Assessing sperm membrane viability using flow cytometry in farmed New Zealand giant kokopu Galaxias argenteus

Journal of Fish Biology

et al. 2021

We sought to determine a compatible anticoagulant for routine haematological and physiological assessments with giant kokopu (Galaxias argenteus), an endemic New Zealand fish. We observed that blood treated with lithium heparin (LH) rapidly coagulated and haemolysed, making it unsuitable for G. argenteus. Dipotassium ethylenediaminetetraacetic acid (K 2 EDTA) and trisodium citrate (citrate) effectively prevented blood coagulation. K 2 EDTA-treated erythrocytes exhibited the least mean haemolysis and mean corpuscular fragility. Further studies into prolonged storage effects of citrate and K 2 EDTA are recommended to find a compatible anticoagulant for use with G. argenteus blood.

Section: Galaxias Argenteus Peripheral Blood Clotting Time Parameters Parameter 1 × Pbs Citrate K2edta Lh – –mentioning

confidence: 99%

Effect of anticoagulants on farmed giant kokopu, Galaxias argenteus (Gmelin 1789) haematological parameters and erythrocyte fragility

Journal of Fish Biology

et al. 2021

“…The giant kokopu ( Galaxias argenteus ) is one of the five migratory galaxiid species endemic to New Zealand (Dunn et al ., 2018; Pearce et al ., 2018). Galaxiids are the most species‐rich freshwater fishes occupying the cool‐temperate waters of the southern hemispheres (McDowall, 2006).…”

Section: Introductionmentioning

confidence: 99%

Haematological and metabolic profiles associated with age and sex in giant kokopu (Galaxias argenteus) (Gmelin 1789) broodstock

Journal of Fish Biology

et al. 2021

This study characterized selected peripheral blood (PB) haematological parameters, liver, serum and muscle metabolic features in 3-and 5-year-old male and female giant kokopu (Galaxias argenteus) broodstock reared indoor at 16 C. Sex and age did not affect PB total cell count and haematocrit values. Nonetheless, higher erythrocytes in 5-year-old fish, elevated thrombocyte and lymphocyte counts in 3-year-old fish indicate age-specific cellular regulation. Higher thrombocyte counts in female fish suggest sex-specific regulation. At a metabolic level, liver abundance for long chain saturated fatty acids (FAs) was higher in males, whereas females had elevated levels of polyunsaturated FAs. Essential and non-essential amino acids (AAs) in liver and serum were also elevated in females compared to males. These findings suggest differential allocation of FAs and AAs to reflect requirements for gonadal, development and provisioning. Similarly, age significantly resulted in higher liver and serum abundances of some non-essential AAs in 3-year-olds compared to 5-year-old fish, suggesting higher metabolism in younger fish. Overall, results enhance our understanding of sex-and age-based differences in fish haematology, muscle, liver, and serum metabolite profiles in healthy G. argenteus. Future studies should carefully consider potential age-and sex-specific differences in metabolic responses.

“…The giant kokopu ( Galaxias argenteus ) (Gmelin 1789) is an amphidromous fish endemic to New Zealand (Pearce et al, 2018). The status of this species is considered as ‘at risk‐declining’ (Dunn et al, 2018) due to habitat loss (Bonnett & Sykes, 2002), competition from exotic brown trout ( Salmo trutta ), and whitebait fishing (David, 2002).…”

Section: Introductionmentioning

confidence: 99%

Haematological and metabolic profiles of brooder giant kokopu, Galaxias argenteus (Gmelin 1789) based on sex and temperature

et al. 2021

Aquaculture Research

This study assessed the selected peripheral blood haematological parameters and metabolite profiles linked to liver, serum and muscle samples in 3‐year‐old male (weight = 131.19 ± 29.24 g; total length = 21.33 ± 1.20 cm; n = 5) and female (122.96 ± 27.04 g; total length = 21.09 ± 1.09 cm; n = 5) giant kokopu (Galaxias argenteus) broodstock cultured at 12°C and 16°C. Temperature and sex did not influence haematocrit values or counts of total blood cells, erythrocytes and leucocytes. However, fish reared at 16°C had higher thrombocyte counts, whereas those kept at 12°C exhibited the highest proportion of lymphocytes. At the metabolic level, sex was the main factor that influenced metabolite levels across tissues, with particularly higher amino acid metabolites in liver of females. Changes linked to the interaction between temperature and sex showed significant differences in fatty acid profiles of liver, and in amino acids in muscle and serum samples. Males kept at 16°C exhibited decreased levels of myristic acid and nonadecanoic acid linked to homeoviscous adaptation. In females, levels for energy metabolites including tyrosine and aspartic acid (in muscle), and alanine (in serum) were disturbed at 16°C. The study provides insights into preliminary haematological and metabolic effects associated with sex and temperature in galaxiids.