Download Procambarus alleni Coloration as Impacted by Diet

Procambarus alleni Coloration as
Impacted by Diet and Environment
Name:
Introduction
The blue morphed Procambarus alleni is one of the most common invertebrates for trade within the
United States aquaculture. The reason for this morph is an autosomal recessive trait that can be attained in
mass quantities through selective breeding. It has been observed that certain species of crayfish have been
able to change their exterior coloration when subjected to different environments. This may be due to the
crustaceans chromatophores, which are light sensitive cells on the crayfish carapace that are able to reflect
the hues of the habitat that the crustacean is placed.
A major pigment in the crayfish’s exterior is astaxanthin which is synthesized from carotene and reacts
with proteins to produce colors. It is felt that part of the genetic enzyme defect that is passed on recessively
causes the body to release uncontrolled levels of astaxathin, giving the Procambarus alleni its blue shade.
This study will examine how environmental coloration and diet effects the crayfish pigmentation.
Methods
Twenty mature specimens of the blue morph Procambarus
alleni will be obtained from a breeder and submitted to a three
week stabilization period in which the invertebrates will undergo
universal conditions to acclimate to their new surroundings before
testing.
Each specimen will then be weighed, measured, and an initial
record of coloration will be documented at two locations on the
body (thorax and posterior dorsal region of carapace), using
common color platelets.
Three control specimen will remain in the stable
monochromatic environment being fed a standard pellet diet. Two
crayfish will undergo no other changes than a high protein diet and
a carotene restricted diet. The fifteen remaining specimens will
each be placed in an environment solely consisting of a single
color based on different chromatophores.
Chromatophores
40x
Yellow - Xanthophores
Red - Erythrophores
Black/Brown – Melanophores
Blue – Cyanophores
White – Leucophores
All other aspects of habitat and behavior will be recorded
including; molting processes, temperature, lighting, water quality,
and general behavioral patterns. At the end and midpoint of a two
month period repeated documentation of weight, size, and
coloration, will take place at which point a conclusion will be
generated and nonparametric statistics made.
References
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Dowell, V. E. and L.P.Winier. 1969. A bilateral color anomaly in the crayfish, Orconestes immunis (Hagen). Proc. Iowa. Acad. Sci., 76:487-492.
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Crustaceana, 20:221.
Procambarus Alleni
Cherax sp. Blue Moon
Cherax Preissii
Protein Synthesis
Predicted Results
The specimens from Set A that are kept in the different colored
environments will begin to display colorations similar to their
background. More importantly the specimen kept in the blue habitat
will have an increase in the vibrancy of its already blue shade.
The specimen from Set B that is on a carotene restricted died will
display the most drastic color improvement. Followed by the
specimen on the high protein diet, and lastly the control specimen
will show the least change in coloration.
Conclusions
The Procambarus alleni is able to adapt
to their environment and change their
coloration in response to their background.
This is a survival technique in order to
camouflage themselves for protection
against predators. In the aqua culture it
would be best to suggest that aquarists use
a blue substrate/gravel mix with their
invertebrates and a carotene restricted diet
in order to achieve ultimate vibrancy in this
species blue hue.