Michel Roggo / Rainbow trout alevins (Salmo gairdneri / Oncorhynchus mykiss) hatchery, Switzerland, 2003

Michel Roggo / Atlantic salmon alevins (Salmo salar) Europe, Captive

Michel Roggo / Brown trout alevins (Salmo trutta fario) in a hatchery, Europe, Captive

Wild Wonders of Europe / Roggo / European grayling (Thymallus thymallus) eggs, 17 days, from Lake Thun, Switzerland, captive, April 2009

Wild Wonders of Europe / Roggo / European grayling (Thymallus thymallus) alevins, 4 days, from Lake Thun, Thun, Switzerland, captive, April 2009

Jane Burton / Brown trout {Salmo trutta} one-week-old alevins on river gravel, captive, from Europe

Doc White / Pink salmon alevins (Oncorhynchus gorbuscha), newly hatched fish with yolk sacs attached. Alaska,

Doc White / Pink salmon alevins (Oncorhynchus gorbuscha), newly hatched fish with yolk sacs attached. Alaska,

Michel Roggo / Rainbow trout alevins (Salmo gairdneri / Oncorhynchus mykiss) hatchery, Switzerland, 2003

Michel Roggo / Brown trout alevins (Salmo trutta fario) in a hatchery, Europe, Captive

Michel Roggo / Atlantic salmon alevins (Salmo salar) Europe, Captive

Sergey Gorshkov / Sockeye Salmon (Oncorhynchus nerka) alevins and eggs, Kamchatka, Russia

Sergey Gorshkov / Sockeye Salmon (Oncorhynchus nerka) alevins and egg, Kamchatka, Russia

Wild Wonders of Europe / Roggo / European grayling (Thymallus thymallus) alevins, 18 days, feeding on zooplankton, from Lake Thun, Switzerland, captive, April 2009

Wild Wonders of Europe / Roggo / European grayling (Thymallus thymallus) alevins, 1 day old, with yolk sacs, from Lake Thun, Switzerland, captive, April 2009

Ingo Arndt / Brown Trout (Salmo trutta) alevins, Europe

Jane Burton / Brown trout {Salmo trutta} eggs and newly hatched alevins burrowing down into river gravel, captive, from Europe, life cycle sequence 7/14

Jane Burton / Brown trout {Salmo trutta} one-week-old alevins on river gravel, captive, from Europe, life cycle sequence 9/14

Jane Burton / Brown trout {Salmo trutta} one-week-old alevins on river gravel, captive, from Europe

Jane Burton / Brown trout {Salmo trutta} three/four-weeks-old alevins with freshwater Shrimp {Gammarus sp}, captive, from Europe, life cycle sequence 10/14

Jane Burton / Brown trout {Salmo trutta} newly hatched alevins and eggs ready to hatch, captive, from Europe, life cycle sequence 4/14

Jane Burton / Brown trout {Salmo trutta} newly hatched alevins and eggs ready to hatch, captive, from Europe, life cycle sequence 5/14

Jane Burton / Brown trout {Salmo trutta} three/four-weeks-old alevins, captive, from Europe

Jane Burton / Brown trout {Salmo trutta} newly hatched alevins and eggs ready to hatch, captive, from Europe, life cycle sequence 6/14

Hiroya Minakuchi / Chum Salmon (Oncorhynchus keta) alevins, native to the Pacific Ocean

Hiroya Minakuchi / Chum Salmon (Oncorhynchus keta) alevins, native to the Pacific Ocean

Hiroya Minakuchi / Chum Salmon (Oncorhynchus keta) eggs and alevins, native to the Pacific Ocean

Sergey Gorshkov / Sockeye Salmon (Oncorhynchus nerka) egg and alevins, Kamchatka, Russia

Sergey Gorshkov / Sockeye Salmon (Oncorhynchus nerka) alevins, Kamchatka, Russia

Sergey Gorshkov / Sockeye Salmon (Oncorhynchus nerka) at various life stages including eggs and alevins, Kamchatka, Russia

Sergey Gorshkov / Sockeye Salmon (Oncorhynchus nerka) alevins hiding in gravel, Kamchatka, Russia

Jane Burton / River / Brown trout {Salmo trutta} eggs and alevins (fry). Captive. UK.

Peter Mather / Chinook Salmon (Oncorhynchus tshawytscha) alevins recently hatched from eggs, Yukon River, Yukon, Canada