How might the shrimp-goby relationship have evolved? Since the invention of S.C.U.B.A., divers have been able to document a plethora of gobies that make association, whether obligate or facultative with snapping shrimp in the genus Alpheus. Currently there are over 70 species of gobies that have been found with shrimp and the number will surely grow as more in-depth studies are conducted in the marine environment (see Taxonomy). Was there one shrimp and one goby that formed a pair and subsequently all our current species evolved, or has this phenomenon arisen several times throughout the course of evolution.
Answering questions on the evolution of a species is difficult if not nearly impossible. Several generations must pass in a confined enviroment for a researcher to even attempt to see changes in behavior. In the case of the shrimp goby, it seems that the relationship has evolved from a need to escape predation, both for the shrimp and the goby. The studies by Thompson (2004) and Nelson (current study), have proven that predation does effect the behavior and population dynamics of the pair. With this information a given now, how is the need for pair formation governed?
Karplus (1992), studied a facultative relationship off Key Biscayne Florida. In his study he concluded that this was probably the first stage in the formation of a pair. Though a process of natural selection, coevolution could then occur. While this is just a theory, it is a step forward in understanding the evolution of hte shrimp goby.