Effects of dietary Senecio scandens buch-ham extracts on growth performance, plasma biochemical, histology and the expression of immune-related genes in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀).

The study mainly aimed at the effects of dietary Senecio scandens buch-ham extract (SSBE) on the growth performance, body composition, plasma biochemical index, intestinal and liver histology and the expression of antioxidant, apoptosis and inflammatory related genes in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀). Basal diets supplemented with SSBE (10:1) 0%, 0.05%, 0.1%, 0.2% and 0.4% were fed hybrid grouper for 8 weeks. The results showed that WGR and SGR were significantly increased in the week 2 and week 4 in Diet 0.05% group (P < 0.05). The total protein, globulin and albumin significantly increased whereas alanine aminotransferase, triglyceride and alkaline phosphate in the plasma were significantly decreased in Diet 0.1% group (P < 0.05). The villi length, width, muscle thickness and the cross-sectional area of intestine were improved in Diet 0.05% and Diet 0.1% group. The expression levels of PPAR-α and CPT-1 in the liver of hybrid grouper were significantly increased following the supplementation of SSBE (P < 0.05). The expression levels of antioxidant related genes (CAT, GPX, GR and Keap1) and anti-inflammatory factor (IL-10) in liver, head kidney and spleen of hybrid grouper decreased significantly (P < 0.05). In addition, diets supplemented with 0.05%-0.1% SSBE had a good liver-protecting effect, but it would have a detrimental effect on hepatocytes when the content exceeds 0.2%. The above results indicated that the suitable additive amount of SSBE in hybrid grouper feed was 0.05%-0.1%.

Protective effects of seaweed supplemented diet on antioxidant and immune responses in European seabass (Dicentrarchus labrax) subjected to bacterial infection.

European seabass (Dicentrarchus labrax) production is often hampered by bacterial infections such as photobacteriosis caused by Photobacterium damselae subsp. piscicida (Phdp). Since diet can impact fish immunity, this work investigated the effect of dietary supplementation of 5% Gracilaria sp. aqueous extract (GRA) on seabass antioxidant capacity and resistance against Phdp. After infection, mortality was delayed in fish fed GRA, which also revealed increased lysozyme activity levels, as well as decreased lipid peroxidation, suggesting higher antioxidant capacity than in fish fed a control diet. Dietary GRA induced a down-regulation of hepatic stress-responsive heat shock proteins (grp-78, grp-170, grp-94, grp-75), while bacterial infection caused a down-regulation in antioxidant genes (prdx4 and mn-sod). Diet and infection interaction down-regulated the transcription levels of genes associated with oxidative stress response (prdx5 and gpx4) in liver. In head-kidney, GRA led to an up-regulation of genes associated with inflammation (il34, ccr9, cd33) and a down-regulation of genes related to cytokine signalling (mif, il1b, defb, a2m, myd88). Additionally, bacterial infection up-regulated immunoglobulins production (IgMs) and down-regulated the transcription of the antimicrobial peptide leap2 in head kidney. Overall, we found that GRA supplementation modulated seabass resistance to Phdp infection.

Effects of Probiotic Bacteria Bacillus on Growth Performance, Digestive Enzyme Activity, and Hematological Parameters of Asian Sea Bass, Lates calcarifer (Bloch).

This study was conducted to evaluate different doses of two species of Bacillus (Bacillus licheniformis and Bacillus subtilis), on growth parameters, chemical composition of fish, activity of liver, and digestive enzymes of Asian sea bass. During 8 weeks, juvenile Asian sea bass received diets supplemented with 1 × 103, 1 × 106, and 1 × 109 CFU g-1 probiotic in addition to a control diet without added microorganisms. At the end of the trial, growth indices (total weight, total length, specific growth rate, total weight gain, food conversion ratio, and condition factor), body composition (crude protein, crude lipid, ash, and dry matter), digestive enzymes (protease, lipase, and amylase), liver enzymes [aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP)], immunologic indicators (lysozyme), and hematological parameters [hematocrit (Hct), hemoglobin (Hb), red blood cells (RBCs), white blood cells (WBCs)] were assessed. Asian sea bass receiving diets supplemented with probiotic Bacillus (Bacillus licheniformis and Bacillus subtilis) showed significantly better growth than those fed the basal diet (control). Regarding body composition, total protein levels and dry matter were higher and lipid levels were lower in fish fed the diet containing 1 × 106 CFU g-1 probiotic compared with the control group (P < 0.05). Digestive enzymes (protease, lipase, and amylase) and hematological parameters (RBC, WBC, and Hb) were all highest in fish fed diet supplemented with 1 × 106 CFU g-1 probiotic Bacillus. Also, liver enzymes (AST, ALT, ALP) were lower in fish fed diet supplemented with 1 × 106 CFU g-1 probiotic Bacillus. Being that supplementation of 1 × 106 CFU g-1 of Bacillus in the diet is the dose which delivers the best results.

