Introduction |
Taxonomy |
Morphology |
Distribution |
Diet |
Size |
Aging |
Spawning |
Predation |
Extinction |

The Arctic Char, Salvelinus alpinus, in Ireland

Spawning
Char will spawn throughout their range, from high altitude lakes to Arctic rivers. Char congregate in large shoals at spawning time. In Ireland this is usually from late October to the end of November. They require a temperature of 6°C, but char eggs have hatched and alveins begun to feed at 3°C. The ideal temperature range for spawning and hatching is between 11° and 14°C. Above 14°C egg and alvein development is impaired.

Walnut sized gravels mixed with fist sized stones are the preferred substrate. Char will spawn in lotic and lentic environmnets, though all spawning populations know today in Ireland spawn in lakes. The char often spawn near the shore where wave action, and thus aeration, is highest. The movement of the water also would prevent depostion of fine materials and suspended solids which could smother the developing eggs. However, char are known to spawn at depths from 1–100m.

Eggs are large (4-5mm) and sticky. Females dig a redd in a territory defended by the male. Eggs hatch in the spring and the alveins begin to feed soon afterwards. Larger females lay larger eggs and dig deeper redds so their offspring have a better chance of survival. The deeper redds are resistant to subsequent redd digging by other females and the larger eggs allow for larger alveins better able to compete for food with other newly hatched char. In the event of a poor supply of food on hatching the larger yolk sac will enable the alvein to survive longer than his cohorts.  Fecundity has been difficult to measure. Mature females may produce between 500 and 7,000 eggs.