SIXTY-TWO SPECIES OF FISHES FROM LAKE ERIE 
317 
behind vent, 2.5; diameter of eye, 1.5; length to dorsal, 9.0; length to anal, 13.5 
millimeters. Myomeres, 25 to vent plus 12+ behind. Dorsal I (very weak), 27; 
anal I (very weak), 7; ventrals 10, short; caudal forked; pectorals short, low. The 
falcate dorsal fin well formed, but its anterior rays are not as greatly produced as 
in the adult. Body oblong, with ventral outline nearly straight and dorsal slightly 
arched; mouth inferior, small, and horizontal; snout beginning to be pointed at this 
stage. Air bladder two-chambered. 
Pigmentation. — Chromatophores are sparsely distributed on upper jaw, sides 
and top of head, more numerous over brain region and dorso-lateral aspects of body. 
A single row of larger spots lies along the dorsal ridge to caudal. Below lateral line 
chromatophores are scattered more widely. Double series on either side of anal 
fin is continued to caudal (unfortunately not well shown in specimen, fig. 22). Dorsal 
and caudal are well marked with pigment, but other fins have few chromatophores 
or none. 
Family CATOSTOMID^, Suckers 
7. Catostomus commersonii (Lacep&de). Common sucker; white sucker; mullet. 
RECORD OF CAPTURE 
Numerous young, 15 to 25 millimeters long, were taken abundantly in shallow 
water at the eastern end of Lake Erie by meter nets, dip nets, and seines from the 
middle of June to the middle of July, 1928. None was taken by the Shearwater in 
1929, probably because less work was done far inshore during this period. This 
species is one of the most common and widely distributed in the Lake. 
DESCRIPTION 
The very long intestine (myomeres, 33 to vent plus 10 behind) differentiates the 
young suckers at all stages from other species taken by the survey. 
Egg . — The unfertilized egg measures 2.5 to 2.82 millimeters in diameter, being 
round, white, without oil globules, and finely granulate in texture. After fertilization, 
which occurs a few moments after .extrusion, the egg measures 3 millimeters and the 
vitellus 2.5 millimeters. 
The embryology and development have been thoroughly reported upon by N. H. 
Stewart (1926). It will suffice here to record the measurements and descriptions 
of two stages during the period of greatest change. 
