Nitrogen Excretion and Protein Consumption of the Bluegill Sunfish (Lepomis macrochirus)

Nitrogen excretion rates increase with an increase in protein consumption levels. A mathematical description of this relation was formulated from the data. Estimates of the effect of specific dynamic action on nitrogen excretion were also calculated.

Download Full-text

Effects of Temperature and Body Weight on Endogenous Nitrogen Excretion in the Bluegill Sunfish (Lepomis macrochirus)

Journal of the Fisheries Research Board of Canada ◽

10.1139/f69-165 ◽

1969 ◽

Vol 26 (7) ◽

pp. 1813-1821 ◽

Cited By ~ 47

Author(s):

Jan Savitz

Keyword(s):

Body Weight ◽

Lepomis Macrochirus ◽

Nitrogen Excretion ◽

Bluegill Sunfish ◽

Effects Of Temperature ◽

Excretion Rates ◽

Very High

The effects of temperature and body weight on endogenous nitrogen excretion (ENE) rate were examined for fish acclimated at 7.2, 15.6, 23.9, and 29.4–32.2 C. Nitrogen excretion rates were very high at the highest temperature and decreased with a decrease in acclimated temperature from 29.4–32.2 C to 15.6 C. Nitrogen excretion rates were equal at 15.6 and 7.2 C. From these data, an estimate of maintenance protein for a population of bluegidl sunfish (Lepomis macrochirus) was calculated on a seasonal and yearly basis.

Download Full-text

Regeneration of nitrogen and phosphorus by bluegill and gizzard shad: effect of feeding history

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f95-825 ◽

1995 ◽

Vol 52 (11) ◽

pp. 2327-2338 ◽

Cited By ~ 43

Author(s):

Martha E. Mather ◽

Michael J. Vanni ◽

Thomas E. Wissing ◽

Scott A. Davis ◽

Maynard H. Schaus

Keyword(s):

Excretion Rate ◽

Lepomis Macrochirus ◽

N:P Ratio ◽

Nitrogen Excretion ◽

Gizzard Shad ◽

Small Fish ◽

Nitrogen And Phosphorus ◽

Nutrient Excretion ◽

N:P Ratios ◽

Excretion Rates

We combined laboratory and field studies to experimentally assess how the effects of feeding regime and time since feeding influence nitrogen (N), phosphorus (P), and the N:P ratio excreted by two common freshwater fish, bluegill (Lepomis macrochirus) and gizzard shad (Dorosoma cepedianum). In addition, for adult gizzard shad, we modelled excretion rates as a function of the nutrient content of ingested sediment detritus. For both bluegill and gizzard shad, feeding significantly increased nutrient excretion rates and altered excreted N:P ratios. For both species, excretion rates were highest immediately after feeding and declined thereafter. Because the phosphorus excretion rate decreased more rapidly after feeding than did the nitrogen excretion rate, the excreted N:P ratio increased with time since feeding. Young-of-year gizzard shad excreted more nitrogen than adults, resulting in a higher excreted N:P ratio for these small fish. For P, predictions from our model agreed well with our experiments with gizzard shad; for N, the agreement was not as strong yet was still reasonable. In summary, N:P ratios excreted by these fish differed across species, size, and time since feeding. Variation in these factors may explain discrepancies among studies that examine both trophic interactions and nutrient budgets.

Download Full-text