Combined effects of dietary low molecular weight sodium alginate and Pediococcus acidilactici MA18/5M on growth performance, haematological and innate immune responses of Asian sea bass (Lates calcalifer) juveniles.

Six weeks feeding trial was conducted to examine the effects of dietary administration of low molecular weight sodium alginate (LMWSA) and Pediococcus acidilactici MA 18/5M (PA) on humoral and mucosal immune responses, haematological parameters and growth performance, of Lates calcarifer juveniles. Fish (12.0 ±â€¯0.2 g) were fed experimental diets as follows: Control (diet 1, basal diet), 5 g kg-1 LMWSA (diet 2), 10 g kg-1 LMWSA (diet 3), 0.9 × 107 CFU g-1 PA (diet 4), 5 g kg-1 LMWSA + 0.9 × 107 CFU g-1 PA (Diet 5), and 10 g kg-1 LMWSA + 0.9 × 107 CFU g-1 PA (Diet 6). Results indicated a significant (P < 0.05) increase in innate immune parameters including serum lysozyme, bactericidal, hemolytic and respiratory burst activities as well as mucosal immune responses including lysozyme and bactericidal activities, when diet was supplemented with immunostimulants. Moreover, the combined effects of LMWSA with PA resulted in more pronounced immunological responses compared to the control and singular administration. Red and white blood cell counts significantly increased with either singular or combined administration of LMWSA and PA compared with the control group (P < 0.05). The singular administration of PA and combined supplementation of 5 g kg-1 LMWSA with PA significantly increased growth performance and feed intake compared with other experimental groups (P < 0.05). These results indicated that combined administration of LMWSA and PA can be considered as beneficial feed additive and immunostimulant in L. calcarifer juveniles.

Effects of dietary Spirulina platensis on growth performance, hematological and serum biochemical parameters, hepatic antioxidant status, immune responses and disease resistance of Coral trout Plectropomus leopardus (Lacepede, 1802).

The present study investigated the effects of dietary Spirulina platensis supplementation on growth performance, hematological and serum biochemical parameters, hepatic antioxidant status, immune responses and resistance to the pathogen infection in Coral trout Plectropomus leopardus. The fish were fed for 8-week with diets containing different levels of S. platensis: 0% (C), 2% (SP2), 4% (SP4), 6% (SP6), 8% (SP8) and 10% (SP10) as treatment groups, followed by a Vibrio harveyi infection test for 14 d. The study indicated that dietary supplementation with Spirulina platensis could significantly improve growth performance, and the highest weight gain rate (WGR) and specific growth rate (SGR) were observed in group SP10 (P < .05). Red cell count (RBC), white cell count (WBC), hemoglobin (Hb) and total antioxidant capacity (T-AOC) in the S. platensis supplemented groups were significantly higher than those of group C (P < .05). However, the levels of cholesterol, triglyceride and malondialdehyde (MDA) contents, and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities decreased with the increasing of dietary S. platensis levels. Compared with group C, the lysozyme (LYZ) and respiratory burst activities (RBA), and immunoglobulin (Ig) and complement contents in group SP4, SP6, SP8 and SP10 increased significantly than those of group C respectively (P < .05). After challenge with V. harveyi, the survival rate in group SP4, SP6, SP8 and SP10 was significantly higher than that of group C, and the highest survival rate was in group SP10 (P < .05). These results indicated that P. leopardus fed a diet supplemented with S. platensis (especially at 10%) could significantly promote its growth performance, improve its hepatic antioxidant status, and enhance its immune ability and resistance to V. harveyi infection.

