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



(13) type of bait in trap or on hook; 



(14) caught by trap, hook, or net. 



All Trap Site Data and Captured Animal Data were coded and 

 entered into the North Carolina State Government IBM 370/ 168 main 

 frame computer for SAS analysis. Frequency tables were constructed 

 for the various environmental and physical parameters to demonstrate 

 relative capture success for differing factors. Duncan's Multiple Range 

 Test was used to ascertain significant differences in capture success for 

 different bottom types, stream depths, stream widths, flow rates, levels 

 of precipitation, turbidities, stream categories, maximum and minimum 

 stream temperatures, rises or falls in temperatures, and rises or falls in 

 water levels. 



Necturus voucher specimens were deposited in the lower vertebrate 

 collections of the North Carolina State Museum of Natural History 

 (NCSM), and most major collections in the United States were surveyed 

 for information on N. lewisi specimens. In addition to NCSM, collec- 

 tion acronyms used herein are: American Museum of Natural History 

 (AMNH); Carnegie Museum (CM); Duke University (DU); E. E. Brown 

 personal collection (EEB); Field Museum of Natural History (FMNH); 

 Museum of Comparative Zoology (MCZ); Tulane University (TU); 

 University of Florida/ Florida State Museum (UF/FSM), and National 

 Museum of Natural History (USNM). 



RESULTS 



A total of 361 sites was sampled for N. lewisi during about 7 

 months of field work. Sampling efforts totalled 757, and included 

 15,893 trap days, 2,009 hook days, and an estimated 350 hours dipnet- 

 ting. Positive sites for N. lewisi numbered 116, which was 32% of the 

 surveyed sites. A few positive sites duplicated older records, but most 

 represented new localities. From these sites 208 specimens (58-173 mm 

 SVL, mean = 130 mm) were caught in minnow traps, 5 (129-154 mm 

 SVL, mean = 143 mm) on set hooks, and 82 (21-120 mm SVL, mean - 

 42 mm) in dipnets. Thirty additional specimens were found dead after a 

 toxic chemical (NaOH) spilled into the Neuse River on 10 July 1980. 



An average of 44 trap days was expended per site. In sites positive 

 for N. lewisi, one was caught in a minnow trap for every 24.5 trap 

 days. Occasionally, traps were set in the morning and revisited during 

 the afternoon of the same day; these diurnal trapping periods produced 

 no Necturus. Shrimp and chicken liver were the most frequently used 

 baits in minnow traps, and both seemed to work about equally well. 

 Necturus often engorged themselves with the bait. Dipnetting was most 

 productive where debris, mostly leaves, accumulated around obstruc- 



