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BODY NITROGEN AND NITROGENOUS EXCRETION IN NEOMYSIS RAYII MURDOCH AND EUPHAUSIA PACIFICA HANSEN 1
Author(s) -
Jawed Mohammad
Publication year - 1969
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1969.14.5.0748
Subject(s) - euphausia , excretion , urea , nitrogen , chemistry , excretory system , amino acid , ammonia , zoology , biology , biochemistry , endocrinology , ecology , crustacean , organic chemistry
The rates of nitrogenous excretion in the form of ammonia, amino acids, urea, and total nitrogen are determined for Neomysis rayii and Euphausia pacifica at two temperatures, 10 and 4C. Temperature has a marked effect on the excretory rates. Ammonia‐N is the dominant form of excretion in both species (72–87% of nitrogen excreted), and the amounts of amino nitrogen excreted by both organisms are much lower than reported by earlier authors for other zooplankton. There is evidence that amino‐N is excreted below 6C. Small quantities of urea are excreted by Euphausia pacifica only. Neomysis rayii excretes 25 µ g N/mg body nitrogen per day at 10C and 15 µ g N/mg body nitrogen per day at 4C. Euphausia pacifica excretes 21 µ g N/mg body nitrogen per day at 10C and 12 µ g at 4C. While starved, these species catabolize proteins almost exclusively and lose about 2% of body protein per day.