Biological Survey — Erie-Niagara Watershed 95 



depth 4.3 mm; diameter of eye 1.5 mm. Mouth very large, oblique, 

 lower jaw projecting, maxillary ending about middle of pupil. 

 Pigmentation essentially as in younger stages, sides of body being 

 closely covered with stellate and round chromatophores of vanang 

 sizes; 3 longitudinal rows on either side of dorsal ridge, and 

 single line either side of ventral ridge behind vent; peritoneum 

 black; head less pigmented than body, and underside of stomach 

 much lighter than rest of body; fins colorless. 



7. — Seining Eecords and Food of the Intermediate Stages of Lake 



Erie Fishes 

 By a. E. Allin 



Although the biological part of the summer's work consisted 

 largely of plankton analyses and a study of the early life history 

 of the fishes of Lake Erie, due record was made of any later stages 

 observed or taken in the nets. Occasionally a larger specimen 

 was taken in the meter net or the Helgoland trawl, but sucli occur- 

 rences were uncommon. Such gear rarely captures any fishes 

 longer than 25 mm. in the daytime due to the limited straining 

 ability of the fine mesh. For stages between 25 mm. and 60 mm. 

 offshore the Petersen trawl has proven most effective, and is quite 

 as applicable to large lakes as to the sea. 



The efficiency of the net is indicated by the catches of 631 and 

 212 specimens respectively taken at stations 2 and 4 on the second 

 trip. In view of the small number of specimens obtained at most 

 of the other stations it would appear that there were few fishes 

 between the lengths of 25 and 60 mm. offshore during the period 

 of the investigation. The yearlings of the fall spawners (of 1927) 

 were too large and active to be taken, and many, perhaps the 

 majority of the early spring spawners, would most likely have 

 been found in the shallower waters about the margin of the lake. 

 The young of those species spawning in the early summer were 

 taken in the fine mesh nets. It may be noted that the greater 

 number of intermediate stages was found at the eastern end of 

 the area studied. 



On July 9, 1928 three hauls were made at the mouth of a small 

 stream on the west side of Grand Island with a one hundred 

 fifty foot seine for the purpose of determining what food was 

 being taken by the fish of the region. The natural lake food supply 

 was supplemented by outwash from the land as well as backwash 

 from the Niagara river. 



Although the number is too small to give an adequate idea of 

 the food of the fish in the lake, excepting at one or two individual 

 stations, it is interesting to observe that those fish, taken in the 

 seine hauls, vividly show a balance of nature even in so restricted 

 an area. There are those fish feeding on algae and diatoms, those 

 living practically on crustaceans or larvae of aquatic insects, and 

 finally those feeding on smaller fish and fish eggs. In the first class 

 may be included the Cyprinidae and Catostomidae ; in the second, 

 the smaller Percidae and Centrarchidae ; in the third, the larger 

 Percidae, Esocidae, and Catostomidae (fish eggs). 



