Serum chemistry, thyroxine concentration, and blood cell morphology of wild, young Blackchin Guitarfish Glaucostegus cemiculus sampled on the eastern Mediterranean coastline

OBJECTIVE

The Blackchin Guitarfish Glaucostegus cemiculus is endemic to the Mediterranean Sea and is critically endangered, but relevant routine laboratory data are unavailable. Our objectives were to determine the packed cell volume (PCV), comprehensive serum chemistry analytes, and serum total thyroxine (sTT4) concentration; compare serum albumin and serum globulin concentrations as measured by two different methods; and describe the blood cell morphology of healthy, free-ranging Blackchin Guitarfish.

METHODS

Wild Blackchin Guitarfish were captured using a seine net. Blood samples for serum chemistry and hematological analyses were obtained and measured using routine laboratory methods. The fish were tagged and released.

RESULT

This study included 43 Blackchin Guitarfish (17 males and 26 females) that were younger than 6 months as estimated based on total length and body weight. The median PCV (n = 23) was 22% (minimum-maximum [min-max] = 15-25%). Median sTT4 (n = 10) measured by chemiluminescence immunoassay was 7.86 nmol/L (min-max = 7.52-9.57 nmol/L). The study included a comprehensive, 25-analyte serum chemistry analysis (e.g., serum iron and unbound and total iron-binding capacity) and a morphological description of all blood cells. Serum electrophoresis (SEP; n = 13) yielded a consistent serum albumin-migrating protein fraction and four globulin fractions. Serum electrophoretograms corroborating these results are presented.

CONCLUSION

In Blackchin Guitarfish, the serum albumin-migrating fraction measured by SEP combined with serum total protein concentration yields a much higher albumin concentration compared to that measured by bromocresol green spectrophotometry. The true identity of this albumin-migrating fraction remains to be identified. The analytes' calculated 2.5-97.5% interpercentile intervals should be considered as reference intervals applying to Blackchin Guitarfish of similar age but should be applied cautiously to adult fish.

Serum proteinogram of gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax) as a new useful approach for detecting loss of haemostasis

Proteinograms, a semiquantitative analytical method that separates proteins into multiple bands, have not been explored in teleosts for diagnostic or prognostic purposes. This study aimed to establish reference values for proteinograms in the serum of gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax), two important farmed fish species in the Mediterranean region. Serum proteins were studied using SDS-PAGE, electropherogram, and HPLC-mass spectrometry. SDS-PAGE analysis revealed four major bands of proteins around 11, 25, 70, and 100 kDa in the serum of gilthead seabream and European sea bass. Electropherogram results showed that a protein with a molecular weight of 76.8 kDa was the most abundant protein in the serum of gilthead seabream, while a peak of 75.5 kDa was the most abundant in European sea bass. HPLC-mass spectrometry detected 87 proteins and 119 proteins in the serum of gilthead seabream and European sea bass, respectively, including α1-globulins, α2-globulins, β-globulins, and γ-globulins. Notably, the albumin sequence was not detected in either of the two species. These results help to characterize the serum protein profile and to establish reference proteinograms for these two fish species. They also provide a basis for the development of novel approaches for the rapid detection of loss of haemostasis due to stress, health disorders or disease in farmed fish.

Comparative analysis of blood protein fractions in two mediterranean farmed fish: Dicentrarchus labrax and Sparus aurata

Total protein levels in fish are widely used in health and welfare studies, providing a simple and accessible measure. However, the multifaceted role of blood proteins makes it sometimes challenging to link total protein content to specific health issues, while specific protein fractions may offer more precise insights into fish biology and health, particularly in farmed fish species where such data is often lacking. Data were gathered from two experiments involving Dicentrarchus labrax and Sparus aurata, key species in European marine aquaculture. The aim was (1) to assess how different globulin fractions contribute to total protein content in blood and (2) how these contributions vary across different sampling times in healthy animals. In D. labrax, the beta1 globulin fraction emerged as the major contributor (34.16%), followed by albumin and alpha2 globulins (18.24% and 16.41%, respectively). In contrast, pre-albumins and alpha1 fractions had the least contribution (5.49% and 7.71%). S. aurata exhibited albumin as the primary contributor (23.39%), followed by beta1 and alpha2 globulins (19.71% and 19.15%, respectively), with gamma and alpha1 fractions contributing the least (5.34% and 8.63%). Notably, the study revealed relatively stable contributions of globulin fractions to total proteins within both species, albeit with minor variations over time, potentially linked to environmental and individual factors. Furthermore, larger fish displayed higher total protein levels. This research underscores the need for further investigation into the diverse factors influencing globulin contributions to total proteins, ultimately enhancing health and welfare monitoring for farmed fish species.

