78 
Burr, Kuhajda, Dimmick, and Grady 
barbels, rudimentary nasal barbels, and darkly pigmented retinae; small 
pectoral and pelvic fin buds; and a continuous posterior fin fold 
heightened in the regions of the anal and dorsal fins, and with 
rudimentary caudal and anal rays (Fig. 7). A sprinkling of melanophores 
occurred on the head and along the dorsal myomeres. Hatchlings of N. 
furiosus exhibited tightly cohesive schooling behavior. Larvae in later 
stages of development were not found. Early post-hatching larvae of N. 
furiosus closely resembled N. nocturnus (Burr and Mayden 1982b) and 
N. miurus (Burr and Mayden 1982a) in shape, pigmentation, and 
overall developmental features. Early post-hatching larvae of other 
species of Noturus are more heavily pigmented when compared with N. 
furiosus (e.g., N. exilis, Mayden and Burr 1981; N. flav at er, Burr and 
Mayden 1984). 
The smallest juveniles known are 17 mm SL, and they have the 
body shape and pigmentation pattern typical of adults. 
Diet. A total of 200 stomachs of N. furiosus were examined; 88 
were empty, 18 had unidentifiable disgested material, and 94 contained 
some food. The large percentage of empty stomachs is probably a 
sample bias resulting from many daytime collections. Madtoms feed 
primarily during the evening with peaks at dawn and dusk (Mayden and 
Burr 1981). 
Dipteran, ephemeropteran, trichopteran, coleopteran, and odonate 
larvae or nymphs compose more than 95% of the total food organisms 
(Table 3). Dipteran larvae and ephemeropteran nymphs were the most 
commonly eaten food source. Chironomid larvae accounted for 91% of 
the dipterans eaten, with the remainder being culicid and simuliid 
larvae. Ephemeropteran nymphs included members of the families 
Baetiscidae, Heptageniidae, and Caenidae. Larvae of Hydropsychidae 
were the predominant (69%) representatives of Trichoptera. Elmid 
larvae made up 95% of the coleopterans, and almost all of the elmids 
were members of the genus Stenelmis , with only one individual of 
Dubiraphia represented. Odonates included nymphs of the genus 
Hagenius, in the family Gomphidae, and one representative of 
Coenagrionidae. Nematodes found in the stomachs were possibly 
parasitic. Four individuals had large fish scales in their stomachs, 
probably indicating benthic scavenging activities. Individual madtoms 
ate a variety of organisms; one had representatives of six different taxa 
in its stomach. Several individuals had sand grains and plant material 
mixed in with their food, which probably was ingested incidentally. 
Larger individuals ate larger food items (Table 3). The relatively 
small-sized dipteran larvae decreased in the diet with increasing size of 
the madtom. Percentages of larval dipterans in the diet of the three size 
groups of madtoms listed in Table 3 varied from 35.5 to 26.8 to 0. In 
