Variation in nitrogenous compounds and gonad index in fed and starved sea urchins (Paracentrotus lividus) during live storage

Initial mean values of ammonia and nitrate excretion of 46.03 ± 4.28 5 mol NH4-N individual− 1 h− 1 and 0.45 ± 0.04 mg NO3 individual− 1 h− 1, respectively, dropped to 2.55 ± 0.33 NH4-N μmol individual− 1 h− 1 and 0.1 ± 0.02 mg NO3 individual− 1 h− 1 after 5 days (p < 0.05; one-way ANOVA in each case). Concomitantly, free amino acid concentrations dropped in the gonads and the coelomic fluid. Coelomic fluid TMA concentrations were constant throughout all the conditioning period; however, an increase of the gonad TMA level occurred after 5 days to reach a mean of 0.37 ± 0.02 μmol TMA g− 1 and then remained stable to the end of the experiment (36 days).