Nitrogen excretion and changes of hemocyanin, protein and free amino acid levels in the hemolymph of Penaeus monodon exposed to different concentrations of ambient ammonia-N at different salinity levels

Abstract

ABSTRACT. Penaeus monodon (22.064 * 2.263 g) were exposed individually at 10, 20 and 30% salinity to 0 (control), 1, 5, 10 and 20 mg 1-' ammonia-N for 24 h. Changes in hemocyanin, protein and free amino acid levels, and whole shrimp ammonia-N excretion, urea-N excretion and dissolved organic N (DON) excretion were determined. Ammonia-N excretion decreased with increased salinity and with increased ambient ammonia-N. Ammonia-N accounted for 56.87. 70.43 and 78.13 % of total nitrogen excreted by P. monodon in 30, 20 and 10% respectively. DON increased to 67.26, 78.79 and 86.1% of total nitrogen excreted by the shrimp exposed to 20 mg 1-' ammonia-N in 30, 20 and 10°A, respectively. Net ammonia-N uptake occurred as shrimp were exposed to ambient ammonia-N greater than 5 mg 1-I at all salinity levels tested. Hemocyanin and protein levels decreased, whereas hemolyrnph ammonia, urea, total free amino acid levels and taurine level increased, with increased ambient ammonia-N. Following exposure to ambient ammonia-N, P. rnonodon changed its excretory pattern, accumulation of hemolymph ammonia, and catabolism of hemocyanin and protein to balance osmoregulation.

Fluxes of haemolymph ammonia and free amino acids in Mytilus edulis exposed to ammonia

“…These studies show that the ammonia-N excretion of M. edulis increased directly with ambient ammonia concentration over the range 0 to 20 pM NH4-N. Similar results were found by Chen et al (1994) for Penaeus monodon. At ambient concentrations >l00 pM, a net ammonia uptake occurred after 1 h of exposure and during the following 1 h of treatment.…”

“…These data suggest an altered metabolism of the mussel and may indicate the production of FAA as a shock response, or may also indicate an altered pro- tein synthesis. Such conclusions were also drawn by Chen et al (1994) on the basis of his data relating to Penaeus sp. Although Mytilus edulis was found to withstand high ammonia levels, its ability to cope with a simultaneous, in situ oxygen deficiency (due to eutrophication) and a relatively high dissolved ammonia concentration still needs to be investigated, as hypoxia and ammonia enrichment were found to increase total amino acid levels in the body, the consequences of which are unknown.…”

Hemolymph ammonia and urea and nitrogenous excretions of Scylla serrata at different temperature and salinity levels

“…3 semisulcatus at 40.5%0, and to account for 57, 2 and 22 % of total nitrogen excreted for Penaeusmonodon at 30%0 (Wajsbrot et al 1989, Chen et al 1994. In the present study, higher urea-N excretion with a concomitant higher hemolymph urea-N at 40%0 suggests that urea is formed.…”

“…In crustaceans, nitrogenous excretion is affected by both extrinsic factors, such as temperature and salinity, Table 2. Scylla serrata The percentage of ammonia-N excretion (ANE), urea-N excretion (UNE), nltrite-N excretlon (NINE), nitrate-N excretion (NANE), and organic-N excretlon (ONE] from nltrogenous excretlons of crabs maintained at dlfferent salinit~es (S) and temperatures (T) and intrinsic factors, such as molt cycle, nutritional level and neuroendrocrine control (Regnault 1987, Chen et al 1994. Since the crabs used in the present study were at the intermolt stage and had been fasted for 1 d , they were considered to be at the same nutritional level.…”

Physiological responses and scope for growth of Ruditapes decussatus from Ria Formosa, southern Portugal, exposed to increased ambient ammonia

“…En este trabajo se aborda la sensibilidad de los estudios en energética fisiología y la necesidad de estudios en tolerancia de bivalvos de la infauna para definir respuestas indicadoras que permitan comprender las condiciones de crecimiento y de reproducción en poblaciones estresadas. excretion of ammonia (Schmitt and Uglow, 1997;Chen and Chen, 1997) and the combined effects of ammonia and salinity (Chen et al, 1994;Lin and Chen, 2001). Sadok et al (1995) examined the tolerance of the mussel Mytilus edulis to ambient ammonia.…”