The nitrogenous excretion rates (total ammonia nitrogen, urea, and primary amines) of plunderfish Harpagifer antarcticus were related significantly to length and to wet mass (mass exponents of 0·94, 1·01, 1·07 and 0·93 for total ammonia nitrogen, urea, primary amines, and total nitrogen, respectively). The routine total ammonia excretion rates [22·23 & 2·0 mg N kg