274 BULLETIN OF THE BUREAU OP FISHERIES. 



Salmo irideus (Jordan and Evermann). Rainbow trout. 



Station 30; August 26, 1915; number examined, i. Length: 126.5. Food: Chironomus fulvi- 

 ventris larvse, 5; Tanypus decoloratus larvae, 5; Psychoda larvse, 5; Phryganea larvae, 8; Odontomyia 

 larvae, 10; Chironomus fulviventris pupae, i; C. lobiferus pupae, 2; leptid adult, 4; Peltodytes 12-puncti- 

 pennis adult, 3; Julus, 10; Gammarus limnaeus, 42; Physa, 5. 



Summary. — Food: Insect larvae, 33; pupae, 3; adult insects, 7; millipeds, 10; amphipods, 42; snails, 5. 



Salvelinus fontinalis (Mitchill.) Brook trout. 



Station 30; August 26, 1915; number examined, 18. Length: Maximum, 160; minimum, 87; average, 

 103.2. Food: Dipterous larvae, 3.5; Chironomus fulviventris larvae, 13.2; Tanypus decoloratus larvae, i; 

 Psychoda larvae, 0.3; Phryganea larvae, 11. 5; Agabus larvae, 1.8; Odontomyia larva, i.i; Dytiscus hybri- 

 dus larvae, 0.5; Dixa larvae, i; Chironomus fulviventris pupae, 18.2; C. lobiferus pupae, 0.2; leptid flies, 

 0.8; Peltodytes 12-punctipennis adult, 0.2; Agabus adult, i.i; Corixa adults, 0.3; Camponotus adult, 

 o.i; Melanoplus femurrubrum adult, 3; jassid bug, o.i; Julus, 0.4; Limnesia histrionica, 0.4; Gammarus 

 limnaeus, 35.5; Asellus communis, 0.5; Procellio rathkei, 0.8; Physa, 1.4; seeds, +; Polygonium seeds, 



O.I. 



Summary. — Food: Insect larvae, 33.9; pupae, 18.4; adult insects, 5.6; millipeds, 0.4; mites, 0.4; 

 amphipods, 35.5; aquatic isopods, 0.5; terrestrial isopods, 0.8; snails, 1.4; plant seeds, 0.1. 



This trout feeds largely on insects and other arthropods. The Fish Manual (1900) has this state- 

 ment: "The brook trout has a voracious appetite and takes advantage of every opportunity to satisfy 

 it, except in the spawning season, when it takes no food at all. It is strictly a carnivorous fish, its 

 food consisting chiefly of Crustacea, mollusca, and various forms of insects and worms. When pressed 

 with hunger, it does not hesitate to devour its own kind." Tracy (1910) said this fish will eat nearly 

 any small living creatine — insects, fish, its own eggs and young, tadpoles, newts, etc. 

 Schilbeodes gyrinus. (Mitchill.) Tadpole cat. 



Data for IQ14 (Pearse, 1915). — Station 4; August 6; number examined, 5. Length: Maximum, 26.8; 

 minimum, 17.6; average, 22.3. Food: Insect larvae, 8; adult insects, 4; Hyalella, 0.4; ostracods, 0.4; 

 copepods, 62; cladocerans, 1.6; algae, 4.2; silt and debris, 15. 



Station 5; May 12; number examined, 14. Length: Maximum, 76; minimum, 30.3; average, 42.8. 

 Food: Insect larvae, 1.4; chironomid larvae, 2; Chironomus lobiferus larvae, 7; C. fulviventris larvae, 1.8; 

 Pelopia monilis larvae, 3; Orthocladius soldidellus larvae, 2 ; May -fly nymphs, 12; Baetis pygmaea nymphs, 

 10; Callibatis nymphs, 10; Corixa nymphs, 1.3; Neiu-onia postica pupK, 2.4; Chironomus lobiferus 

 pupa, 2; grasshopper, 1.4; Enallagma antennatum adults, 5; adult dipteron, 2; Hyallella, 7; ostracods, 

 6.5; Cyclops, 2 ; chydorus sphaericus, 11 ; Simocephalus, 0.5; Eurycercus lamellatus, 6.3; oligochates, 1.4; 

 fine debris, 2. 



Summary. — Food: Insect nymphs and larvae, 50.5; pupae, 4.4; adult insects, 8.4; amphipods, 7; 

 ostracods, 6.5; copepods, 2; cladocerans, 17.8; oligochaetes, 1.4; debris, 2. 



Station 5; June i; number examined, 9. Length: Maximum, 45; minimum, 38.5; average, 42.6. 

 Food: Chironomus lobiferus larvae, 4; Orthocladius sordidellus larvae, 16; damsel-fly nymphs, i.i; beetle 

 larvae, 33.2; Naucoris nymphs, 8.3; Chironomus lobiferus pupae, 2.7; C. decorus pupae, 7.2; Odontomyia 

 pupae, 0.5; Lachnostema adult, 1.9; ostracods, 8.5; Cyclops, 9; oligochiEtes, 5.5; filamentous alga;, 0.1; 

 fine debris, 2. 



Summary. — Food: Insect larvae, 62.6; pupae, 10.4; adult insects, i.g; ostracods, 8.5; copepods, 9; 

 oligochaetes, 5.5; filamentous algae, 0.1; fine debris, 2. 



Station 5; August 9; number examined, 2. Lengths: 21.5, 21. Food: Protenthes culiciformis larvae, 

 15; Callibaetis nymphs, 17.5; mite, i; Hyalella, 12.5; ostracods, i; Chydorus sphaericus, 0.5; Campto- 

 cercus, 17.5; oligochaetes, 12.5; seeds, 17.5; fine debris, 5. 



Summary. — Food: Insect larvae, 32.5; mites, i; amphipods, 12.5; ostracods, i; cladocerans, 18; 

 oligochaetes, 12.5; seeds, 17.5; debris, 5. 



Near Station 5, on lake shore; August 18; number examined, 14. Length: Maximum, 63; minimum, 

 14; average, 25.8. Food: Chironomus lobifeius larvae, 1.4; damsel-fly nymphs, 1.4; May-fly nymphs 

 0.7; Ecdyurus maculipennis nymphs, 1.3; Caenis diminuta nymphs, 27.7; Hyalella, 6.7; ostracods, i, 

 Camptocercus, 0.2; cladocerans, 0.2; Planorbis, 0.3; oligochaetes, 42.7; seeds, 15; duckweed, 1.4. 



Summary. — Food: Insect larvae, 32.5; amphipods, 6.7; ostracods, i; cladocerans, 0.4; snails, 0.3; 

 oligochaetes, 42.7; plants, 16.4. 



