Has Detailed Life History and Ecology of the Barrens Topminnow, Fundulus julisia, Williams and Etnier (Pisces, Fundulidae) Helped to Prevent its Extinction?

Patrick L. Rakes¹ and Peggy W. Shute^1,*

¹Conservation Fisheries, 3424 Division Street, Knoxville, TN 37919. *Corresponding author.

Southeastern Naturalist, Volume 24, Special Issue 13 (2025): 41–60

First published early online: 26 August 2026

Abstract
We report Fundulus julisia (Barrens Topminnow [BTM]) life history from field investigations during 1983–1985 on the Barrens Plateau in central Tennessee. Populations studied included 1 each in the Cumberland River and Tennessee River drainages. The BTM feeds on aquatic insect larvae and other invertebrates. BTM’s extended breeding season includes bimodal peaks, and its eggs are attached to aquatic plants. First-year growth is rapid; maximum lifespan is 4 years. Few individuals survive to spawn more than once in the wild. Gambusia affinis (Western Mosquitofish) is a primary threat. Captive BTM assurance colonies may be key to successful future reintroductions following landscape management actions. We highlight the importance of this basic ecological information in preventing BTM extinction.

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