24 
Robert P. Creed, Jr., and Seth R. Reice 
stream that flows through the Duke Forest, in Orange County, N.C., 
approximately 1 1 km NE of Chapel Hill. Madtoms were collected using 
an electroshocker in combination with dipnets, because strong currents 
and the rocky bottom prevented the effective use of a seine. Shocked 
fish were captured as they drifted into two large dipnets (0.5 m X 0.25 
m) placed on the bottom about 0.5 m downstream from the anode ring. 
Fish were collected from September 1982 through August 1983 with 
collection dates approximately 1 month apart (range 27-41 days, x = 33 
days). We restricted collection to a small section of the stream so that 
any observed variation in diet would not be a result of variation in prey 
availability at different sites. 
Because madtoms are reported to be nocturnal feeders (Mayden 
and Burr 1981, Burr and Mayden 1982, Moyle and Cech 1982), collections 
were made between 1 and 2 hours after sunrise. Fish were preserved 
whole in 95% ethanol within an hour of capture. In order to assess 
whether madtoms consumed any prey during the day, fish were collected 
twice on one date (27 July 1983), once in the morning and again 
between 1700 and 1800 hours. 
Prior to gut content analysis, fish were measured (total length in 
mm). Then the foregut and intestine were removed. Visual estimations 
of gut fullness were made for both the foregut and the intestine 
following the methods of Yoshiyama (1980) and Creed (1985). Evaluation 
of gut fullness was not initiated until March 1983. Five levels of fullness 
were used: 0, l A, Vi, 1, 2, of which 0 signifies empty or with traces of 
food, 1 is full, and 2 is distended. Contents of both the foregut and the 
intestine were then removed and examined under a dissecting microscope. 
Prey items were counted and identified to the lowest taxon possible 
(often genus, occasionally species). These data were pooled by season, 
because it was not always possible to sample adequate numbers of 
madtoms in particular months. This was especially true of collections 
made in January and February, when water levels were high and 
effective sampling was difficult. The seasons referred to in the results 
(fall 1982 through summer 1983) encompass the following collection 
dates: fall - 28. IX, 28. X, 7. XII; winter - 6.1, 9. II, 1 6. Ill; spring - 14.IV, 
ll.V, 21. VI; summer - 27. VII, 25. VIII. 
RESULTS AND DISCUSSION 
A total of 53 margined madtoms were sampled for gut content 
analysis. Numbers of madtoms collected in each of the first three 
sampling seasons were about equal (fall N = 10, winter N = 1 1, spring N 
= 12), but about twice as many madtoms were collected during the 
summer (N = 20). 