Factors Determining the Susceptibility of Fish to Effects of Human Pharmaceuticals

The increasing levels and frequencies at which active pharmaceutical ingredients (APIs) are being detected in the environment are of significant concern, especially considering the potential adverse effects they may have on nontarget species such as fish. With many pharmaceuticals lacking environmental risk assessments, there is a need to better define and understand the potential risks that APIs and their biotransformation products pose to fish, while still minimizing the use of experimental animals. There are both extrinsic (environment- and drug-related) and intrinsic (fish-related) factors that make fish potentially vulnerable to the effects of human drugs, but which are not necessarily captured in nonfish tests. This critical review explores these factors, particularly focusing on the distinctive physiological processes in fish that underlie drug absorption, distribution, metabolism, excretion and toxicity (ADMET). Focal points include the impact of fish life stage and species on drug absorption (A) via multiple routes; the potential implications of fish's unique blood pH and plasma composition on the distribution (D) of drug molecules throughout the body; how fish's endothermic nature and the varied expression and activity of drug-metabolizing enzymes in their tissues may affect drug metabolism (M); and how their distinctive physiologies may impact the relative contribution of different excretory organs to the excretion (E) of APIs and metabolites. These discussions give insight into where existing data on drug properties, pharmacokinetics and pharmacodynamics from mammalian and clinical studies may or may not help to inform on environmental risks of APIs in fish.

Peptide derived C. striata albumin as a natural angiotensin-converting enzyme inhibitor

As one of the most popular sources for fish albumin, Channa striata has been considered as a promising substitute for human albumin. However, scientific information regarding its genomic and proteomic is very limited, making its identification rather complicated. In this study, we aimed to isolate, characterize, and examine the bioactivity of protein and peptide derivatives of C. striata albumin. Fractionation of albumin from C. striata extract was conducted using Cohn Process and the yield was evaluated. The peptides were further produced by enzymatic hydrolysis. All these proteins were studied using tricine-SDS PAGE and tested for in vitro ACE inhibition. Dry weights of the Fraction-5, where the albumin was more abundant and purer, was 3.8 ± 2.1%. Based on tricine-SDS PAGE analysis, two bands of protein, e.g., approximately 10 and 13 kDa, were detected with highest intensity found in Fraction-5, which might be albumin of C. striata. An increasing trend of ACE inhibition by the fractions was observed, ranging from 7.09 to 22.99%. The highest ACEI activity was found in peptides from alcalase hydrolysis with molecular size <3 kDa (56.65 ± 2.32%, IC₅₀ 36.93 μg/mL). This value was also statistically significant compared with the non-hydrolyzed Fraction-5 and Parental Fraction, which were 23.48 ± 3.11% (P < 0.05) and 13.02 ± 0.68% (P < 0.01), respectively. Taken together, these findings suggest a promising potential of peptide-derived C. striata albumin for natural antihypertensive agents.

Species Differences in Tryptophan Metabolism and Disposition

Major species differences in tryptophan (Trp) metabolism and disposition exist with important physiological, functional and toxicity implications. Unlike mammalian and other species in which plasma Trp exists largely bound to albumin, teleosts and other aquatic species possess little or no albumin, such that Trp entry into their tissues is not hampered, neither is that of environmental chemicals and toxins, hence the need for strict measures to safeguard their aquatic environments. In species sensitive to toxicity of excess Trp, hepatic Trp 2,3-dioxygenase (TDO) lacks the free apoenzyme and its glucocorticoid induction mechanism. These species, which are largely herbivorous, however, dispose of Trp more rapidly and their TDO is activated by smaller doses of Trp than Trp-tolerant species. In general, sensitive species may possess a higher indoleamine 2,3-dioxygenase (IDO) activity which equips them to resist immune insults up to a point. Of the enzymes of the kynurenine pathway beyond TDO and IDO, 2-amino-3-carboxymuconic acid-6-semialdehyde decarboxylase (ACMSD) determines the extent of progress of the pathway towards NAD⁺ synthesis and its activity varies across species, with the domestic cat (Felis catus) being the leading species possessing the highest activity, hence its inability to utilise Trp for NAD⁺ synthesis. The paucity of current knowledge of Trp metabolism and disposition in wild carnivores, invertebrates and many other animal species described here underscores the need for further studies of the physiology of these species and its interaction with Trp metabolism.

