Barcoding the fishes of Mesoamerica and the Caribbean

Why barcode Neotropical fish? Leverage local enthusiasm for DNA-based scientific inference to promote ichthyological discovery Use ichthyological discovery and interest in Neotropical fish to accelerate molecular systematics training for Latin American scientists Promote phylogenetic analysis of Neotropical fish through availability of high- quality DNA BOLD facilitates collaboration among geographically dispersed investigators GENBANK barcodes provide an additional window into a student’s science COI barcodes provide an additional ~600 bp of DNA sequence data, which in combination with additional genes distributed around the mitochondrial molecule (e.g. cyt b and ATP synthase) increase likelihood of detecting pseudogenes and contribute to the 2000 bp “needed” for a robust phylogenetic estimate of mtDNA relationship

Characidae - Astyanax (“aeneus”, includes Bramocharax) - Brycon (‘striatulus’ group, includes chagrensis, behreae, sp. nov. “Bocas”, guatemalensis) - Hyphessobrycon - Roeboides Heptapteridae - Rhamdia guatemalensis (includes wagneri) - Rhamdia laticauda (includes reddelli, parryi, rogersi, cabrerai, nicaraguensis ) Gymnotidae - Gymnotus Synbranchidae - Synbranchus + Ophisternon Study taxa

Miller (1966), Myers (1966) Mesoamerica colonized by primary freshwater fishes following the Pliocene completion of the Panama land bridge. Evidence: Low species diversity of primary freshwater fish species in nuclear Mesoamerica (north of Lake Nicaragua) in comparison to secondary freshwater fishes (Cichlidae, Poecilidae, etc.). Bussing (1976, 1985) Mesoamerica colonized by freshwater fishes in two waves: “Old Southern” (early Tertiary) and “New Southern” (Pliocene). Evidence: Broad distribution and species richness of “Old Southern” clades, in comparison to narrow, southern distribution and species poverty of the “New Southern” clades.

Testing the alternative hypotheses of Miller and Myers versus Bussing is of general interest for understanding the role that evolutionary time plays in: geographic range expansion following invasion speciation alternative outcomes in the evolutionary assembly of a biota

Marine Geminates Gymnotus Rhamdia guatemalensis Brycon Roeboides (10 genera)

Rob. 10 MY2 MY20 MY3 MY1 MY PimA. Ast. BRW. Hyp. Gym. Syn. Cyp. Bra. RaL. RaG. PimB. FINAL CLOSURE OF THE PANAMA LAND BRIDGE: MILLION YEARS BEFORE PRESENT BRE. 5 MY Relative Time Line PRESENT

10 MY2 MY20 MY3 MY1 MY FINAL CLOSURE OF THE PANAMA LAND BRIDGE: MILLION YEARS BEFORE PRESENT 5 MY Relative Time Line PRESENT Rhamdia guatemalensis Brycon striatulus group Late colonists with extreme ranges

10 MY2 MY20 MY3 MY1 MY FINAL CLOSURE OF THE PANAMA LAND BRIDGE: MILLION YEARS BEFORE PRESENT 5 MY Relative Time Line PRESENT Brycon argenteus group Brachyhypopomus Early colonists with range expansions cut short

Miller and Myers vs Bussing: The former authors had it right and all primary fishes found in northern Mesoamerica dispersed from South America around the time of the Pliocene (~3 MYA) completion of the Panama landbridge. geographic range is not strongly influenced by the time since colonization of Mesoamerica. speciation is not evident in Mesoamerica primary freshwater fishes in spite of significant phylogeographic structure, phylogenetic evidence indicating that dispersal is not strongly limiting, and ‘experimental’ evidence (not shown) demonstrating that communities are not saturated. evolutionary assembly of the Mesoamerican freshwater fish fauna, and striking differences with South American ichthyofauna is explained, in part, by the late arrival of primary freshwater fishes to Mesoamerica.