Supplementation of arachidonic acid rich oil in European sea bass juveniles (Dicentrarchus labrax) diets: Effects on leucocytes and plasma fatty acid profiles, selected immune parameters and circulating prostaglandins levels.

The main objective of this study was to assess the effects of graded levels of dietary arachidonic acid (ARA), supplemented from alternative sources, on fatty acid composition of plasma and head kidney leucocytes of European sea bass (Dicentrarchus labrax). For that purpose, sea bass juveniles were fed four diets containing graded levels of ARA as follows: 0.5% (ARA0.5), 1% (ARA1), 2% (ARA2) and 4% (ARA4) during 60 days. At the end of the feeding trial fatty acid profiles of plasma and head kidney leucocytes were analyzed. Besides, plasma prostaglandins levels, head kidney leucocytes respiratory burst activity; peroxidase activity and phagocytic index were assayed. Reducing dietary ARA levels below 1% markedly reduced European sea bass growth performance. However, fish fed diet ARA0.5 tried to compensate this dietary ARA deficiency by a selective deposition of ARA on plasma and head kidney leucocytes, reaching similar levels to those fish fed diet ARA1 after 60 days of feeding. Nevertheless, head kidney phagocytic capacity was reduced as dietary ARA content in relation not only to variations on membrane composition but also to changes on fish basal prostaglandins levels. Results obtained demonstrated the importance to supply the necessary quantity n-6 LC-PUFA, and not only n-3 LC-PUFA levels, in European sea bass diets, in relation to not only growth performance but also immune system function.

Toxic effects on bioaccumulation and hematological parameters of juvenile rockfish Sebastes schlegelii exposed to dietary lead (Pb) and ascorbic acid.

Juvenile rockfish, Sebastes schlegelii (mean length 11.3 ± 1.2 cm, and mean weight 32.5 ± 4.1 g) were exposed for four weeks to dietary lead (Pb2+) at 0, 120, and 240 mg/L and ascorbic acid (AsA) at 100, 200, and 400 mg/L. The exposure concentrations and duration of significant Pb-induced accumulations in specific tissues of S. schlegelii were assessed. High levels of ascorbic acid significantly attenuated accumulations following exposure to dietary Pb. Dietary Pb exposure caused a significant increase in blood Pb concentrations, whereas red blood cell (RBC) count, hematocrit, and hemoglobin were significantly decreased. Notable changes were also observed in plasma calcium, magnesium, glucose, cholesterol, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvate transaminase (GPT). The growth performance of S. schlegelii was significantly decreased. High doses AsA supplemention were effective in attenuating the changes brought about by dietary Pb exposure.

Stress, nutrition and parental care in a teleost fish: exploring mechanisms with supplemental feeding and cortisol manipulation.

Parental care is an essential life-history component of reproduction for many animal species, and it entails a suite of behavioural and physiological investments to enhance offspring survival. These investments can incur costs to the parent, reducing their energetic and physiological condition, future reproductive capabilities and survival. In fishes, relatively few studies have focused on how these physiological costs are mediated. Male smallmouth bass provide parental care for developing offspring until the brood reaches independence. During this energetically demanding life stage, males cease active foraging as they vigorously defend their offspring. Experimental manipulation of cortisol levels (via implantation) and food (via supplemental feeding) in parental males was used to investigate the fitness consequences of parental care. Improving the nutritional condition of nest-guarding males increased their reproductive success by reducing premature nest abandonment. However, supplemental feeding and cortisol treatment had no effect on parental care behaviours. Cortisol treatment reduced plasma lymphocyte numbers, but increased neutrophil and monocyte concentrations, indicating a shift in immune function. Supplemental feeding improved the physiological condition of parental fish by reducing the accumulation of oxidative injury. Specifically, supplemental feeding reduced the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) on DNA nucleotides. Increasing the nutritional condition of parental fish can reduce the physiological cost associated with intensive parental activity and improve overall reproductive success, illustrating the importance of nutritional condition as a key modulator of parental fitness.

Tissue responsiveness to estradiol and genistein in the sea bass liver and scale.

