Determination of hematology and plasma chemistry reference intervals for 3 populations of captive Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus)

Indexing serum and mucous biochemical parameters of endangered Chinese sturgeon Acipenser sinensis with implications for health assessment

The Chinese sturgeon (Acipenser sinensis) is a critically endangered aquatic fish. Health monitoring and welfare assessments are critical for the conservation of Chinese sturgeon. In this study, biochemical parameters of serum and skin mucus in Chinese sturgeon were examined to evaluate the potential biomarkers. Serum and mucous samples were obtained from Chinese sturgeon, and the levels of total protein (TP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), creatine kinase (CK), lactic acid (LD), acid phosphatase (ACP), lysozyme (LYZ), glucose (GLU), and cortisol were determined. The concentrations of ALT, AST, cortisol, and LYZ were significantly higher in the mucous group than those in the serum group (p < 0.05). In addition, the concentrations of ALP, ACP, LD, LDH, CK, and TP were significantly higher level in the serum group than those in the mucous group (p < 0.05). Moreover, the correlations between serum and mucous biochemical parameters were established. Statistical analysis showed a positive correlation between serum and skin mucous markers (ACP, cortisol, and LYZ). AST versus ALT in serum and mucus showed a significant positive correlation (p < 0.01). A significant positive correlation was found between cortisol and CK in mucus (p < 0.01). Moreover, LD versus LDH in serum showed a significant but weak positive correlation (p < 0.01). Principal component analysis revealed a complete separation between the serum and mucous groups, with the biomarkers that contributed the most being ALP, TP, ALT, and AST. This study provides baseline data and reference intervals for serum and mucous biochemical parameters in presumably healthy Chinese sturgeons. The current study has important implications for the development of conservation strategies and the conservation status of critically endangered species.

Assessment of hematological indicators, histological alterations, and DNA damage in Danube sturgeon (Acipenser gueldenstaedtii) exposed to the organophosphate malathion

This study focused on organophosphate malathion toxicity in Danube sturgeon (Acipenser gueldenstaedtii) and its negative effects in sub-lethal concentration. In this context, the LC50 value of fish exposed to five different concentrations and two different sub-lethal concentrations depending on the LC50 value were considered. Accordingly, LC50 of malathion for 96 h was 3.24 mg L-1. In leukocyte (WBC) and hemoglobin (HGB) such as hematological indicators, significant differences were observed in sub-lethal concentration (One-eighth of the LC50 =0.4 mg L-1). In addition, serious histological alterations were observed in the gill and liver tissues after both acute (96 h) and chronic periods (28 days). While epithelial lifting and hyperplasia were the most prominent lesions in the gill, intense vacuolization were observed in the liver. In addition, circulatory disturbances, regressive changes, and progressive changes in the gill and circulatory disturbances and inflammation in the liver were significantly higher for the chronic period. Finally, significantly higher DNA damage was detected in fish exposed malathion in the chronic period compared to the control group. In conclusion, the present study has proven that malathion has a hematological, histological and genotoxic effect on the endangered species A. gueldenstaedtii. Thus, the current study will motivate for residue studies on A. gueldenstaedtii and trigger conservation strategies for local governments.

Glucose and Lactate Reference Intervals for White Sturgeon and Evaluation of Two Point-of-Care Devices in Sturgeon Infected with Veronaea botryosa

White Sturgeon Acipenser transmontanus are cultured for human consumption as well as for conservation purposes. In this study, two commercially available portable devices for measuring glucose and lactate were compared to a benchtop analyzer and blood reference intervals were generated using heparin plasma collected from 43 healthy White Sturgeon yearlings. The generated normal ranges were used to compare plasma values collected from Veronaea botryosa-infected White Sturgeon at 10, 20, and 30 d postchallenge (dpc). In the 43 healthy yearlings, significantly different glucose and lactate values were obtained when comparing the portable devices to the benchtop analyzer. In the portable devices, blood glucose showed a consistent bias of 12.3 mg/dL and blood lactate showed a proportional bias. The detected blood glucose values in infected sturgeon were significantly different from those in noninfected controls when using the benchtop analyzer at 20 and 30 dpc and when using the portable device at 20 dpc. However, blood glucose in infected individuals and controls was within the reference interval on either device. No significant difference was noted for lactate measurements in infected sturgeon. The results of this study indicate that portable devices for blood glucose and blood lactate evaluation in White Sturgeon may be useful in a setting where relative values are an acceptable approximation of absolute values.

