Physiological parameters for zebrafish include environmental factors, general physiological factors and blood values. The reference values for these parameters are listed in the tables below.
Environmental factors related to water quality
In the laboratory, it is important that zebrafish are being housed in systems where optimal monitoring and control of water quality can be guaranteed. There are no rigid standards; the parameters in use are guidelines based on the literature and on laboratory experience (see the table on Physical factors in the environment for details).
General physiological factors
| Factor (unit) | Values |
| Length and weight of adult fish (from 5–6 months) | 30–40 mm; 350–500 mg (females are slightly larger than males) |
| Lifespan | Up to 66 months (average 42 months); in practice: more welfareWelfare A complex and dynamic internal state that includes: successful biologic functioning, positive experiences, and absence of negative conditions. The animal adapts effectively to internal needs and external stimuli and maintains a good mental state. and health problems after 24 months |
| Respiration rate (movements per minute) | 80 (gill cover movements) |
| Number of chromosomes | 25 chromosomes (4n) |
| Sexual maturity | Sexual development: 1–3 months; initially, all individuals are female (juvenile ovaria); then transformation into males (with transformation of juvenile ovaria to testes) or into adult females (maturation of juvenile ovaria into adult ovaria) |
| Breeding age | After 3 months |
| Reproductive cycle | Females can produce eggs every few days (depending on their physical condition); for high-quality reproduction and the prevention of health problems, spawning is necessary once a week |
| Brood size | Dependent on the female’s condition and the particular zebrafish line; ranges from a few to as many as 1000; average: between 100–300 per female |
| Development | At 28.5 degrees Celsius; embryo (0–72 h): larva: >72 h post fertilization; first 24 h: segmentation, then organogenesis; hatching: 48–72 h post fertilization; self-feeding: 120–168 h post fertilization |
Blood values
The following values are indications based on various sources.
| Hematological parameters (unit) | Values (average ± 1 SD) | Remarks |
| Total blood volume (μl) | 20–25 | Based on the maximum obtainable blood sampling volume |
| HemoglobinHemoglobin Iron-containing pigment of red blood cells that carries oxygen to the body’s tissues via the bloodstream. (g/dL) | Males: 13.2 ± 0.8
Females: 13.1±1.9 |
|
| HematocritHematocrit The volume of red blood cells as a percentage of total blood volume. (% vol) | Males: 30.9 ± 5.5
Females: 26.7± 4.4 |
Males and females combined: 31.5 ± 5.7 |
| Leukocytes (× 10³/mm³) | ~80 | Distribution: lymphocytes (71–92%); monocytes (5–15%); neutrophils (2–18%); eosinophils (0–2%); basophils (0–2%) |
| Erythrocytes (×106/ μl) | 3.0 (range 2.9–3.2) | |
| Glucose (mg/dL) | 82.2 ± 12.0 (range 62.0–91.0) |