Dietary brewer’s spent yeast enhances growth, hematological parameters, and innate immune responses at reducing fishmeal concentration in the diet of climbing perch, Anabas testudineus fingerlings

A 60-day feeding trial was conducted to optimally reduce the fishmeal level in climbing perch (Anabas testudineus) fingerling diet using a dietary brewer’s spent yeast biomass (BSY) based diet. In this study, five isonitrogenous (35% CP) and isocaloric (19.15 MJ/Kg) feeds were prepared by replacing 0 (BSY0), 25% (BSY25), 50% (BSY50), 75% (BSY75) and 100% (BSY100) of fishmeal protein using BSY protein. A total of 225 numbers of uniform-sized climbing perch fingerlings (3.29 ± 0.09 g) were randomly stocked in the 15 rectangular FRP (Fiber-reinforced plastic) tanks (150 L capacity). The experimental fish were fed twice daily at 4% BW for the first fortnight and later reduced to 3% BW based on satiation. At the end of the feeding trial, the weight gain (WG) of fish increased with the increasing BSY incorporation rates corresponding to fishmeal content and peaked at 77.88%, and beyond that, WG decreased. Food conversion ratios decreased as dietary BSY levels increased and peaked at 76.28%. All other growth and feed utilization parameters followed a similar trend of weight gain. Hepatosomatic index (HSI) and viscerosomatic index (VSI), A:G ratio, serum catalase activity, and monocytes were unaffected and the total serum protein, albumin, globulin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), respiratory burst activity, lysozyme levels, myeloperoxidase activity, hemoglobulin, red blood cells, white blood cells, neutrophils, eosinophils, lymphocytes, and gut protease activities were increased significantly (P < 0.05) with the increasing replacement levels and peaked between 25 and 75%. The serum SOD activity and total platelets were decreased, whereas the serum uric acid and gut amylase activities were increased significantly to the increasing levels of FM replacement in the diets (P < 0.05). Among treatments, the BSY100 resulted in an overall poor growth response combined with relatively reduced values in nearly all biochemical parameters. The whole-body composition was nearly unaffected. The integrated biomarker response of various biochemical indicators from the different treatments has shown that the 50% fishmeal protein can be optimally replaced by BSY, which would cause an 18% reduction in the Economic conversion ratio (ECR) and −270.28 gCO₂e^– reduction in carbon footprint value per kg of climbing perch fingerlings production.

Effects of caffeic acid on the growth performance, growth genes, digestive enzyme activity, and serum immune parameters of beluga (Huso huso)

Caffeic acid is a phenolic metabolite known for its beneficial pharmaceutical effects and is suggested as a functional additive for aquaculture. In this study, the effects of caffeic acid on the growth performance, growth genes, digestive enzyme activity, and serum immune parameters of beluga (Huso huso) were investigated. For this purpose, 120 beluga juveniles (367.75 ± 21.32 g) were divided into 12 tanks and fed with caffeic acid at rates of 0 (T0, control), 1 (T1), 5 (T2), and 10 (T3) g/kg for 56 days. The final weight and weight gain of beluga were significantly higher in fish fed 5 (T2) and 10 (T3) g caffeic acid/kg than in the control group and 1 (T1) g caffeic acid/kg. The specific growth rate was significantly higher in beluga fed 10 g caffeic acid/kg than 0 and 1 g/kg. Compared with the control group, the amylase, lipase, and pepsin activities were significantly higher in T2 and T3. The relative expression of growth hormone and insulin-like growth factor significantly increased in T3 compared with the control group. The expression of lipoprotein lipase and nuclear factor interleukin 3 of beluga fed 5 and 10 g caffeic acid/kg was higher than the control group. The lysozyme activity, total immunoglobulin, and total protein in the serum of beluga significantly increased in fish fed with caffeic acid at different rates compared with the control group. Based on the finding, the results suggested that the inclusion of caffeic acid (5-10 g/kg) in the diets of beluga is recommended to enhance the growth performance, some digestive enzyme activity, and serum immune parameters.

