A phylogenetic study of the shrimp genus Palaemonetes Heller 1869 from North America (Crustacea: Decapoda)

The broad research objective of this study is to understand the systematic relationships of the species within the genus Palaemonetes from North America. This will provide a framework to increase our knowledge of this important part of the aquatic food chain, as well as provide a mechanism for understanding more about the biogeography and the ecology of North America. The specific issues to be examined in this study are: (1) the development of hypotheses of systematic relationships among species of Palaemonetes from North America; (2) whether the freshwater species do form a monophyletic group as proposed by Sollaud (1923) and Strenth (1976); (3) whether following the hypothesis by Holthuis (1952), and re-enacted by Webb (1980), P. antrorum should be elevated to a subgenus (Alaocaris) and separated from the other species of North American Palaemonetes; (4) whether P. holthuisi should be elevated to a new genus. 10 Calathaemon, as proposed by Bruce (1993) is supported by the data; (5) whether the hypothesis by Dobkin (1965, 1971) that P. kadiakensis is a recent immigrant into the freshwater environment is upheld; (6) whether the origin of the North American species of Palaemonetes was in salt or freshwater; and (7) what the potential role of biogeography in the evolution of the genus Palaemonetes.