Diagnostic Physical Characteristics

Due to the multitude of similarities between species of the genus Cymodoce, it is advisable to determine whether the Isopod is even in the family Sphaeromatidae. This is easily achieved by collecting the individual and seeing if it is capable of enrolling itself into a sphere.  A suite of requirements for each of the labelled parts below (Figure 2) is detailed in depth when identifying individuals to species level. Crustacea are notorious for their associated  in depth terminology and as such, use of identification keys for the inexperienced proves exceptionally challenging. Often the overall body shape or shape of the Pleotelson will be a distinct characteristic from which species can be excluded or identified if imagery is available. 

For this family of Isopods a fantastic online resource containing free publications and imagery is available to assist with identification- Sphaeromatid Isopods Worldwide (http://isopods.nhm.org). Access to a labelled diagram detailing basic parts (seen below), live and fixed specimens greatly assists in identification below genus level.