A major component of my dissertation research focuses on testing two hypotheses: (1) that generalist species evolve in environments with highly variable prey availability and (2) that diversification occurs more slowly in generalist lineages. For my research I define a generalist species as one that can eat many types of prey and live in multiple habitats. I have selected the clupeiform fishes (anchovies, herrings, sardines, shads, and their relatives) as a study group to test this hypothesis. This is an ideal group because it contains many species (>350) that differ in the range of prey the consume and inhabit both temporally stable and dynamic, freshwater and marine environments around the world [1][2].
Before I can conduct any analyses, I must know what these fish eat, how the different species in this family are related (the clupeiform family tree), and how prey availability changes through time in the ecosystems they inhabit. I can find some of this information in books and journal articles, but I need to gather lot of it myself by examining specimens that have been preserved using special methods that do not destroy DNA or stomach contents. Therefore, I am collecting and preserving individuals from as many clupeiform species as possible.
Clupeiforms are found in freshwater and marine habitats all around the world, but the greatest concentrations are in South America and the Indo-Pacific (for reasons that are not well understood) [1]. Another researcher, Devin Bloom, has already extensively collected and published on South American clupeiforms. So, while in graduate school I will spend most of my time collecting Indo-Pacific species, for which there are very few materials available. In 2013 I collected in Alabama, USA and Taiwan (ROC) and this year I will be collecting in Taiwan and Australia.
References
[1] Whitehead et al. (1988): Clupeoid Fishes of the World (Suborder Clupeoidei)
[2] Bloom & Lovejoy (2012): Molecular phylogenetics reveals a pattern of biome conservatism in New World anchovies (Family Engraulidae)
Before I can conduct any analyses, I must know what these fish eat, how the different species in this family are related (the clupeiform family tree), and how prey availability changes through time in the ecosystems they inhabit. I can find some of this information in books and journal articles, but I need to gather lot of it myself by examining specimens that have been preserved using special methods that do not destroy DNA or stomach contents. Therefore, I am collecting and preserving individuals from as many clupeiform species as possible.
Clupeiforms are found in freshwater and marine habitats all around the world, but the greatest concentrations are in South America and the Indo-Pacific (for reasons that are not well understood) [1]. Another researcher, Devin Bloom, has already extensively collected and published on South American clupeiforms. So, while in graduate school I will spend most of my time collecting Indo-Pacific species, for which there are very few materials available. In 2013 I collected in Alabama, USA and Taiwan (ROC) and this year I will be collecting in Taiwan and Australia.
References
[1] Whitehead et al. (1988): Clupeoid Fishes of the World (Suborder Clupeoidei)
[2] Bloom & Lovejoy (2012): Molecular phylogenetics reveals a pattern of biome conservatism in New World anchovies (Family Engraulidae)
Left: Anchovies I captured in Alabama with the help of researchers from the University of Southern Alabama during the summer of 2013. The bottom 2 individuals are Anchoa mitchilli and top 6 are Anchoa hepsetus. Right: Keelong fish market 2013 (Yes, I collect at fish markets too!).