Buckwalter, J.D., P.L. Angermeier, J. Argentina, S. Wolf, S. Floyd, and E.M. Hallerman. 2019.
Drift of larval darters (Family Percidae) in the upper Roanoke River basin, USA, characterized
using phenotypic and DNA barcoding markers. Fishes 4(4), 59; doi:10.3390/fishes4040059.
Larval ﬁsh ecology is poorly characterized because sampling is diﬃcult and tools for phenotypically identifying larvae are poorly developed. While DNA barcoding can help address the latter problem, ‘universal’ primers do not work for all ﬁsh species. The Roanoke River in the southeastern United States includes seven darters (Family Percide: Tribe Etheostomatini). We made 393 collections of larval ﬁshes in 2015 and 2018, examined darter larvae for morphometric and pigmentation traits, developed PCR primers amplifying darter DNA, and evaluated three gear types for collecting larval darters. Ampliﬁed DNA sequences for 1351 larvae matched archived mitochondrial cytochrome oxidase I sequences for darters occurring in the ecosystem. Larval darters were classiﬁed to genus with 100% accuracy using the ratio of pectoral ﬁn length to body length; however,identiﬁcationtospeciesusingmorphometricsalonewassubjecttoamisclassiﬁcationrateof 11.8%, which can be resolved by considering pigmentation patterns. Gear-types varied considerably in their capture eﬃcacy for larval darters; most Percina larvae were collected in drift nets. Larval Percina species appeared in the drift before Etheostoma species in both study years. Application of molecular genetic and phenotypic tools to larval ﬁsh identiﬁcation can advance understanding of larval darter ecology.