Vol. XX. March, 1911. No. 4. 



BIOLOGICAL BULLETIN 



THE NESTS AND LARV^: OF NECTURUS. 



BERTRAM G. SMITH. 



THE NESTS. 



I. Nests in a Lake Habitat. Through the courtesy of Professor 

 Bennet M. Allen I recently became acquainted with the spawning 

 grounds of Necturus maculosus Rafinesque in Lake Monona, Wis. 

 During the latter part of June and the early part of July, 1910, 

 several trips were made to the locality for the purpose of ob- 

 taining embryological material. 



The "nests" were found in water about 3-5 feet deep and 

 about 50-100 feet from the shore, in a locality where the bottom 

 was strewn with loose flat stones of various sizes. The largest 

 of these stones, about 1^-2 feet in diameter, frequently served as 

 cover for the eggs of Necturus. The eggs are attached by the 

 slender stalks of the gelatinous envelopes singly to the under 

 sides of these stones, distributed over an area about 8-IO 

 inches in diameter (see Fig. i). The presence of minute algse, 

 etc., in the water made it so opaque that it was impossible to 

 see the bottom; the eggs were obtained by wading in the water, 

 feeling about with the feet for a large flat stone, then bringing 

 it to the surface. 



Eycleshymer ('06) describes nests of eggs attached to the 

 under sides of logs, boards, pieces of tin, canvas, etc., but does 

 not mention finding nests under stones. Doubtless any con- 

 venient object may be selected as cover. 



The number of eggs present in a nest was determined in five 

 cases as follows: 18, 61, 80, 84, 87. The average is 66. The 

 nest photographed contained 84 eggs. 



The first embryos were obtained on June 22; these were in 



an advanced stage of development, with head well formed and a 



191 



