30 Alvin L. Braswell and Ray E. Ashton, Jr. 



Virtually all larval specimens were collected by netting in leaf beds, 

 and their representative diet may be biased in favor of prey available in 

 the beds. Whether larvae are more dependent on leaf beds than are 

 adults, or whether collecting techniques currently used are inadequate to 

 collect them elsewhere, is currently unknown. As previously stated, 

 adults were once thought to rely heavily on leaf beds. 



Necturus lewisi, then, is an opportunistic feeder whose diet proba- 

 bly varies from season to season as changes in composition and abun- 

 dance of the prey community occur. The data presented here should 

 indicate their diet from January to mid-April, but additional investiga- 

 tion is needed to determine just how much seasonal variance their diet 

 displays. 



The abundance of certain potential prey in N. lewisi sites, and the 

 low incidence of these items in digestive tract contents, probably reflect 

 the difficulty encountered by the salamanders in capturing certain spe- 

 cies. Examples of abundant and highly mobile potential prey are cray- 

 fish, palaemonid shrimp, amphipods, plecoptera nymphs, odonate nai- 

 ads, and small fish. 



The great similarity in diets of N. lewisi and N. punctatus would 

 certainly seem to encourage competition between these two species, 

 especially in sites where food is scarce. However, the year-round diet of 

 N. punctatus is no better known than that of N. lewisi. Also, N. puncta- 

 tus routinely exploits smaller Coastal Plain streams than N. lewisi does; 

 the major area of sympatry between them is along the Fall Line Zone. 

 Investigation of the habitats and habits of N. punctatus in adjacent 

 drainages where N. lewisi is absent could reveal more about competition 

 between the two species. Necturus punctatus may possess greater toler- 

 ances for oxygen and temperature ranges, ph levels, and drought 

 conditions. 



The wide distribution of N. lewisi in the Neuse and Tar River 

 drainages argues against Endangered or Threatened status at this time. 

 However, a status of Special Concern may be warranted due to N. lewi- 

 si's need for large streams with relatively clean, flowing water. Stephan 

 (1977) suggested that N. lewisi be considered a species of Special Con- 

 cern, based on its restricted distribution and susceptibility to environ- 

 mental degradation. Some distributional gaps that may be attributable 

 to effluents were previously indicated. Large reservoirs and stream 

 channelization cause additional loss of suitable habitat. The increasing 

 industrial and municipal growth in areas influencing the Neuse and Tar 

 River drainages may have a serious impact on N. lewisi, as well as other 

 unique species with similar habitat requirements, unless informed mea- 

 sures are taken to adequately protect their riverine environment. 