Trout and Human Plasma Protein Binding of Selected Pharmaceuticals Informs the Fish Plasma Model

Concerns are increasing that pharmaceuticals released into the environment pose a risk to nontarget organism such as fish. The fish plasma model is a read-across approach that uses human therapeutic blood plasma concentrations for estimating likely effects in fish. However, the fish plasma model neglects differences in plasma protein binding between fish and humans. Because binding data for fish plasma are scarce, the binding of 12 active pharmaceutical ingredients (APIs; acidic, basic, and neutral) to rainbow trout (Oncorhynchus mykiss) and human plasma was measured using solid-phase microextraction (SPME). The plasma/water distribution ratios (D _plasma/w ) of neutral and basic APIs were similar for trout and human plasma, differing by no more than a factor of 2.7 for a given API. For the acidic APIs, the D _plasma/w values of trout plasma were much lower than for human plasma, by up to a factor of 71 for naproxen. The lower affinity of the acidic APIs to trout plasma compared with human plasma suggests that the bioavailability of these APIs is higher in trout. Read-across approaches like the fish plasma model should account for differences in plasma protein binding to avoid over- or underestimation of effects in fish. For the acidic APIs, the effect ratio of the fish plasma model would increase by a factor of 5 to 60 if the unbound plasma concentrations were used to calculate the effect ratio. Environ Toxicol Chem 2022;41:559-568. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Effects of hydroxy-selenomethionine on performance, innate immune system and antioxidant defense of tambaqui (Colossoma macropomum) exposed to a physical stressor

Selenium (Se) is a mineral with natural antioxidant properties that constitutes a number of enzymes with a fundamental role in the immunity and antioxidant systems and may confer a protective role against oxidative stress in fish following exposure to physical stressors. Adopting an integrated approach, this study investigated simultaneously the role of hydroxy-selenomethionine (OH-SeMet) supplementation in performance, hematological parameters, innate immune, antioxidant capacity and tissue Se retention of tambaqui (Colossoma macropomum) and the possible protective role of dietary selenium when fish are exposed to a physical stressor (transport). Juvenile specimens (15.71 ± 1.90 g) were fed one of five diets: a basal unsupplemented diet (0.0 mg kg^-1 Se) or diets supplemented with OH-SeMet to provide 0.3, 0.6, 0.9 and 1.2 mg kg^-1 Se of diet for 75 days prior to subjection of fish to transport stress. Dietary supplementation with Se in the form of OH-SeMet for 75 days did not affect the production performance of juvenile tambaqui, but increased innate immunity parameters (oxidative burst) from the Se inclusion level of 0.6 mg kg^-1 and induced the activation of the antioxidant defense system (GPX, GSH and GST) especially at the Se inclusion level of 0.9 mg kg^-1. In addition, the Se content in the fillet rose significantly, as the OH-SeMet contents in the diet were increased. The stress caused by transport resulted in alterations in hematological parameters, blood protein profile and immune and enzymatic responses in the species. However, Se supplementation at 0.9 mg kg^-1 had a positive effect, increasing innate immunity and activating antioxidant defenses (CAT and GPx, especially) after this physical stressor was applied. These results demonstrate that, when submitted to transport stress, juvenile tambaqui use Se stored in the muscle and dietary supplementation with OH-SeMet at 0.9 mg kg^-1 improves the innate immunity and antioxidant system parameters of fish after transport. These findings reinforce the need for supplementing hydroxy-selenomethionine in commercial diets for tambaqui to ensure tissue Se reserves as a contingency in cases of stress.

Understanding the dynamics of physiological changes, protein expression, and PFAS in wildlife

Per- and polyfluoroalkyl substances (PFAS) accumulation and elimination in both wildlife and humans is largely attributed to PFAS interactions with proteins, including but not limited to organic anion transporters (OATs), fatty acid binding proteins (FABPs), and serum proteins such as albumin. In wildlife, changes in the biotic and abiotic environment (e.g. salinity, temperature, reproductive stage, and health status) often lead to dynamic and responsive physiological changes that alter the prevalence and location of many proteins, including PFAS-related proteins. Therefore, we hypothesize that if key PFAS-related proteins are impacted as a result of environmentally induced as well as biologically programmed physiological changes (e.g. reproduction), then PFAS that associate with those proteins will also be impacted. Changes in tissue distribution across tissues of PFAS due to these dynamics may have implications for wildlife studies where these chemicals are measured in biological matrices (e.g., serum, feathers, eggs). For example, failure to account for factors contributing to PFAS variability in a tissue may result in exposure misclassification as measured concentrations may not reflect average exposure levels. The goal of this review is to share general information with the PFAS research community on what biotic and abiotic changes might be important to consider when designing and interpreting a biomonitoring or an ecotoxicity based wildlife study. This review will also draw on parallels from the epidemiological discipline to improve study design in wildlife research. Overall, understanding these connections between biotic and abiotic environments, dynamic protein levels, PFAS levels measured in wildlife, and epidemiology serves to strengthen study design and study interpretation and thus strengthen conclusions derived from wildlife studies for years to come.