As in mammals, estrogens in fish are essential for reproduction but also important regulators of mineral homeostasis. Fish scales are a non-conventional target tissue responsive to estradiol and constitute a good model to study mineralized tissues effects and mechanisms of action of estrogenic compounds, including phytoestrogens. The responsiveness to estradiol and the phytoestrogen genistein, was compared between the scales and the liver, a classical estrogenic target, in sea bass (Dicentrarchus labrax). Injection with estradiol and genistein significantly increased circulating vitellogenin (for both compounds) and mineral levels (estradiol only) and genistein also significantly increased scale enzymatic activities suggesting it increased mineral turnover. The repertoire, abundance and estrogenic regulation of nuclear estrogen receptors (ESR1, 2a and 2b) and membrane G-protein receptors (GPER and GPER-like) were different between liver and scales, which presumably explains the tissue-specific changes detected in estrogen-responsive gene expression. In scales changes in gene expression mainly consisted of small rapid increases, while in liver strong, sustained increases/decreases in gene expression occurred. Similar but not overlapping gene expression changes were observed in response to both estradiol and genistein. This study demonstrates for the first time the expression of membrane estrogen receptors in scales and that estrogens and phytoestrogens, to which fish may be exposed in the wild or in aquaculture, both affect liver and mineralized tissues in a tissue-specific manner.

Daily and seasonal expression of clock genes in the pituitary of the European sea bass (Dicentrarchus labrax).

The expression of select clock genes (clock, bmal, per1, per2, cry1, cry2) was investigated throughout the day and across the four seasons for two consecutive years in the pituitary of adult sea bass (Dicentrarchus labrax). A rhythmic pattern of daily expression was consistently observed in summer and autumn, while arrhythmicity was observed for some clock genes during spring and winter, concomitant with low water temperatures. The expression of clock and bmal showed highest values at the end of the day and during the night, while that of per and cry was mostly antiphasic, with high values during the day. Melatonin affects clock-gene expression in the pituitary of mammals. We therefore sought to test the effect of melatonin on clock-gene expression in the pituitary of sea bass both in vivo and in vitro. Melatonin modestly affected the expression of some clock genes (in particular cry genes) when added to the fish diet or the culture medium of pituitary glands. Our data show that clock genes display rhythmic daily expression in the pituitary of adult sea bass, which are profoundly modified according to the season. We suggest that the effect of photoperiod on clock gene expression may be mediated, at least in part, by melatonin, and that temperature may have a key role adjusting seasonal variations.

Sexually dimorphic transcriptomic responses in the teleostean hypothalamus: a case study with the organochlorine pesticide dieldrin.

Organochlorine pesticides (OCPs) such as dieldrin are a persistent class of aquatic pollutants that cause adverse neurological and reproductive effects in vertebrates. In this study, female and male largemouth bass (Micropterus salmoides) (LMB) were exposed to 3mg dieldrin/kg feed in a 2 month feeding exposure (August-October) to (1) determine if the hypothalamic transcript responses to dieldrin were conserved between the sexes; (2) characterize cell signaling cascades underlying dieldrin neurotoxicity; and (3) determine whether or not co-feeding with 17ß-estradiol (E(2)), a hormone with neuroprotective roles, mitigates responses in males to dieldrin. Despite also being a weak estrogen, dieldrin treatments did not elicit changes in reproductive endpoints (e.g. gonadosomatic index, vitellogenin, or plasma E(2)). Sub-network (SNEA) and gene set enrichment analysis (GSEA) revealed that neuro-hormone networks, neurotransmitter and nuclear receptor signaling, and the activin signaling network were altered by dieldrin exposure. Most striking was that the majority of cell pathways identified by the gene set enrichment were significantly increased in females while the majority of cell pathways were significantly decreased in males fed dieldrin. These data suggest that (1) there are sexually dimorphic responses in the teleost hypothalamus; (2) neurotransmitter systems are a target of dieldrin at the transcriptomics level; and (3) males co-fed dieldrin and E(2) had the fewest numbers of genes and cell pathways altered in the hypothalamus, suggesting that E(2) may mitigate the effects of dieldrin in the central nervous system.

Effects of garlic and ginger oils on hematological and biochemical variables of sea bass Dicentrarchus labrax.

