Date of Award

Spring 1977

Document Type


Degree Name

Master of Science (MS)


Ocean & Earth Sciences



Committee Director

Anthony J. Provenzano

Committee Member

Chester E. Grosch

Committee Member

Daniel M. Dauer

Committee Member

Paul A. Haefner

Call Number for Print

Special Collections LD4331.O35 H56


The effects of nitrite and nitrate on survival and larval development of the grass shrimp Palaemonetes pugio were investigated in the laboratory. Nitrite concentrations assayed were 0 (control), 0.5, 1.0, 10, 25 and 50 mg NO2/1. Nitrate concentrations tested were 0 (control), 100, 250, 500, 1000 and 2000 mg NO3/1. Temperature and salinity conditions were 25 C and 25 ‰, respectively, and all tests occurred in the dark. Thirty-six larvae were reared in each assay, twelve from each of three adult females.

Nitrite levels of'5 and 50 mg NO2/1 significantly reduced survival of larvae (1% level). No larvae survived to metamorphosis in 50 mg NO2/1. Sublethal effects of ≥10 mg NO2/1 included extended development time, increased numbers of larval stages, reduced sizes of postlarvae and morphological deformities.

The levels of nitrate tested caused no significant (5% level) variations in mortality, numbers of larval stages or sizes of postlarvae. However, nitrate produced slightly extended duration of development (1% level of significance). Based on the evidence gathered in this report, nitrate may be several orders of magnitude less toxic to P. pugio than nitrite.


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