Hematological and serum biochemical reference intervals of rainbow trout, Oncorhynchus mykiss cultured in Himalayan aquaculture: Morphology, morphometrics and quantification of peripheral blood cells

De novo reference intervals (RIs) for a total of thirty two hematological and serum biochemical attributes were established for rainbow trout (Oncorhynchus mykiss) cultured in Himalayan aquaculture system. For this purpose, long term assessment of hemato-biochemical parameters was carried over a period of one year from March 2019 to February 2020 and a total of 444 blood samples were analysed. Blood examination results were recorded systematically and reference intervals were established, notably for erythrocyte parameters: hematocrit (Hct) 29–40%, hemoglobin 8.32–12.28 g/dL, red blood cell (RBC) count 1.01–2.04 (×10⁶/mm3); leukocyte parameters (x 10³/mm3): total leukocytes 31.32–90.60, neutrophils 4.21–18.85, total lymphocytes 20.55–63.63, small lymphocytes 14.86–46.50, large lymphocytes 6.35–22.34 and monocytes 1.22–7.56; thrombocyte count 23.00–68.00 (×10⁶/mm3). RIs were also established for red blood cell indices, vital serum constituents involved in carbohydrate, protein, lipid and nitrogen metabolism including the less known, diagnostically important, serum enzymes and electrolyte concentrations. Principal component analysis revealed that certain serum components were more efficient at distinguishing between the life stages (juvenile, adult) of fish by explaining about 92.7% of variation in the whole dataset compared to the principal hematological components which explained only about 80% of the variation. Significant (P < 0.05) differences were noted for RBC count, total leukocyte count (TLC), total protein, total cholesterol and uric acid with respect to the sex of fish. Moreover, clearly differentiable morphometric and morphological attributes were also noticed among erythrocytes, leukocytes (lymphocytes, neutrophils and monocytes) and thrombocytes. To our knowledge, the present study is the first of its kind that elucidates blood chemistry of cultured rainbow trout, O. mykiss in accordance to the guidelines framed by the American society of veterinary clinical pathologists (ASVCP). RIs reported here can help monitor the fish health status by improving the use of non-lethal diagnostics in piscine medicine.

Protein electrophoresis of non-traditional species: A review

EPH has been demonstrated to be a useful tool in companion animals while providing an opportunity to characterize globulinemias, including paraproteinemia. In EPH of non-traditional species, these same applications are important, but the primary use is to gauge the acute-phase and humoral immune responses. This includes the valid quantitation of albumin as well as the examination of fractions reflective of increases in acute-phase reactants and immunoglobulins. Agarose gel EPH and, more recently, capillary zone EPH have been applied to samples from these species. Performing these analyses provides special challenges in the placement of fraction delimits, generation of RIs, and interpretation of results. Recommended as part of routine bloodwork, EPH can also provide key results that are helpful in clinical and field-based health assessments as well as in prognostication.

Growth, serum biochemical parameters, salinity tolerance and antioxidant enzyme activity of rainbow trout (Oncorhynchus mykiss) in response to dietary taurine levels