This study was conducted to investigate the effects of garlic and ginger oils on hematological and biochemical health characteristics of sea bass Dicentrarchus labrax. Fish were exposed to garlic oil (0.01 or 0.02 mL/L), ginger oil (0.01 or 0.02 mL/L), or a combination of the two oils (each oil at a concentration of 0.005 or 0.01 mL/L) for 96 h via bath immersion. Results showed that the red blood cell count, hematocrit (%), hemoglobin (Hb) concentration (g/dL), mean corpuscular volume (µm(3)), mean corpuscular Hb (pg), and mean corpuscular Hb concentration (%) were not significantly affected by herb oil exposure. However, some changes in biochemical variables were observed. Sea bass exposed to the 0.005-mL/L garlic oil-ginger oil mixture exhibited a significant increase in serum glucose. Serum total protein and albumin levels decreased in sea bass that were exposed to a garlic oil-ginger oil mixture (0.005 or 0.01 mL/L) or to garlic oil at 0.02 mL/L. Serum globulin levels decreased and triglyceride levels increased in sea bass exposed to 0.02-mL/L garlic oil or to the 0.01-mL/L mixture. The serum lipase level decreased and the cholesterol level increased in fish that were exposed to 0.02-mL/L garlic oil. In summary, ginger oil at 0.01-0.02 mL/L can be used without negative effects, while the garlic oil or garlic oil-ginger oil mixture should be applied at a concentration below 0.005 mL/L for bath immersion of sea bass. This is the first study to examine how garlic oil and ginger oil exposure via bath immersion affects the hematological and biochemical status of sea bass.

Effects of in vivo chronic hydrocarbons pollution on sanitary status and immune system in sea bass (Dicentrarchus labrax L.).

Following the development of an experimental system to expose adult fish to low and stable concentration of pollutant over a prolonged period, the in vivo effects of hydrocarbons on sanitary status, i.e. the health status of fish with regard to chemical pollution, and immune system in sea bass, Dicentrarchus labrax were assessed. A total of 90 fish were acclimated for 15 days, then 45 fish were exposed to the water soluble fraction (WSF) of Arabian crude oil, similar to a complex pollution by hydrocarbons chronically observed in situ in estuaries, while the 45 other control fish sustained the same experimental conditions in clean seawater. After 21 days of exposure, 30 contaminated and control fish were sampled, then 30 other fish were collected after a 15 day recovery period in clean sea water. PAH concentrations in crude oil, WSF, muscles and bile were measured by gas chromatography coupled with mass spectrometry analysis. White blood cell counts and differential leucocyte counts were determined by classical haematology methods. Cell mortality and phagocytosis activity of leucocytes were analyzed by flow cytometry. Haemolytic alternative complement activity and stress parameters were analyzed in blood plasma by spectrophotometry. After a 21 day exposure period to a mixture of 41 parent/alkylated-PAHs (835 ± 52/85 ± 1 5 ng L(-1)). Fish flesh was contaminated by a bioconcentration of naphthalene very closed to the Reference Dose for Oral Exposure estimated by US-EPA's Integrated Risk Information System, causing a potential risk for human consumers. A leucopenia due to a lymphopenia, a rise in leucocyte mortality and a decrease in phagocytosis activity were noted in contaminated fish compared to controls. All these results may be explained by the damage to membrane cells integrity by uptake of PAHs and suggested an impairment of specific and nonspecific immune systems. After a 15 day recovery period, effects were reversible for sanitary status and an offset in immunity was noted by a significant increase in leucocytes in contaminated fish compared to controls.

Impact of an acoustic stimulus on the motility and blood parameters of European sea bass (Dicentrarchus labrax L.) and gilthead sea bream (Sparus aurata L.).

The physiological responses of fish to underwater noise are poorly understood and further information is needed to evaluate any possible negative effects of sound exposure. We exposed European sea bass and gilthead sea bream to a 0.1-1 kHz linear sweep (150 dB(rms) re 1 microPa). This band frequency is perceptible by many species of fish and is mainly produced by vessel traffic. We assessed the noise-induced motility reaction (analysing the movements) and the haematological responses (measuring blood glucose and lactate, and haematocrit levels). The noise exposure produced a significant increase in motility as well as an increase in lactate and haematocrit levels in sea bream and sea bass. A significant decrease of glucose was only observed in sea bream. A linear correlation between blood parameters and motility in fish exposed to the noise was observed. The acoustic stimulus produced intense muscle activity.

Effects of two oils and 16 pure polycyclic aromatic hydrocarbons on plasmatic immune parameters in the European sea bass, Dicentrarchus labrax (Linné).

