TECHNIQUES OF FISHPOND MANAGEMENT 5 
erals held in solution by the water, the phytoplankton is the basic 
organic resource of the water and upon it depends the life of all ani- 
mals in the pond. 
The zooplankton consists primarily of protozoans, rotifers, and 
crustaceans. Most of these animals feed upon microscopic plants or 
phytoplankton; some are carnivorous and feed on other minute ani- 
mals. The crustaceans are the largest animals in the zooplankton 
end include the cladocerans, copepods, and ostracods. They are an 
important source of food for insect larvae and young fish. 
Although phytoplankton is the basic food in a pond, few fish feed 
directly upon it. The goldfish (Carassius auratus) and the golden 
shiner (Votemigonus crysoleucas) feed primarily on plankton organ- 
isms, but most pan and sport fish feed on either insects or other fish. 
The bluegill bream (Lepomis machrochirus) and the bullhead 
(Ameturus natalis) are largely isectivorous. The large-mouth 
black bass (Huro salmozdes) and the white crappie (Pomoais annu- 
laris) are primarily carnivorous and feed on any fish smaller than 
themselves. The very young of bluegill bream and of large-mouth 
black bass feed upon the zooplankton. Soon, though, they start feed- 
ing on insect larvae and from that time on, insect larvae are the 
primary food of the bluegill (table 1). The young bass, however, 
quickly change to a diet of fish, and when weighing 2 ounces they eat 
the same type of food as do bass weighing 2 pounds (table 1). Both 
bluegill bream and large-mouth black bass are predaceous—they feed 
upon animals and take plants only when there is insufficient animal 
food (6). Aquatic insects, therefore, are the link between plankton 
and fish. 
TasLe 1.—Food taken from stomachs of bluegill bream and large-mouth black 
bass* from ponds in various sections of Alabama (6) 
Stomachs in 
which item stomachs 
Kind of fish Food item was first in tt NKATEEE 
relative vol- | tei 0c- 
ae curred 
Percent Percent 
AWWia. Gerri GCS etn teeeaceeneer en eet Seo Seek oe Ome .4 
Miphailyamhyamyolng oe ee ee 6.6 | fale 
Dracontiyaniyimp ish sass sete we we ee Wea 33.3 
MamSelethyeniyin See ees oe eee ome 0 22 
Wiaiterboa tind Greet sense eteee eee eee 0 6.6 
Wid CORSET: C CTS ie seem erence Loe ee Dts 4.4 
RATHI GEC etles sasmacte eee ne ae eee 0 Deo 
Bluegill: bream === = (OByaWGhisn nO ans 258 ee ye a 13.3 33.3 
Phantomunidgevlarvacs 2 ta ee 929) anal 
IVR OLaGhy IBID Ee 0 252 
VIM Glo kee JEP AYO Se eee ee 35. 5 ileal 
Ceratopozonidvlanvacs === kee 6.6 Set 
IMIG ROXORURLENCESY = 5 es ee 6.6 3h. 1 
WEN S ett seer Sart are eae AREAS ae Sadie 4.4 fet 
IPMENa TOMER Ss 2 4.4 1555 
Dracontlygnyan p hs sees eee eee oe 20. 0 33.3 
Wiatenbo atime mass is ae ee ee 0) 18% 83 
Wiaterstri ders = see. a= sae See et eee ee Ee os 0 6.6 
Large-mouth black bass_________ Wind serlanvaceie— nike aaa ae eee a 0 20. 0 
S Fray Sener ees ees ye es Baa nye ene 0 6:6 
| IMDOROKC RE IBCE a= ek eee eh 0 6.6 
I WESIS 1g eee ius Bete VE Shot Te Nea Oe ES 80. 0 86.6 
1 Bream weighed 1 ounce or more and bass 2 ounces or more. 
The insects commonly found in water are from the groups repre- 
sented by stor flies, Mayfftes, dragonflies, dobson flies, caddisflies, 
