennae (Insect Anatomy
Basics). The antennae are needed for sensory processing of the
surrounding environment in all of the five senses such as touch
and taste (Insect Anatomy Basics). The thorax contains the
muscles for the movement of the legs (Insect Anatomy Basics).
The abdomen is contains important systems including the
digestive and reproductive (Insect Anatomy Basics).
The closet relative to the Alabama
Cave Shrimp is the Kentucky Cave Shrimp. Please check out the
classification page for
more details. Based on the
information published currently on the internet, genetic testing
has not taken place between the two species (Bibb et al. 2006). Overall, the Alabama Cave Shrimp is smaller in size in
many different aspects of the body compared to the Kentucky Cave
Shrimp (Cooper and Cooper 2010). 
Some of these differences
include length of legs, differences in spines on shell, and the
placement of the eye (Jacobson and Hartfield 1997). In both
species, females are larger in size than males (Cooper and
Cooper 2010). The obvious difference between the males and
females suggests evidence for the concept of sexual dimorphism
in the species (Cooper and Cooper 2010). Sexual dimorphism can
be seen in other species in aspects such as behavior, size and
color such as a male peacock puffing out his feathers to impress
the female. Sex ratios have been estimated to be a one to one; however, finding enough Alabama Cave Shrimp to accurately
count is a difficult and inaccurate process (Jacobson and
Hartfield 1997).
August is the
best time of the year to look for the Alabama Cave Shrimp. Other
months such as February, March, and April have had limited
sightings. Due to the amount of
water in the cave from flooding, the Alabama Cave shrimp tries
to move to a dry, safe environment
in the back of the cave(McGregor et al. 2005).
The amount of rainfall
causes higher amounts of water inside the cave (McGregor
et al. 2005). Even though the Alabama Cave Shrimp is able to
live in wet areas, they are often found lying upside down on the
surface of the water (Cooper and Cooper 2010).
If too much water
floods into the cave all the way up to the top, the Alabama Cave
Shrimp will need to find a new habitat by moving deeper into the
cave where water levels are lower and allows the organism to
freely float on top of the surface of the water. This is a
behavioral adaptation caused by changes in the environment
(McGregor et al. 2005).
The Alabama Cave Shrimp can only be found in part of the cave that is entirely dark. Species living in extreme darkness are called troglobites (Guido et al. 2005). To get a better understanding of the cave check out the habitat page. By studying organism in the dark, scientists are able to look at the adaptations found within species to deal with the absence of light (Klaus et al. 2013). This helps to compare organisms that live in the light to organism that live in complete darkness just as the Alabama Cave Shrimp’s habitat (Klaus et al. 2013).
On our next page, Reproduction, you can learn about the life history and reproduction of the Alabama Cave Shrimp.