The in vitro effects of polycyclic aromatic hydrocarbons (PAHs) on two plasmatic immune parameters, lysozyme concentration and haemolytic alternative complement activity, of the European sea bass, Dicentrarchus labrax, were tested using field (10(-7) and 10(-9) mg mL(-1)) and high concentrations (10(-3) and 10(-5) mg mL(-1)) observed during oil spills. Peripheral blood from 105 fish was collected, centrifuged at 1200 g, for 10 min, at 4 degrees C and three plasma pools, each of 35 fish, were constituted. Two oils (heavy fuel oil and light cycle oil) and 16 pure PAHs, selected on the basis of the American Environmental Protection Agency list (US EPA), were tested in vitro on the two humoral immune parameters. Only three pure PAHs (anthracene, chrysene and dibenz[a,h]anthracene) modulated lysozyme concentration. Acenaphthene, acenaphthylene, anthracene, benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, pyrene and light cycle oil modified the haemolytic alternative complement activity after 4h of incubation. This study investigates the direct effects of several PAHs on fish humoral immune functions and describes the haemolytic complement activity of fish as suitable biomarkers of oil pollution.

Waterborne and dietary hexavalent chromium exposure causes DNA-protein crosslink (DPX) formation in erythrocytes of largemouth bass (Micropterus salmoides).

Formation of DNA-protein crosslinks (DPXs) was demonstrated in erythrocytes from fathead minnows (Pimephales promelas) and largemouth bass (Micropterus salmoides) exposed to hexavalent chromium [Cr(VI)], a known carcinogenic and mutagenic metal contaminant of many industrial waterways. Tank water exposure of 2-3 in. fathead minnows to 2 ppm Cr(VI) led to significant DPX formation in erythrocytes, with over 140-200% elevations above background levels at 3-4 days, respectively. Largemouth bass exposed similarly were found to have 62% elevation of DPX levels after 4 days. When largemouth bass were fed a diet of minnows injected with 20 microg Cr(VI) for 5 days, a significant (p<0.01) increase of DPXs in erythrocytes was observed, with 80% elevation above erythrocytes from bass fed minnows injected only with saline. However, when largemouth bass were fed a diet exclusively of minnows exposed to 2 ppm Cr(VI) for 21 days, there was no significant difference in DPX levels compared to bass fed control (unexposed) minnows. This study provides evidence that DPX formation occurs in erythrocytes of fathead minnows exposed under controlled conditions to low ppm Cr(VI) concentrations, which is at or below concentrations previously assigned no observable effect levels. Furthermore, it appears that both waterborne and high dose dietary exposure to Cr(VI) can lead to DPX formation in erythrocytes of predatory fish species such as bass. However, it is unlikely that a bioconcentration of chromium in the food chain would be a major concern at these low ppm levels of exposure. Further, it may be difficult to achieve dietary Cr(VI) levels high enough to elicit DPXs in predatory fish under most environmental exposure scenarios.

Blood biochemical reference intervals for sunshine bass (Morone chrysops x Morone saxatilis) in three culture systems.

OBJECTIVE: To determine and compare biochemical reference intervals for sunshine bass (hybrid striped bass) from 3 culture systems. DESIGN: Observational comparison study. ANIMALS: Clinically normal sunshine bass (reciprocal hybrid striped bass, female Morone chrysops x male M saxatilis raised in high-density recirculating systems (80 g/L), low-density tanks (5 g/L) with biofilters, and cages (70 g/L) in a fresh water pond. PROCEDURE: Biochemical reference intervals were determined for fish from the different production systems following the National Committee for Clinical Laboratory Standards guidelines. Reference intervals from the 3 groups were compared. RESULTS: Reference intervals were significantly different between sunshine bass in the various culture systems. Though most of the differences in reference intervals were minor, fish in the high-density recirculating system had higher concentrations of total protein, albumin, globulin, creatinine, and phosphorus, and lower chloride values. There were no significant differences in glucose concentrations among the 3 groups of fish, and no differences in cortisol concentrations between fish in tanks and cages. CONCLUSIONS: Separate reference intervals should be developed for hybrid striped bass in different culture systems. CLINICAL RELEVANCE: Determining biochemical reference intervals for hybrid striped bass provides a tool to assess the health status of these fish.