Pelagic larval duration (PLD) can influence evolutionary processes ranging
from dispersal to extinction in aquatic organisms. Using estimates of PLD
obtained from species of North American darters (Percidae: Etheostomatinae),
we demonstrate that this freshwater fish clade exhibits surprising variation in
PLD. Comparative analyses provide some evidence that higher stream gradients
favour the evolution of shorter PLD. Additionally, similar to patterns in
the marine fossil record in which lower PLD is associated with greater extinction
probability, we found a reduced PLD in darter lineages was evolutionarily
associated with extinction risk. Understanding the causes and consequences
of PLD length could lead to better management and conservation of organisms
in our increasingly imperiled aquatic environments.