Carolina Madtom 
83 
water snakes of the genus Nerodia. However, most predation on N. 
furiosus probably takes place during the larval stage. In other madtoms, 
removal of guardian males from nest sites results in rapid loss of young 
to fishes and crayfishes (Mayden et al. 1980, Mayden and Burr 1981). 
Presently, N. furiosus is placed in the category of special concern 
on North Carolina’s list of endangered and threatened animals (Bailey 
et al. 1977); it is only being considered for listing by the Department of 
the Interior. Nonetheless, fisheries biologists need to be aware of the 
vulnerability of the species to sampling techniques. In the early 1960s, 
numerous collections of N. furiosus were made from the Tar and Neuse 
drainages using the ichthyocide rotenone (Bayless and Smith 1962, 
Smith and Bayless 1964). Unfortunately, a majority of these rotenone 
collections were made in June and July, during the breeding season of 
N. furiosus. Because ichthyocides are extremely effective in killing 
madtoms, we believe that the indiscriminate use of rotenone in North 
Carolina stream surveys should be discouraged. Careful regulation and 
monitoring may even be justified. 
The general biology of N. furiosus as outlined here is similar to that 
in previous reports of other species in the genus. There are, however, 
two important aspects of reproduction in Noturus that remain unresolved. 
Several authors (Menzel and Raney 1973, Mayden and Burr 1981, 
Walsh and Burr 1985) have presented circumstantial evidence that 
females in some species of Noturus may spawn with more than one male 
in a breeding season. In several species, the mean number of vitellogenic 
oocytes is about twice the mean number of embryos found in complete 
broods. In this study, the mean number of vitellogenic oocytes (126.3) 
was somewhat less than the mean number of embryos (152.0) from 
complete broods of N. furiosus. Because of the positive correlation of 
female body size with fecundity, we assume that polyandry does not 
occur in this species. This assumption is supported by the results Blumer 
(1985a) reported from field and laboratory experiments with a related 
species, the brown bullhead, Ictalurus nebulosus. 
One additional aspect of reproduction that remains unresolved in 
Noturus is the contribution of females to parental care of embryos and 
larvae. In all known studies of Noturus , including this one, only males 
have been found guarding embryos or larvae. Because males generally 
do not feed during the nesting and care-giving period they sustain a 
greater cost of care giving (starvation and therefore reduced future 
reproduction) than do males aided by their mates (Blumer 1985b). 
Although a great deal has been learned about the natural history of 
madtoms in the last five years, we still lack basic knowledge of 
(1) spawning behavior, (2) nest construction (if any), (3) social behavior, 
(4) contribution of females in parental care of embryos and larvae, 