Anemia in salmon aquaculture: Scotland as a case study

Anemia in salmonid aquaculture is a recognized blood disorder resulting from the reduction of hemoglobin concentration and/or erythrocyte count. Because of sub-optimal oxygen supply to the tissues, as a negative impact of anemia fish will experience reduced growth and poor health. This health challenge may be linked with several factors including anthropogenic changes in the marine environment, infectious etiology (viral, bacterial, and parasitic), nutritional deficiencies, or hemorrhaging. From the mid-late summer of 2017 to 2019, Scottish salmon farming companies began to report the occurrence of anemic events in open-net marine sites. At that time, the industry had little understanding of the pathogenesis and possible mechanisms of anemia and limited the ability to formulate effective mitigation strategies. Clinical examination of fish raised suspicion of anemia and this was confirmed by generating a packed cell volume value by centrifugation of a microhematocrit tube of whole anticoagulated blood. Company health team members, including vets and biologists, reported discoloration of gills and local hemorrhages. This paper reviews various commercially significant cases and lesser-known cases of anemia in cultured salmonid species induced by various biological factors. The current methods available to assess hematology are addressed and some future methods that could be adopted in modern day fish farming are identified. An account of the most recent anemic event in Scottish farmed Atlantic salmon (Salmo salar) is presented and discussed as a case study from information provided by two major Scottish salmon producers. The percent of total marine sites (n = 80) included in this case study, that reported with suspected or clinical anemia covering the period mid-late summer 2017 to 2019, was between 1 and 13%. The findings from this case study suggest that anemia experienced in most cases was regenerative and most likely linked to blood loss from the gills.

Sablefish (Anoplopoma fimbra Pallas, 1814) plasma biochemistry and hematology reference intervals including blood cell morphology

Plasma biochemistry and hematology reference intervals are integral health assessment tools in all medical fields, including aquatic animal health. As sablefish (Anoplopoma fimbria) are becoming aquaculturally and economically more important, this manuscript provides essential reference intervals (RI) for their plasma biochemistry and hematology along with reference photomicrographs of blood cells in healthy, fasted sablefish. Blood cell morphology can differ between fish species. In addition, blood cell counts and blood chemistry can vary between fish species, demographics, water conditions, seasons, diets, and culture systems, which precludes the use of RI's from other fish species. For this study, blood was collected for plasma biochemistry and hematology analysis between June 20 and July 18, 2019, from healthy, yearling sablefish, hatched and reared in captivity on a commercial diet. Overnight fast of 16-18 hours did not sufficiently reduce lipids in the blood, which led to visible lipemia and frequent rupture of blood cells during analysis. Therefore, sablefish should be fasted for 24 to 36 hours before blood is collected to reduce hematology artifacts or possible reagent interference in plasma biochemistry analysis. Lymphocytes were the most dominant leukocytes (98%), while eosinophils were rare, and basophils were not detected in sablefish. Neutrophils were very large cells with Döhle bodies. In mammals and avian species, Döhle bodies are usually signs of toxic change from inflammation, but no such association was found in these fish. In conclusion, lipemia can interfere with sablefish blood analysis, and available removal methods should be evaluated as fasting for up to 36 h might not always be feasible. Also, more studies are required to establish RI for different developmental stages and rearing conditions.

