Stress and metabolic indicators in a relatively high (European sea bass,Dicentrarchus labrax) and a low (meagre,Argyrosomus regius) cortisol responsive species, in different water temperatures

Abstract

The aim of this study was to examine species‐specific differences in pre‐ and post‐stress concentrations of haematological, metabolic and hormonal parameters in two Mediterranean fish species, one with relatively high (European sea bass, Dicentrarchus labrax) and the other with low (meagre, Argyrosomus regius) basal and post‐stress blood cortisol concentrations, in relation to different water temperatures. Fish were reared in net‐pen sea cages and exposed to an identical acute stressor (crowding and chasing with a net for 5 min) in three different periods of the year. Results indicated that inter‐specific differences occurred in most of the examined parameters. In addition, within each species, differences between sampling periods existed in plasma cortisol, glucose, osmolarity, blood pH and muscle glycogen concentration. Glucose, lactate and osmotic pressure showed a constant pattern of change, with maxima at half an hour post stress in both species, while cortisol, and blood and muscle pH, were significantly altered only in E. sea bass. No alterations were observed in liver and muscle glycogen concentrations in E. sea bass, while a significant reduction was evident only in the coldest temperature in meagre. It is concluded that there are important species‐specific differences in the magnitude of hormonal and metabolic response to acute stress and that both basal and post‐stress blood cortisol concentrations are affected by the sampling period.

Effects of salinity level on the survival, growth, feed utilization, carcass composition, haematological and serum biochemical changes of juvenile Meagre (Argyrosomus regius) (Asso, 1801) grown in ground saltwater

“…The modulation of haematological parameters may be an indicator of inappropriate environmental conditions or the presence of stress factors (Barcellos et al, ). The recorded values of haemoglobin (Hgb) in the present study were similar to the obtained ones by Samaras, Papandroulakis, Costari, and Pavlidis, () for meagre, whom found slightly lower concentrations (3.5–5.7 g/dl) in A. regius than in seabass, Dicentrarchus labrax (7.7–9.3 g/dl). Additionally, other researchers found the same trend for other marine euryhaline species such as the dusky kob, Argyrosomus japonicus (Woolley, ).…”

Comparing Immobilization, Recovery, and Stress Indicators Associated with Electric Fish Handling Gloves and a Portable Electrosedation System

“…); maximum levels are detected 30 min after application of an acute stressor (Samaras et al. ). Stressed fish enduring extensive anaerobic metabolism accumulate lactate in their blood plasma (Raby et al.…”

“…Lactate, which is associated with the secondary stress response, is produced in an effort to satisfy increased demands for energy and oxygen ; maximum levels are detected 30 min after application of an acute stressor (Samaras et al 2016). Stressed fish enduring extensive anaerobic metabolism accumulate lactate in their blood plasma (Raby et al 2013) as a byproduct of producing energy in the absence of oxygen .…”

Effects of the Dietary Tryptophan and Aspartate on the Immune Response of Meagre (Argyrosomus regius) after Stress

“…Feed homogenization was done through basic hydrolysis as reported in [37]. For derivatization, an aliquot (100 µL) of standard solution or sample was placed in a 2-mL vial, adding 400 µL of a water/ethanol/pyridine (60:32:8) mixtureand 40 µL of Fishes 2018, 3, 6 9 of 13 ethyl chloroformate.…”

“…Identification of derived amino acids was achieved comparing the gas chromatograph retention times and mass spectra with those of the pure standard compounds. All mass spectra were also compared with the data system library (NIST 11) [37]. Quantification of samples was conducted by the external standard method following the same procedure as that for samples.…”