Dr. Sparks’ research focuses on the systematics, evolution, and biogeography of freshwater and nearshore marine fishes.  Current projects include the evolution and function of sexually-dimorphic bioluminescent signaling systems in ponyfishes (Leiognathidae) and other bioluminescent marine fish clades, the origin(s) and biogeography of Madagascar's freshwater and nearshore marine fishes, and synthetic studies investigating the biogeographic history of the Western Indian Ocean.  Dr. Sparks is also conducting phylogenetic studies, combining both morphological and molecular evidence, of cichlids, atheriniforms (silversides), and sicydiine (rock-climbing) gobies.  He is collaborating with microbiologists to investigate host-symbiont coevolution in ponyfishes in which light is produced by symbiotic luminescent bacteria housed in a complex circumesophageal light organ.  Recent fieldwork includes biotic surveys and inventories of both freshwater and nearshore marine fishes in Madagascar, the Indo-Pacific region, South America, and the Caribbean.