Hematology and Biochemistry Panel Reference Intervals for Captive Saddleback Clownfish Amphiprion polymnus and Tomato Clownfish A. frenatus

Reference intervals of blood analytes are important diagnostic tools that clinicians use as a basis for making clinical decisions and that have been documented for many fish species. Although the effects of dietary supplementation on hematology and blood biochemistry variables in clownfish have been shown, there are no published reference intervals to date for routine hematology and blood biochemistry panels for these popular cultured marine fish (including Amphiprion spp.). The objective of this study was to establish de novo reference intervals for selected hemogram data and, using whole-blood analysis, commonly utilized chemistry analytes in two species of aquacultured clownfish: the Tomato Clownfish Amphiprion frenatus and Saddleback Clownfish A. polymnus. This study is based on blood samples from 25 clinically normal Tomato Clownfish and 38 clinically normal Saddleback Clownfish from two clownfish production facilities in Florida. Guidelines by the American Society for Veterinary Clinical Pathology were followed to generate robust reference intervals from the data collected. We report descriptive statistics and reference intervals for several hematology (n = 12) and biochemistry (n = 8) analytes using a small sample size and a small amount of blood per sample. The blood analyte data from this study are comparable with hematology and biochemistry data that have been reported in other teleost species. These results provide baseline health data for clownfish species that can be used in various clinical settings while also serving as a springboard for further research studies.

The Iconic Atlantic Goliath Grouper (Epinephelus itajara): A Comprehensive Assessment of Health Indices in the Southeastern United States Population

The Atlantic Goliath Grouper (Epinephelus itajara) population has rebounded from near extinction to an international status as vulnerable due in part to regional species recovery efforts. The southeastern US population has been recovering with the main spawning locations off the coasts of Florida. Despite their economic importance to the catch-and-release fishery and the dive industry, and their ecological importance as ecosystem engineers resulting in positive impacts on reefs and species richness, baseline health assessment information is very limited in this species to date. The objectives of this study were to: (1) establish reference intervals for hematological and plasma biochemical analytes, and report immune function, oxidative stress, and vitellogenin in mature males and females; (2) evaluate total length, age, and sex in relation to blood analytes in juvenile and mature fish; (3) assess analytes across sampled months in mature male and female fish; and (4) describe the typical light microscopy findings in liver and gill biopsies, including quantitative assessment of pigmented macrophage aggregates. Health indices are reported as reference intervals when applicable, or otherwise descriptively. Blood analyte correlations with length and age, sex differences, and comparisons across months provided relevant physiological considerations, including differences in protein/energy metabolism, tissue growth, sexual maturation, active reproduction, and antigenic stimulation. Liver histology identified changes associated with life stage, active reproduction, or of subclinically to clinically insignificant infectious and/or inflammatory processes. Hepatocellular vacuolation and pigmented macrophage aggregates were prominent. Pigmented macrophage aggregates correlated with total length, presumably from continuous antigenic stimulation and/or metabolic changes as fish grow. Gill histological findings were subtle. The data presented herein provide an essential baseline assessment of a suite of health variables in an iconic marine teleost species, serves as a springboard for future studies relevant to conservation physiology, and allows for population-level applications for conservation management and policy.

Hematological parameters in largemouth bass (Micropterus salmoides) with formalin-preservation: comparison between wild tournament-caught and captive-raised fish

BACKGROUND

Largemouth bass (Micropterus salmoides) are an economically important freshwater fish species that have been investigated for both the short and long-term effects of stress, secondary to angling. Limited data has been published on the hematological parameters of this species and blood sample stability is a notable limitation of hematologic field studies. A relatively novel technique using 10% neutral buffered formalin preserves heparinized whole blood and maintains blood cell stability beyond one month in striped bass. The objective of this study was to evaluate the differences in hematological parameters between tournament-caught and captive-raised largemouth bass using whole blood preservation with neutral buffered formalin.

METHODS

Two populations of largemouth bass (n = 26 wild; n = 29 captive) underwent coccygeal venipuncture to collect heparinized whole blood for packed cell volume, total solids, and manual differential. Formalin preservation of heparinized whole blood facilitated manual hemocytometer analysis. Results were compared between the populations (tournament-caught, and captive-raised) with Wilcoxon rank sum test, a Hotelling's T 2 test, and Bonferroni simultaneous 95% confidence intervals to determine significance.

