The slender-headed darter was taken at all stations but was more
abundant in the Neosho than in the Marais des Cygnes. The lower Marais
des Cygnes, however, was the only station with a relatively large
population in 1957. Slender-headed darters were rare in the Neosho River
in 1957 and did not become common until 1959.
The largest population was found at the upper Neosho station in 1959.
This darter occurs most frequently in swift water over gravel bottom,
but was taken in various habitats, including an intermittent pool at the
upper Neosho station on 7 September, 1957.
At the middle and lower Neosho stations, considerably greater numbers
were taken in June, July, and early August than in May or late August.
The abundance in my collections diminished from a peak in early July, to
scarcity in late August.
Young-of-the-year were taken at the lower Neosho station on 1 July, 1959
(and subsequently), in moderately fast water over gravel. On 21 August,
1958, a ripe female (eggs stripped easily) was the only slender-headed
darter present in a collection from riffles at the middle Neosho
station.
#Percina caprodes# (Rafinesque)