CATFISH GENUS NOTURUS RAFINESQUE 29 



extends later into the year than in the north, his two smallest groups 

 could easily have hatched the previous year rather than only one 

 group resulting from the previous years spawning activity. 



The species are nocturnal and all probably spawn in at least relative 

 darkness, under objects or in cavities. All are probably solitary 

 spawners as only one male and one female seem to occupy a nest. 



The male fertilizes the eggs and then takes over their care and 

 guarding, probably remaining with them and the young untU the 

 yolk sac is absorbed and the young are able to fend for themselves. 

 The male, especially, is characterized during the breeding season 

 by swollen areas on the head and upper surfaces, and by a drab color. 

 The apparent ripe female seems to be somewhat less differentiated 

 from nonspawning stages. 



Reproduction in Noturus miurus. — Some information was gained 

 on the reproduction and the young of Noturus miurus in the Huron 

 River, 1.7 miles above Dexter, Michigan, in 1951. The river near 

 the shore where the current was slow, had a bottom of silt and mud. 

 In this area were scattered Chara, Potamogeton, and Sagittaria, 

 numerous tin cans, a fallen tree, tree roots, some brush, boards, 

 much debris, and a sunken boat. In the middle of the stream, where 

 the current was somewhat faster, there was submerged vegetation 

 on a bottom of gravel, sand, rubble, marl, and scattered mollusk 

 shells. The water temperature on August 10 was 78°F. 



On August 8 and 10 brooding specimens of Noturus miurus were 

 found here in abundance by picking up the sunken tin cans, a relatively 

 high proportion of which contained two adults or one adult mth 

 young or eggs. Beer cans which had round openings approximately 

 % to 1 inch in diameter were most often inhabited. The inhabited 

 cans were free of detritus and most often had the open end down- 

 stream. They may have been cleaned by the male which guarded 

 the nest. The area was revisited on July 27, 1952, when A^". miurus 

 was again found brooding eggs. 



A sample of 10 nesting individuals, either with eggs or young, was 

 retained. All were males. They ranged in standard length from 51 to 

 71 mm.; four were less than 60 mm. long and five were between 60 and 

 70 mm. Some data were obtained on the relation of size of the male 

 guardian and the number of eggs or young as follows: 55 mm. (34 eggs) ; 

 55.5 mm. (28 young, brood incomplete); 56 mm. (34 young, brood 

 incomplete) ; 64 mm. (35 eggs) ; 67 mm. (38 young, brood incomplete) ; 

 68 mm. (46 eggs). The eggs were large and amber in color. All those in 

 a nest adhered together in an irregular mass until hatched. One guard- 

 ing male swallowed his eggs after placement in a clear glass jar. 



Nest-guarding males were rather characteristic. The black of the 

 saddles and the top of the head had changed to intermediate grayish 