RESULTS

The mean packed cell volume (44.9 ± 5.4%) and total solids (7.2 ± 1.1 g/dL) were significantly higher, while the total leukocyte count (7.08 ± 1.86 × 103/µL) was significantly lower in the wild tournament-caught population of largemouth bass, as compared to the captive-raised counterparts (PCV 34.4 ± 7.2%; TS 5.2 ± 1.0 g/dL; WBC 16.43 ± 8.37 × 103/µL). The wild population demonstrated a significantly distinct leukogram characterized by a neutropenia (24.1 ± 12.7%), lymphocytosis (67.7 ± 13.0%), and monocytopenia (8.3 ± 2.9%), while the erythrocyte and thrombocyte counts were not significantly different between populations.

DISCUSSION

Numerous factors have been demonstrated to influence hematologic parameters in fish including age, size, sex, temperature, environmental oxygen level, population density, and infection. The wild population endured stress during angling capture, live-well hypoxia, transport, and extended air exposures at weigh in, which may have caused a stress leukopenia as well as osmoregulatory dysfunction and subsequent hemoconcentration. Further evaluation of seasonal impact as well as increased sample size is warranted to enhance our understanding of largemouth bass hematology.

CONCLUSION

This study concluded that wild largemouth bass captured via tournament angling have higher packed cell volume and total solids, and lower total leukocyte counts, compared to captive-reared individuals. Through the completion of this study, we demonstrated the successful use of 10% neutral buffered formalin to preserve heparinized whole blood for precise hemocytometer cell counts in a new teleost species, the largemouth bass.

Sex-specific reference intervals of hematologic and biochemical analytes in Sprague-Dawley rats using the nonparametric rank percentile method

BACKGROUND

Hematologic and biochemical analytes of Sprague-Dawley rats are commonly used to determine effects that were induced by treatment and to evaluate organ dysfunction in toxicological safety assessments, but reference intervals have not been well established for these analytes. Reference intervals as presently defined for these analytes in Sprague-Dawley rats have not used internationally recommended statistical method nor stratified by sex. Thus, we aimed to establish sex-specific reference intervals for hematologic and biochemical parameters in Sprague-Dawley rats according to Clinical and Laboratory Standards Institute C28-A3 and American Society for Veterinary Clinical Pathology guideline.

METHODS

Hematology and biochemistry blood samples were collected from 500 healthy Sprague-Dawley rats (250 males and 250 females) in the control groups. We measured 24 hematologic analytes with the Sysmex XT-2100i analyzer, 9 biochemical analytes with the Olympus AU400 analyzer. We then determined statistically relevant sex partitions and calculated reference intervals, including corresponding 90% confidence intervals, using nonparametric rank percentile method.

RESULTS

We observed that most hematologic and biochemical analytes of Sprague-Dawley rats were significantly influenced by sex. Males had higher hemoglobin, hematocrit, red blood cell count, red cell distribution width, mean corpuscular volume, mean corpuscular hemoglobin, white blood cell count, neutrophils, lymphocytes, monocytes, percentage of neutrophils, percentage of monocytes, alanine aminotransferase, aspartate aminotransferase, and triglycerides compared to females. Females had higher mean corpuscular hemoglobin concentration, plateletcrit, platelet count, eosinophils, percentage of lymphocytes, percentage of eosinophils, creatinine, glucose, total cholesterol and urea compared to males. Sex partition was required for most hematologic and biochemical analytes in Sprague-Dawley rats. We established sex-specific reference intervals, including corresponding 90% confidence intervals, for Sprague-Dawley rats.

CONCLUSIONS

Understanding the significant discrepancies in hematologic and biochemical analytes between male and female Sprague-Dawley rats provides important insight into physiological effects in test rats. Establishment of locally sex-specific reference intervals allows a more precise evaluation of animal quality and experimental results of Sprague-Dawley rats in our toxicology safety assessment.