ABSTRACT
Barrens topminnow spawns mainly over clumps of filamentous algae, to which their eggs adhere. Barrens topminnows hatch at about 7 mm as yolk-sac larvae and have median finfolds from which the median fins develop; by the time all remnants of finfold have been absorbed in barrens topminnows, the relative position of the dorsal and anal fins is apparent. The dorsal fin origin of western mosquitofish is behind or approximately even with the insertion of the anal fin; for barrens topminnows, the dorsal fin originates slightly behind the anal fin origin. Initiation of scale development begins at about 14 mm for barrens topminnow. Due to barrens topminnow’s limited range and current status, the opportunity to confuse it with other Fundulus would be reduced. Young barrens topminnows have scattered melanophores over the entire body, which no other sympatric topminnow species exhibits. Original information comes from a population of barrens topminnows from a tributary of McMahan Creek, Cannon County, TN.
