Chinook eggs and alevin |
The 2012 brood of Dworshak Spring Chinook salmon have been nestled
in the security and darkness of incubation trays since spawning, way back in
August. In those trays eggs developed into alevin and alevin grew into fry. Fry
are notoriously hungry critters, as most animal babies are. They have used up
the nourishment contained in their yolk sac, have developed a working digestive
system and are ready to put it to use!
In hatchery speak we call these hungry little fry “swim-up
fry” because as these fish are ready start feeding they are also ready to start
swimming freely. In order to control their buoyancy (ability to move up and
down in the water) they must first fill a little balloon like organ called the swim
bladder. When the fish are put into raceways the first thing you see them do is
“swim up” to the surface and take gulps of air to fill their swim bladder.
The operation has gone very smoothly; the little fish look great and are already feeding well. They are off to very good start! By this time next year these Chinook will be making their way down river as smolts for life in the ocean.
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