This study evaluated the effect of dietary taurine levels on growth, serum biochemical parameters, salinity adaptability, and antioxidant activity of rainbow trout (Oncorhynchus mykiss). Four diets were formulated with taurine supplements at 0, 0.5, 1, and 2% w/v (abbreviated as T₀, T_0.5, T₁, and T₂, respectively). Rainbow trouts (initial weight of 80.09 ± 4.72 g) were stocked in tanks (180 L capacity), and were fed these diets for six weeks and subsequently underwent salinity acclimation. Physiological indicators were determined before salinity acclimation at 1, 4, 7, and 14 days afterwards. Results showed that there were no significant differences in growth performance (final mean weight ranged from 182.35 g to 198.48 g; percent weight gain was between 127.68% and 147.92%) of rainbow trout in freshwater stage, but dietary taurine supplement significantly increased serum-free taurine content. After entering seawater, the Na⁺-K⁺-ATPase activity of T₂ group returned to its freshwater levels, and the serum cortisol content was significantly higher than T₀ and T_0.5 groups. At the end of this experiment, the liver superoxide dismutase activity in the T₀ and T_0.5 groups was significantly lower than in the T₁ and T₂ groups, and the liver catalase in the T₀ group was the lowest whereas that in the T₂ group was the highest. Muscle malondialdehyde content was the highest in the T₀ group, and the lowest in the T₂ group. Based on the results of this study, supplement of dietary taurine (0.5-2%) enhanced the salinity tolerance in rainbow trout, which increased with the higher taurine concentration.

Changes in lipid biology during ovarian development in farmed beluga sturgeon, Huso huso L

The present study was conducted to understand key biochemical, physiological, and molecular changes associated with ovarian growth and with lipid transfer and/or accumulation into the ovary during oogenesis in captive beluga sturgeon. Plasma levels of triacylglycerides, cholesterol, phospholipid, and sex steroid hormones were determined and all were found to increase notably throughout development from the perinucleolar to the tertiary yolk stage. Using fast protein liquid chromatography, we recognized three major lipoprotein peaks in chromatograms from all samples. These peaks were characterized as containing very low-density lipoprotein (Vldl), low-density lipoprotein/high-density lipoprotein (Ldl/Hdl), and plasma proteins. While Ldl/Hdl represented the most abundant lipoprotein fraction, the relative abundance of different lipoprotein classes did not change with the stage of oogenesis. Eluted lipoproteins were separated using sodium dodecyl-sulfate polyacrylamide gel electrophoresis and sequenced. The peptide sequence spectra for 66-kDa, 205-kDa, 29-kDa, and 70-kDa bands matched with albumin, vitellogenin (Vtg) AB2b, immunoglobulin light-chain precursor, and immunoglobulin heavy-chain, respectively. The large amount of albumin in the plasma protein peak and the confined presence of Vtg AB2b to within Ldl/Hdl reinforce the lipoprotein classification. Lastly, transcript levels of genes encoding ovarian lipoprotein lipase (lpl), apolipoprotein E (apoe), very low-density lipoprotein receptors (vldlr), and low-density lipoprotein receptor-related protein 8-like (lrp8) were estimated using quantitative RT-PCR. The high mRNA levels of lpl, apoe, and lipoprotein receptors vldlr and lrp8 in previtellogenic females suggest that sturgeon oocytes need to be prepared to accept and traffic Vtg and lipids internally, before the start of vitellogenesis.

Identification of an albumin-like protein in plasma of Atlantic cod (Gadus morhua) and its biomarker potential for PAH contamination

Increased research efforts are currently focusing on Atlantic cod (Gadus morhua) and its significance for monitoring the contaminant situation in marine environments. Polycyclic aromatic hydrocarbons (PAHs) are well known toxic and carcinogenic compounds, thus continuous monitoring is required to ensure ecosystem sustainability and human food safety. A sensitive biomarker of PAH exposure in humans is the detection of PAH metabolites bound to albumin in blood. The potential of a similar PAH-albumin biomarker in Atlantic cod was therefore investigated by a desktop bioinformatic study followed by liquid chromatography mass spectrometry/mass spectrometry analysis of plasma from 16 fish. For the first time, an albumin-like protein in plasma of Atlantic cod is described, and the biomarker potential based on PAH-albumin adduct detection is discussed. Due to the detected low abundance of the albumin-like protein, it was found unlikely to be applicable as a new biomarker tool for evaluation of PAH exposure.

