Research Interests

I am an ichthyologist interested in understanding the natural history of the world's fishes.  While most of my own work centers around the evolutionary biology of fishes - their systematics, taxonomy, and historical biogeography - I enjoy collaborating with scientists active in other areas of study such as paleontology, physiology, genomics, ecology, and behavior.  I like to think of my work as integrative, as this is the best approach to understanding as much as we can about these organisms.

I am primarily interested in neotropical freshwater fishes of Mexico, Central & South America.  Over several decades of collecting throughout the region, as well as the continuous development of new analyses, we are now able to incorporate many types of studies and approaches to better understand the diversity and distributions of these fishes.  Nearly every aspect of my research is collections-based and relies heavily on specimens housed in museums, as well as my own recent collections.

In addition to my work on fishes, I am also deeply interested in the use of morphological characters in phylogenetic reconstruction, and in depth studies of incongruences between morphological and molecular hypotheses of phylogeny.

Systematics & Taxonomy of Neotropical Fishes
A large part of my research focuses on understanding the evolutionary relationships among fishes, primarily from the neotropics.  With robust phylogenetic hypotheses for groups of fishes, questions regarding timing and rate of evolution, as well as evolution 
of different characters, can be addressed.  Over 500 species of neotropical cichlids live in the freshwaters of North, Central, and South America.  These fishes possess incredible diversity in their behavior, morphology, and ecology.  I am interested in the evolution of these fishes, and most of my current work focuses on herichthyine cichlids from northern Middle America.

Biogeography in Middle American Rivers
In order to have robust investigations into the historical biogeography of organisms, we need thorough studies on the phylogenetic history of those organisms.  I am interested in using phylogenies to make inferences about the biogeographic history of specific lineages, as well as search for patterns that may be congruent across multiple lineages.  Of particular interest is the congruence between biogeographic patterns and the geologic history of the landmasses where these organisms occur.  Most recent efforts have focused on historical biogeography across lineages of freshwater fishes in Middle America.

In addition to historical biogeography, I am also interested in more small-scale (phylogeographic) investigations.  Many studies have shown interesting phylogeographic patterns across neotropical freshwater fishes.  Current work is focused on understanding phylogeography and gene flow across widespread freshwater fishes in Middle America, with a particular interest in the physiology of salinity tolerance, and the consequences on marine dispersal.

Ecomorphology & Body Shape Evolution
More information coming soon.