THE AGAR] UM: 

CONDUCTED BY HUGO MULERTT. 
[The Editor of this Department will cheerfully answer all queries relative to the conduct of Aquaria. } 
THE NEST-BUILDING STICKLEBACK. 
Sticklebacks are wonderful fish and with 
hem many wonderful things are possible. We 
know of no other fish that harmonize their col- 
ors to the surroundings as do the sticklebacks. 
Take the many-spined stickleback as an exam- 
ple. Ina pond at Maspetto, L. I., which hasa 
bottom of white clay, and was so situated as 
to be under the full glare of sunlight nearly ail 
day, the color of the sticklebacks was that of a 
dirty white. A 
harmony with the surroundings. This is a. 
wise precaution for masking the contents of the: 
nest from other fish, particularly the stickle-. 
backs, who are very fond of fish eggs. 
The following description by one of our 
friends will assist you when about to establish. 
a ‘‘sticklebackery ” without being in possession 
of a regular aquarium tank: 
“Up in the hay loft was a box of window 
glass. Taking a number of panes ot giass, I 
formed in a wash- 



half mile beyond 
tub a series of 


















this pond was a 



compartments in 







ditch containing 



peaty water; here 

the following 
manner: From 







the same variety 




of — sticklebacks 
were brown. A 
few yards beyond 
this ditch was a 
hole, the bottom 
















the centre of the 
tub the panes of 
glass radiated un- 
til they came in 
close contact with 
the sides of the- 










of which was? 
tub, thus forming 



black creek mud ; 
a series of acute- 

here the stickle- 
backs were jet 
black, even to the 
eyes. The male 
fish of the two-spined species, Gasterosteus 
aculeatus (see illustration), are more wonder- 
still, as illustration of this fact. The first indi- 
cation that a male stickleback is about to con- 
struct a nest is the taking on of green and red 
colors, the eye at the same time becoming 
blue. When the nest is completed, and the 
time has come to either coax or drive the fe- 
male to deposit her ova in the nest, then the 
colors of the male become wonderfully intense, 
the red on the lower part of his body becoming 
almost luminous. These colors the male re- 
tains until he abandons the young sticklebacks 
to shift for themselves. 
In nature the male stickleback always selects 
material for his nest that is in keeping and 

angles; the bot- 
tom edges of the- 
glass were then 
crowded down 
through the three inches of sand till they rested 
on the bottom of the tub. In the apexes of the- 
angles bunches of water: plants were planted ; 
this also helped to sustain the glass compart- 
ments, as well as to keep up thorough oxygen-- 
ation of the water. In each compartment I 
placed a pair of sticklebacks, giving them a 
meal of angle worms before leaving them for 
the night. Next morning when I examined 
the tub, to my great surprise many nests had 
been made during the night. In some of them 
the bright yellow eggs showed plainly through 
the openings of the nest. Every nest was vig-- 
orously ventilated by the male fish, who were 
hard at work fanning a current of water on. 
them with their pectoral fins. In one compart 
