All species of trout are born in
freshwater. Trout need to lay their eggs in either flowing river
water or in the case of some Lake/ Lough trout either in or close
to a feeder river or stream leading into the lake. The eggs need
good oxygen rich flow of fresh water to develop and eggs take approximately
30 days or more to hatch into "alevins", depending on
the temperature of the water.
Most river Brown trout spawn in early winter usually November &
December, in which they migrate upstream to spawn in the shallow
gravel beds in either the river itself or in the small tributaries
which lead into the river.
Alevins are the stage in which the eggs hatch out into tiny embryonic
fish that still have their yolk sac attached. At this stage of their
life they are still amongst the gravel redd. The term "Redd"
is a bed of loose gravel that fish use to spawn. The female digs
a trench or pit in the gravel, usually with her body and tail, she
then lays her eggs. At this critical stage the male trout releases
sperm over the eggs and the eggs are then covered over with gravel.
When the alevins yolk sac is used up of it's nutrients they then
turn into proper fry. After this stage they come up through the
gravel and start to feed.
It isn't long before the fry grow and quickly they look more like
a trout. They develop marks down their sides called Parr marks.
This is when they are now called "Parr". Depending on
the amount of food available to the fish, they can stay as parr
from 1 - 4 years until they become adult trout. At this stage any
sea going and Lough varieties of trout head down stream eventually
into the sea or Lough while the river trout start developing there
Trout can come into breeding condition from the age of 3 years upwards.
They then make their way to the spawning sites.
Sea trout and a lot of lake types of trout like our Dollaghan trout
tend to feed in shoals and then tend to run the river in loose shoals
as they make their way towards the gravel breeding grounds. They
tend not to eat or eat very little while they are in the river during
the spawning stage.
In contrast, the river trout, which are solitary feeders, remain
solitary as they move to the spawning grounds.
Trout choose their mates at the spawning sites and after they have
finished spawning the trout are known as "kelts" and they
then head back downstream again.
For reporting all environmental incidents
relating to water pollution in Northern Ireland phone - POLLUTION
HOTLINE 0800 807060
Club Bailiff - Derek Bell 07880898286