PLASMA PROTEIN ELECTROPHORESIS AND SELECT ACUTE PHASE PROTEINS IN HEALTHY BONNETHEAD SHARKS (SPHYRNA TIBURO) UNDER MANAGED CARE

Preventative health care of elasmobranchs is an important but understudied field of aquatic veterinary medicine. Evaluation of inflammation through the acute phase response is a valuable tool in health assessments. To better assess the health of bonnethead sharks ( Sphyrna tiburo ) under managed care, normal reference intervals of protein electrophoresis (EPH) and the acute phase proteins, C-reactive protein (CRP) and haptoglobin (HP), were established. Blood was collected from wild caught, captive raised bonnethead sharks housed at public aquaria. Lithium heparinized plasma was either submitted fresh or stored at -80°C prior to submission. Electrophoresis identified protein fractions with migration characteristics similar to other animals with albumin, α-1 globulin, α-2 globulin, β globulin, and γ globulin. These fractions were classified as fractions 1-5 as fractional contents are unknown in this species. Commercial reagents for CRP and HP were validated for use in bonnethead sharks. Reference intervals were established using the robust method recommended by the American Society for Veterinary Clinical Pathology for the calculation of 90% reference intervals. Once established, the diagnostic and clinical applicability of these reference intervals was used to assess blood from individuals with known infectious diseases that resulted in systemic inflammation and eventual death. Unhealthy bonnethead sharks had significantly decreased fraction 2, fraction 3, and fraction 3:4 ratio and significantly increased fraction 5, CRP, and HP. These findings advance our understanding of elasmobranch acute phase inflammatory response and health and aid clinicians in the diagnosis of inflammatory disease in bonnethead sharks.

A step toward simplified detection of serum albumin on SDS-PAGE using an environment-sensitive flavone sensor

In this study, we report a series of novel flavone-based sensors that exhibit a superior fluorescence response when interacting with serum albumin in real serum samples and in acrylamide gels. The detection limit of probe 4 for serum albumin solution is 0.09 μg mL(-1), and the detectable volume for monkey serum reaches as low as 0.03 μL.

Triacylglyceride physiology in the short-finned eel, Anguilla australis—changes throughout early oogenesis

During certain stages in an animal's life cycle, energy requirements may exceed energy intake from the diet. The spawning migration of temperate eels is a textbook example of negative energy balance, forcing these fish to rely on stored fats (triacylglycerides) to provide their muscles with energy for swimming and their growing oocytes with the nutrients needed to develop and support healthy offspring. We predicted broad implications of this great need for endogenous triacylglycerides in terms of their packaging, transport, and ovarian uptake. To test this, serum lipid concentrations and transcript abundances of intestinal and hepatic triacylglyceride packagers and ovarian triacylglyceride modifiers and receivers were investigated throughout previtellogenesis (feeding phase) and into early vitellogenesis (fasting phase) in short-finned eels. A switch from exogenous to endogenous triacylglyceride packaging was seen as the liver upregulated transcript levels of apolipoprotein B and microsomal triacylglyceride transport protein and downregulated those of apolipoprotein E and lipoprotein lipase. In the intestine, the reverse response was observed. Furthermore, ovarian transcript abundances of triacylglyceride modifiers and receivers increased (apolipoprotein E, lipoprotein lipase, and vitellogenin receptor), indicative of increased triacylglyceride uptake during previtellogenesis. We propose that increased hepatic apolipoprotein B production is a conserved vertebrate response to prolonged periods of negative energy balance.

Effects of waterborne Cu exposure in gilthead sea bream (Sparus aurata): a proteomic approach

Aquatic organisms may suffer from exposure to high Cu concentrations, since this metal is widely used in feed supplementation, in pesticide formulation and as antifouling. Chronic exposure to Cu, even at sub-lethal doses, may strongly affect fish physiology. To date, several biomarkers have been used to detect Cu exposure in fish producing contrasting results. Therefore, we used a proteomic approach to clarify how Cu exposure may affect the serum proteome of gilthead sea bream (Sparus aurata), since serum could be considered a good source of early-biomarkers of Cu toxicosis. For this purpose we exposed juvenile gilthead sea bream to waterborne Cu (0.5 mg/L). Our results indicate that fish tightly regulate circulating Cu levels, which are not affected by metal exposure. This homeostatic control is mainly achieved by the liver, able to excrete high amounts of the metal via bile. Cu exposure caused differential expression of several serum proteins, 10 of which were identified by Mascot and BLAST search. All these proteins, with the exception of growth hormone receptor and γ-glutamyl-carboxylase, can be related to: 1) Cu-induced hepatotoxicity (cytochrome oxidase subunit I, alanine aminotransferase, glutathione S-transferase); 2) potential immunosuppression due to interference of Cu with the inflammation/immunity network (α-1 antitrypsin, angiotensinogen, complement component C3, recombination-activating protein-1 and warm temperature acclimation-related 65 kDa protein).