Crayfish Sexual Dimorphism

This laboratory report provides an insight into the sexual dimorphism of a crayfish in form size. This follows an experiment of measuring the chela and cephalothorax lengths in both the male and female crayfish. From the results obtained from the experiment, differences sizes of the crayfish are depicted and exhibit sexual dimorphism in the crayfish. The difference in sizes between the two genders of the crayfish is an adaptative measure resulting from changes in the reproduction potential.

Introduction
This report aims at analyzing sexual dimorphism and specifically in crayfish in this particular report. Deriving from its definition, sexual dimorphism can be viewed as the occurrence of morphological differences between the genders that are not directly related to reproduction. Sexual dimorphism depicts a notable difference in size or appearance between the sexes of an animal in addition to difference between the sexual organs themselves. In this case sexual dimorphism demands close scrutiny as it does not occur in all species and when it does, it can be to a large extent be related to differences in gender in reproductive potential. The specific interest for biologists in sexual dimorphism in crayfish lies within the fact of whether the organism is capable giving rise to viable offspring following the sexual dimorphism. In the case of sexual dimorphism in crayfish where they explicit different reproductive potential, they have to adopt reproductive strategies to ensure that they give rise to viable offspring.
Methods
In trying to determine the form of sexual dimorphism exhibited by the crayfish there is some data base on different types of lengths of the crayfish. The first step is to collect and write down the specific chela length of both the male and female crayfish. The second step is to find out the cephalothorax length which can also be defined as the body length of the organism which is also done for both genders (Fukukawa, Mutuku and Munene 26). The final set of data to collect is the chela/cephalothorax length which consist both the chela and cephalothorax lengths which are exhibited in form of a ratio. Consequently, it is vital to determine the mean, standard deviation and number of samples examine for each of the given sets of data. The number of organisms examined for each set of data should be equal (Benzer, Benli and Recep 209). Collection of the numerical data is with an aim of finding out the manifestation of sexual dimorphism through difference in size whereby either the males are larger than the females or the females are larger than the males.
Results
Based on the numerical data, it is a clear indication that the data flaunted is different for the different organisms exhibited in each classification in the table. This creates the need to calculate a mean and standard deviation for the whole set of data in each of the columns. From the mean and standard deviation it is easier to fathom the general size of each gender in the various categories demonstrated. By use of the mean of the 49 organisms in either the male or female category, it is evident that generally the male crayfish has a larger chela than the female while the female has a larger chephalothorax or body than the male crayfish. For the chela/body ratio, the males have a higher ratio than the females.
Discussion
From the results on size of chela and cephalothorax obtained, it is possible to prove the aspects of sexual dimorphism in crayfish on the basis of difference in size. The adaptations in form of size in sexual dimorphism are with reference to the differences in reproductive potential. Both the male and female crayfish therefore have to come up with strategies to maintain the fitness of their offspring, which can be defined by the quality and quantity of the offspring. From the differences in size, it is clear that the adaptive strategy undertaken by the male crayfish is that of having a longer chela while that of the female is having a longer chephalothorax than the male.