Northcote, T.G. (1993) A review of management and enhancement options for the Arctic grayling (Thymallus arcticus) with special reference to Williston Reservoir watershed in British Columbia.
British Columbia Ministry of Environment, Lands and Parks
| Species | Development state | Trait | Primary Data | Secondary Data |
| Thymallus thymallus | Egg | Oocyte diameter | As low as 2.0 up to 3.5 even 4.0 in Europe [Not specified] | 2.0 mm |
| Thymallus thymallus | Egg | Degree-days for incubation | 180-200 | 190.0 °C * day |
| Thymallus thymallus | Larvae | Initial larval size | 10-12 [size at hatching] | 11.0 mm |
| Thymallus thymallus | Larvae | Temperature during larval development | 12-18 [Between 12-18 the larvae spend 5 to 10 days in the gravel] | 15.0 °C |
| Thymallus thymallus | Female | Absolute fecundity | From a low of 1.5 to a high over 36 | 1.5 thousand eggs |
| Thymallus thymallus | Spawning conditions | Spawning season | Late March-April to June | ['March', 'April', 'June'] |
| Thymallus thymallus | Spawning conditions | Spawning temperature | 4 to 7, but sometimes up to 15 | 4.0 °C |
| Thymallus thymallus | Spawning conditions | Spawning water type | European grayling are mainly a river fish, but those in slow flowing parts of rivers migrate to faster flowing tributaries near spawning time, and lae populations all depend on streams for spawning | Flowing or turbulent water |
| Thymallus thymallus | Spawning conditions | Spawning substrate | Fine gravel shallows with moderate current | Lithophils |
| Thymallus thymallus | Spawning conditions | Spawning site preparation | Spawning territories set up by the males | No category |
| Thymallus thymallus | Spawning conditions | Nycthemeral period of oviposition | Latter part of the day near the diel temperature maximum | Day |
| Thymallus arcticus | Egg | Oocyte diameter | 2-3 [Prior to fertilization] | 2.5 mm |
| Thymallus arcticus | Egg | Egg adhesiveness | Slightly adhesive | Adhesive |
| Thymallus arcticus | Egg | Temperature for incubation | Full range 5.8-15.5, but mainly 7-9 | 10.65 °C |
| Thymallus arcticus | Larvae | Initial larval size | From 7-11 to 14-15 at emergence | 9.0 mm |
| Thymallus arcticus | Larvae | Larvae behaviour | Remain in the gravel during 3-4 days | Demersal |
| Thymallus arcticus | Female | Age at sexual maturity | A few reach sexual maturiy at age 3, about a quarter at age 4 and all by age 5 [Sex not specified] | 3.0 year |
| Thymallus arcticus | Female | Relative fecundity | Range from 6.475 to 16.887 or a mean of 10.915 in different regions | 6.47 thousand eggs/kg |
| Thymallus arcticus | Male | Age at sexual maturity | A few reach sexual maturiy at age 3, about a quarter at age 4 and all by age 5 [Sex not specified] | 3.0 years |
| Thymallus arcticus | Male | Weight at sexual maturity | Spawning males may be larger than females at a given age | No data |
| Thymallus arcticus | Spawning conditions | Spawning migration distance | Grayling made a post-spawning migration extending a 65 km stretch of the mainstream river | 65.0 km |
| Thymallus arcticus | Spawning conditions | Spawning migration period | Often moving onto spawning areas shortly after ice-out at temperatures near 4°C, usually occur in mid-May | ['May'] |
| Thymallus arcticus | Spawning conditions | Homing | Reproductive homing may be involved | Present |
| Thymallus arcticus | Spawning conditions | Spawning season | Spring spawners: mid-to late May and mid July [Some as early as April and others as late as July] | ['April', 'May', 'June', 'July'] |
| Thymallus arcticus | Spawning conditions | Spawning temperature | 5-9 | 7.0 °C |
| Thymallus arcticus | Spawning conditions | Spawning water type | Mainstream river tributaries and side-channels, tributary streams, also in lakes | Stagnant water |
| Thymallus arcticus | Spawning conditions | Spawning depth | 10-40 cm | 25.0 m |
| Thymallus arcticus | Spawning conditions | Spawning substrate | Coarse gravel | Lithophils |
| Thymallus arcticus | Spawning conditions | Spawning site preparation | Males set up and hold spawning territories of 6 to 7 m² rather than defending access to female [Redds are not constructed by females] | Susbtrate chooser |
| Thymallus arcticus | Spawning conditions | Nycthemeral period of oviposition | Most spawning is said to take place in mid to late afternoon, but some said that most spawning occurred in evening or night | Night |
| Thymallus arcticus | Spawning conditions | Parity | Once reaching sexual maturity, grayling may spawn every year, although they do not necessarily do so | Iteroparous |
| Thymallus arcticus | Spawning conditions | Parental care | Redds are not constructed or covered by the female | No category |