Molecular Analysis of the Mating System of a Population of Fantail Darter (Etheostoma flabellare) in Bates Fork, Greene Co., PA

In May 2013, we examined the mating system of the Fantail Darter, Etheostoma flabellare, from a population inhabiting Bates Fork, a small tributary of the Monongahela River in Greene County, PA. Guarding adult male Fantail Darters excavate an area under a flat rock in moderately flowing rifles. Females select a male or his territory and deposit clusters of eggs on the underside of the nest rock. The guarding male provides all parental care. The locations of 23 nests were mapped over a 139m2 stream segment before collecting embryos and attending males for a genetic parentage analysis. DNA was extracted from embryos and adults representing five nests and parental relationships were established using three microsatellite loci. The average number of eggs in each nest was 349, with a range of 50 – 817 eggs. The average minimum number of females that contributed to each nest was 5.8 females. In two of the five nests, the guarding male was providing foster care to a small number (2-5) of embryos, indicating low-level cuckoldry events. No evidence for nest takeover was detected