ABSTRACT
Dendrobranchiata currently is composed of two superfamilies, Penaeoidea (families Aristeidae, Benthesicymidae, Penaeidae, Sicyoniidae, and Solenoceridae) and Sergestoidea (families Sergestidae and Luciferidae). Although the monophyly of Dendrobranchiata is rather firmly established, little is known about the relationships among its families. We analyzed 24 taxa of Dendrobranchiata using three different combinations of outgroups, with differing results. In the majority of the most parsimonious trees, Dendrobranchiata, Penaeoidea, and Sergestoidea appear monophyletic, as do the families Aristeidae, Solenoceridae, Sicyoniidae, Sergestidae, and Luciferidae. The families Penaeidae and Benthesicymidae are not monophyletic. Dendrobranchiata is defined by having dendrobranchiate gills, prominent pleonic hinges, larvae hatching as nauplii or protozoeae, and the presence of a petasma in males. Sergestoidea is defined primarily by “lost” characters, including the loss of the exopod on maxilliped 3, the absence of a dactyl on P1, and the related absence of a P1 chela. Penaeoidea is defined by the presence of a tubercle on the terminal article of the eyestalk and the presence of a branchiocardiac carina. There are no clear synapomorphies defining the Aristeidae. Solenoceridae is defined by the presence of a postorbital spine and the presence of a distolateral projection on the male pleopod 2. Sicyoniidae is defined by many characters, including the presence of an ocular stylet. Sergestidae and Luciferidae also are defined by many characters, such as the presence of a clasper organ on the male antenna 1 in the sergestids and the brooding of eggs on the female pereopods in luciferids.
