72 U. S. BUREAU OF FISHERIES. 
In addition to the hatchery exhibit a display of adult fresh-water 
fishes was maintained in the aquaria throughout the year. The 
total number of fish exhibited was 2,614, representing 45 species. 
Collections for restocking were made from time to time from the 
Potomac River at Bryans Point, Md. Other sources of supply were 
the bureau’s stations at White Sulphur Springs, W. Va.; Bellevue, 
Towa; Bozeman, Mont.; the New York Aquarium, and the New 
York Conservation Commission hatchery at Caledonia, N. Y. 
The health of the aquaria fishes throughout the year was gener- 
ally good, with the exception of a short period during May and 
June, when a number of the fish were attacked by the parasite 
Ichthyophthirius, causing a considerable loss, particularly among 
the warm-water fishes. It has recently been found that this para- 
site may be destroyed by treating the fishes infected with a saturated 
solution of bicarbonate of soda. The solution is conveniently ap- 
plied directly to the fish when held in shallow water with a small 
paintbrush. The treatment removes the mucous coating from the 
fish and destroys the parasite with no injury to the fish. 
Spawning Seasons of Fishes Handled at Stations. 
Records of the spawning seasons of the various species of fishes 
handled at the bureau’s stations during the fiscal year 1921, together 
with the water temperatures at the beginning and end of such pe- 
riods, are given in the following table, in which the stations are 
grouped and arranged as in the preceding discussion of the propa- 
gations of the commercial species and the species for stocking the 
interior waters; that is, Pacific salmon, Great Lakes, Marine, New 
England salmon and trout, Rocky Mountain trout, combination 
trout and pond fish-cultural, and pond fish-cultural stations. 
SPAWNING SEASONS OF FISHES HANDLED AT STATIONS, WITH WATER TEMPERA- 
TURES AT BEGINNING AND END OF PERIODS, FIscaL YEAR 1921: 
PACIFIC SALMON STATIONS. 
Water tempera- 
tures, °F. 
Station. Species. Spawning season. 5 
eae End of 
season. | Season. 
Afognak, Alaska..........- Sockeye salmon....:-..--- July 31 to Sept. 24......... 52 40 
Baker Lake, Wash........- Silver salmon-...........-- Nov. 17 to Dec. 15........-. 40.5 35.5 
Sockeye salmon.........-.- Oct. 10 to Nov. 30-t --.-.-: 46 39 
BirdSview-.--cocscee eee Chinook salmon......----- Sept. 20 to Oct. 25. ....... 43 41 
Silver'salmon:). 2. <<. 5%. - Nov. 20 to Feb. 11-.......- 43 41 
Steelhead salmon...-......- Mar. 26 to May 21........- t4 47 
Brinnon se -s fee epee Chum Salmon-2--. 2 7. 4 Nov. 15 to Jane6:-25.2.._- 50 48 
Steelhead salmon......... Apr 15 to May Idiom t. 6.2 42 52 
Duckabush-se-:2 3. 3.-= Chum salmon o.- 2 -<s.-. Aug. 28 to Sept. 12........ 49 49 
Silver salmon. .-.....--:.-- Nov. 27 to Mar. desseseae 46 44 
Steelhead salmon..-......-- Acpr,. Lito Mia yi 27. des oe 46 48 
Quileence!s64 2 eee Chum salmon, early..-..-- AUg.123 tolOCt..62..22 2243 51 50 
Chum, salmon, late......-- Nove4 tO anitoe. sete ene 45 45 
Silver salmon. ..-- ..| Oct. 20 to Jan. 20. 47 43 
Steelhead salmon ..| Mar. 22 to June 1. 45 49 
Quinsolte=e- eee Chinook salmon. =| Oct. L touNOve Lon. - 47 40 
Silver salmon. .- -| Nov. 3 to Dec. 15... 42 40 
Sockeye salmon. aie Sie GO sta teee tee cee 42 40 
Sultan -.\.55- So en sere sot Chinook salmon. ene sD beeke LOO Ciel Ose eee ane 51 47 
Silver salmon..-........-- Oct. 8 to Feb.2...-.-2-..- 49 42 
Steelhead salmon.... -....1 Mar. 10 to May 28........- “42 45 
