Biological Survey — Erie-Niagara Watershed 181 



Table 1.— Species Feeding on Algae and Fragments of Higher Plants 



name 



Margariscus m. mnrgaritn 

 (Pearl minnow) 



Notropis cornutus. 

 (Reid-fin shiner) 



A'', c. frontalis , 



(Common shiner) 



N. c. chrysocephalus. . . 

 (Common shiner) 



H yborhynchus notatus. . 

 (Blunt-nosed minnow 



NT umber 



of 

 records 



Pimephales promdas . . . 



(Fat-head minnow) 

 N otemigonus crysoleucai 



(Golden shiner) 



Campostoma an omnium . 

 (Stone-roller minnow) 



10 



33 



Lengths 



21 



16 



Cm. 



3.7-4.8. 



4-9.8. 



Inches 



4.3-7.7.. 



3.2-.5.8. 



5-12. 



1.6-2... 

 2.6-6... 



n. 



11-31 



U-21 



U, 



U-3 



Silt 



Food materials 



10' 



10% 



40% 

 30% 



40% 



40% 

 8% 



35% 



Misc. algae, 90% : Spirogyra, 

 Ulothrix, Oedogonium, 

 Characium, Gomphonema, 

 Scenedesmus, Cosmarium, 

 Navicula, Cymbella, Sy- 

 nedra, Oscillatoria 



Plants, bO%: plant frag- 

 ments, Spirogyra, Oedo- 

 gonium, Ulothrix, Clado- 

 phora, Cosmarium, Clo- 

 sterium, diatoms; fish eggs, 

 adult insects and earth- 

 worms, 30% 



Oscillatoria, 30%; diatoms, 

 5% ; plant fragments, 25% 



Diatoms, mainly Synedra 

 and Navicula, 70% 



Fish eggs, 15%; algae, 45%; 

 Pediastrum, Cosmarium, 

 Closterium, Scenedesmus, 

 Spirogyra, Oedogonium, 

 Cladophora, Oscillatoria, 

 Navicula, Synedra, En- 

 cyonema, Gomphonema, 

 Cymatopleura, Pleuro- 

 sigma 



Misc. algae, 60% 



Snails, 8%; Cyclops, Ostra- 

 coda, Leydigia qaudrangu- 

 laris, 7%; adult midges, 

 12%; Triaenodes larvae, 

 8%; algae, 53%: Oscilla- 

 toria, Ulothrix, Navicula, 

 ^lerismopaedium 



Chironomus larvae, 90%; 

 diatoms, 10% 



Difflugia, Anurea cochlearis, 

 25%; misc. algae, 40%: 

 Scenedesmus abundans, S. 

 bijuga, S. arcuatus, S. 

 dimorphus, Spirogyra' 



Ulothrix, Oedogonium, 

 cosmarium cyclicum, Phor- 

 midium, Synedra, Encyo- 

 nema, Pediastrum, ]Meri- 

 smopaedium tenuissimum, 

 Staurastrum alternans, 

 Navicula, Meridion 



Species Feeding Mainly upon Immature Aquatic Insects 

 and Crustacea. — Thirty-four of the 64 species studied come 

 under the above headino^. In this area the forms which are found 

 most commonly in stomachs are the larvae and pupae of the midges 

 (Chironomidae). These are taken by all of the species in this 

 group. The percentages are usually high. Among the suckers, 

 for example, the averages range from 50 to 80 per cent.^ 



For a summary of the food of members of this group, see Table 3 on p. 186. 



