The Relationship of Bluegill
Sunfish Body Size to Tolerance
for Some Common Chemicals
John Cairns, Jr., Associate Curator of Limnology
and
Arthur Scheier, Department of Limnology
Academy of Natural Sciences of Philadelphia
The purpose of this work was to determine the tolerance of three
distinct size ranges of the blue gill to calcium chloride, potassium
cyanide, sodium nitrate, cresol, sodium carbonate, sodium bicarbonate,
sodium sulfate, zine chloride, ammonium chloride, potassium dichro-
mate, potassium chromate, phenol, sodium hydroxide, and hydrochloric
acid. From these data the relative toxicity of each material tested may
be determined for each size range of fish.
To facilitate accurate comparisons of the tolerance levels of the
different size ranges of fish, environmental conditions were maintained
at constant levels at all times. Periodic tests were made to insure the
maintenance of these conditions.
LITERATURE REVIEW
There is a paucity of literature primarily concerned with effect of
size and weight upon the toxicity of pure chemical substances to fish.
Bastos (1954) working with derris root found that for Astronotus
ocellatus, Cichlosoma bimaculatum, Crenicichla piaba, and Cichla temen-
sis the size and weight of each individual fish has no relation to its
resistance to derris root. In contrast Burdick et al. (1955) working with
six species of temperate zone fishes in various concentrations of emulsi-
fiable rotenone found that there seemed to be a general tendency for the
smaller fish to die upon shorter exposure than was necessary with the
larger fish, and in progressively decreasing concentration the larger
fish were found to be the first to exceed the 24-hour limit of exposure.
Weiss and Botts (1957) found that sunfish exposed to Sarin at different dissolved oxygen concentrations showed an increase in T50 and
oxygen consumption paralleling the rise in dissolved oxygen level; however, the size factor was not strictly proportional among four size
groups in their T50 response in  this particular experiment.   Over a
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