Haematological and serum biochemical profile of the upside-down catfish, Synodontis membranacea Geoffroy Saint Hilaire from Jebba Lake, Nigeria

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.

Haematological profile, blood cell characteristic and serum biochemical composition of cultured brown trout, Salmo trutta fario with respect to sex

The purpose of this research is to see how sex affects several haematological, biochemical and blood cell morphology in cultured brown trout, Salmo trutta fario. Different haematological parameters, for instance haemoglobin (Hb) concentration, haematocrit (Hct), red blood cell (RBC) and white blood cell (WBC) counts, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) and serum biochemical parameters such as glucose, cholesterol, total protein, albumin, globulin, alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), sodium, potassium and phosphorus were analysed. Throughout the study period, male fish had considerably greater Hb content, RBC count and Hct content than female fish, but insignificant (P > 0.05) difference in WBC count, differential leucocyte count, MCV, MCH and MCHC was seen between the two sexes of Salmo trutta fario. The majority of biochemical markers showed no significant (P > 0.05) difference, with the exception of AST, ALP, sodium, potassium, and phosphorus, which showed a significant (P < 0.05) difference. Under light microscopy, RBC and differential leukocyte count (neutrophils, lymphocytes, and monocytes) as well as thrombocytes were characterised and discriminated, revealing that the majority of the cells were normal and intact in shape. As a result of the foregoing findings, it is suggested that the data generated be used to identify the health state of fish and to determine the occurrence of various clinical and subclinical disorders, which might assist in enhancing the overall fish population production.

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.

Haematological and serum biochemical reference values of snow trout, Schizothorax labiatus habiting in river Sindh of Indian Himalayan region

Haematological and serum biochemical parameters are a valuable tool in determining the wellbeing status of different fish species and response in close association to various biological and environmental factors, therefore the aim of the present study was to establish sex-wise reference values of haemato-biochemical parameters of S. labiatus. The haematological parameters such as haemoglobin (Hb) concentration, total erythrocyte count (RBC), total leucocyte count (WBC), packed cell volume (PCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), mean corpuscular volume (MCV) and serum biochemical parameters such as glucose, cholesterol, urea, total protein, albumin and globulin were analysed. The results revealed that the haematological parameters, i.e., Hb, RBC, WBC and PCV showed significant (P < 0.05) differences with respect to sex. Significantly (P < 0.05) higher values of Hb content (11.18 g dl^-1 ), RBC count (1.88 × 10⁶  mm^-3 ) and PCV (36.15%) were noted in male fish than females throughout the study period, while significantly (P < 0.05) higher WBC count was noted in females (20.38 × 10³  mm^-3 ) compared to males. However, no significant (P > 0.05) difference was observed in erythrocyte indices like MCH, MCHC and MCV between sexes. The serum biochemical parameters, i.e., glucose, cholesterol and urea, also showed significant (P < 0.05) difference between the sexes, but no significant (P > 0.05) difference was noticed in total protein, albumin and globulin. Significantly (P < 0.05) highest values of glucose (116.76 mg dl^-1 ) and urea (9.01 mg dl^-1 ) were recorded in male S. labiatus, while highest value of cholesterol (223.53 mg dl^-1 ) was noted in females. The information generated in the present study gives the basic reference values of haematological and serum biochemical parameters of S. labiatus which will be useful in monitoring the wellbeing status of fish populations. Moreover, the data will also be helpful to ascertain the occurrence of different clinical and subclinical diseases, which may in turn help to boost the overall production of this species.

The haematology of six species of native catfish from northern Australia

Haematology has the potential to be a valuable tool in determining the health status of wild fish populations and wider ecosystem health. However, limited haematological data are available for wild Australian fish species, and the interpretation and nomenclature of leukocytes is variable and inconsistent in fish. The morphology and cytochemical reactions of erythrocytes, thrombocytes and leukocytes of 189 wild eel-tailed catfish (Tandanus tandanus), Wet Tropics tandan (Tandanus tropicanus), Hyrtyl’s tandan (Neosilurus hyrtlii), black catfish (Neosilurus ater), lesser salmon catfish (Neoarius graeffei), and silver cobbler (Neoarius midgleyi) are described. Erythrocytes, thrombocytes, lymphocytes, monocytes and heterophils in all six species are morphologically similar to those reported in other Siluriformes. Basophils and eosinophils are rarely reported in fish; however basophils were observed in peripheral blood smears of T. tropicanus and N. ater, and eosinophils were observed in N. graeffei. Periodic acid Schiff positive granular leukocytes were observed in N. graeffei, N. midgleyi, N. ater and T. tandanus. This is the first report on the leukocyte morphology and cytochemistry of any native Australian catfish species, and provides useful baseline data for future assessments of fish health and ecosystem integrity in Australia.