Seasonal Diet of Margined Madtom 
25 
Table 1. Distribution of 53 margined madtoms collected from New Hope 
Creek, Orange Co., N.C., by size class and season. 
Season 
Size class (mm) 
<31 
31-60 
61-90 
91-120 
Fall 
0 
6 
1 
3 
Winter 
0 
5 
1 
5 
Spring 
0 
3 
5 
4 
Summer 
1 
6 
9 
4 
Madtoms, which ranged from 19 to 113 mm, were assigned to four 
size classes (Table 1). Fish 31 mm or longer were collected throughout 
the year. In fall and winter samples, however, most fish were in the 
40-50 mm and 95-105 mm ranges, which closely match the ranges of 
Clugston and Cooper (1960, figure 2) for age 0+ and 1+ fish during fall 
and winter months. During the spring and summer we collected a 
number of madtoms from an intermediate size class (61-90 mm). 
Clugston and Cooper collected madtoms in that same size range during 
the summer growing season. The data suggest that madtoms in the 
intermediate size class in our study are probably age 0+ fish growing to 
age 1 size. We collected only one young-of-the-year madtom, less than 
31 mm long (19 mm), in July. 
Captured madtoms almost always contained prey. The only 
exceptions were two small fish (40 and 38 mm) collected in January. In 
general, fish collected during the winter contained fewer prey than those 
sampled during the rest of the year (Table 2). Ninety percent of the fish 
collected from March through August (N = 31) had a foregut fullness of 
l /i or greater. Most fullness values (84%) for the intestine were l /i or less. 
These data suggest that the madtoms had fed throughout the night and 
that processed food was starting to move into the intestine. Four of the 
five madtoms sampled on the morning of 27 July had a foregut fullness 
of 1 and the fifth had a foregut fullness of l A\ all had an intestinal 
fullness of l /i or less. Three of the five individuals sampled that 
afternoon had no prey in the foregut, and two contained 8 and 42 prey 
items, respectively; all had an intestinal fullness of x /i or greater. Some 
prey from the afternoon foregut samples were not broken up, which 
suggests that they had been consumed recently. In general, however, 
intestinal fullness increased from morning to afternoon. Therefore, 
although the general trend was for nocturnal feeding, some madtoms 
appeared to take prey during the day. 
