University of Wisconsin Digital Collections
Link to University of Wisconsin Digital Collections
Link to University of Wisconsin Digital Collections
Ecology and Natural Resources Collection

Page View

Becker, George C. / Fishes of Wisconsin
(1983)

Bullhead catfish family - ictaluridae,   pp. 693-732 PDF (19.6 MB)


Page 726

726   Bullhead Catfish Family-Ictaluridae 
  Noturus flavus           ) l   }j'        _ 
  BIOLOGY 
  In Wisconsin, the stonecat probably spawns in June 
  or July, and possibly continues to spawn as late as 
August. Spawning begins when the water temper- 
ature reaches 27.8'C (82'F). The eggs are placed un- 
der stones, and are guarded by one or both parents. 
  In New York state, Greeley (1929) found two egg 
masses under flat stones on 13 July at a water tem- 
perature of 27.8°C. Two fishes, probably the parents, 
guarded one mass, and a male was hidden beneath 
the other. About 500 yellow, opaque eggs, 3.5-4.0 mm 
diam, were held together in a round mass by an ad- 
hesive jelly. In western Lake Erie, stonecats spawn 
in early June on bouldery shoals, or in the lower- 
most riffles of tributary rivers (Langlois 1954). The fe- 
males had well-developed eggs on 27 June; each fe- 
male held from 767 to 1,205 eggs. 
  M. Fish (1932) described and illustrated the 20-mm 
stage. In the Wisconsin River (Richland County), 14 
young-of-year averaged 47 (21-61) mm TL in mid- 
August, and on the Platte River (Grant County), a 
single young fish was 32 mm TL on 24 September. 
               .   Range of the stonecat 
     j             * Specimens examined 
                 A Wisconsin Fish Distribution Study (1974-75) 
                   0 Literature and reports 
                   0 Greene (1935) 
   The age and growth of 74 stonecats from Wiscon- 
 sin (UWSP specimens), aged by analysis of the pec- 
 toral spines, are summarized below (Paruch 1979): 
                 TL           Calculated TL at Annulus 
 Age No.of      (mm)                 (mm) 
 Class Fish  Avg  Range     1    2    3     4     5 
0     27      46  29-83 
I     20     102  49-142   55 
II    19     148  88-173   48   100 
III    5     159 146-169   42    88  124 
IV     1     199           54    90  145   163 
V      2     187 185-188   51   72   114   147  162 
  Avg (weighted)           51   95   124   152  162 
In 10 stonecats, collected 9 August from  Kuenster 
Creek (Grant County, the total lengths calculated, to 
the annuli were: 1-52.9 mm; 2-96.4 mm; and 3- 
102.9 mm (Paruch 1979). 
  In the Vermillion River, South Dakota (Carlson 
1966), the stonecat averages 79 mm TL at the end of 
its first year of life, and attains lengths of 99, 114, 
and 137 mm by the ends of succeeding years. The 


Go up to Top of Page