Two races of Etheostoma flabellare flabellare Rafinesque from the Roanoke River of Virginia and the Neuse River of North Carolina

Abstract

A taxonomic study has been made of two closely related races of Etheostoma flabellare flabellare Rafinesque, one from the Roanoke River of Virginia and the other from the Neuse River of North Carolina. They are compared in twenty-three characters (scalation, ray counts, and color marks). For eight characters, the Roanoke sample has been divided into its component groups (the Blackwater and Pigg river samples). These are compared to each other and to the Neuse sample.

Four new characteristics are described. The shape of the line behind the eye is rated as rectangular or 8-shaped. The shape of the spots on the caudal fin is rated as solid or hollow. Three major color patterns are described; one of which is a juvenile pattern and the others are characteristic of males and females. In respect to belly scalation, three categories have been established which are dependent upon the extent of development of the scale row along the ventral mid-line. These are as follows: totally scaled, partially scaled, and naked.

The Roanoke and Neuse fantail darters differ most in seven characters. These are as follows: total and pored scales lateral line, scales across belly, belly scalation, shape and number of spots caudal fin, and the persistence of juvenile color patterns in the adult Neuse female.

Paedomorphosis, in the Neuse fantail, accounts for most of the major differences between the populations.