Dolly Varden

(Salvelinus malma)
Dolly Varden

Dolly Varden are a species of char, closely related to the Arctic char, Lake trout and Brook trout. Dolly Varden are found throughout arctic and subarctic regions worldwide. Within the Togiak National Wildlife Refuge, Dolly Varden are thought to be primarily anadromous. Unlike many other anadromous fish, such as salmon, Dolly Varden do not die after spawning and may spawn several times throughout their life. 

Dolly Varden have an elongated body shape with a rounded snout. The head is sometimes elongated, especially in breeding males, with large jaws that extend to behind the eyes. Color can vary according to maturity, time of year, whether the fish is found in fresh or salt water, and genetic background. Migrating fish, either fresh from the sea or not in spawning condition, are usually dark green on the back with silvery sides and white underneath. Their spots can range from very faint to bright pink to red. Occasionally the Dolly Varden may have vermiculations (worm-like markings) on their backs.  

Prior to spawning both male and female Dolly Varden can exhibit a variety of color combinations as they change to their full spawning colors. At spawning males become bright red, orange, pink and black with their fins becoming dark red to black with a pure white leading edge on the lower fins. Spawning males usually develop a kype, or hook, on their lower jaw. Females darken slightly and may have black operculums, bright pink or red spots and fins. Dolly Varden can be differentiated from Arctic char by the Dolly Varden having black pigment in the mouth or on the head, square or very slightly forked tail, thick caudal peduncle, and more reddish spawning colors.  

Dolly Varden feed on a variety of different food items from zooplankton and insects to fish depending on their age, size and location. They are known to be highly piscivorous, feeding on salmon fry, juvenile smolts and their own young when available. Other small fish such as smelt, capelin, and sandlance, and juveniles of larger fish probably provide a substantial portion of the Dolly Varden's diet while they are at sea. 

During the salmon runs it is likely that salmon eggs are of great importance to the diet of both juvenile and adult Dolly Varden. Predators of the Dolly Varden are otters, bears, birds, beluga whales, seals, sea lions, other marine mammals, and humans. 

In southwest Alaska, Dolly Varden spawn during the fall primarily in flowing water. In preparation for spawning, the male establishes a territory that he defends against other fish. Prior to spawning the female selects a location within the male's territory and begins to dig the redd. The male courts the female by circling around her. He then moves alongside her and quivers. The mating pair eject eggs and milt into the small depression and the fertilized eggs are deposited into the gravel. Subsequent digging upstream covers the eggs and protects them from being dislodged by the current.  

The fertilized eggs can hatch after 4 to 8 months, usually before the spring. Young Dolly Varden begin to feed after emerging from the gravel. They may either spend their first few years exclusively in freshwater or in the estuary. Chemical analysis of the bony structures of some Dolly Varden from the Togiak River indicated that these fish usually go to the ocean for the first time at age 1 to 3. Radio tagged fish left the Togiak River and spent between 30 to 60 days at sea. They likely spend each winter in freshwater, although not always in the Togiak River. While at sea these fish can grow rapidly. Dolly Varden studied in the Togiak River return to the Togiak River to spawn for the first time at age 2 to 5.  


Resources   

  • Morrow, James E. 1980. The freshwater fishes of Alaska. Alaska Northwest Publishing Company. Anchorage Alaska.  
  • Information about research done on Dolly Varden within the refuge is on our Science page "Life History of Togiak River Dolly Varden."

Facts About Dolly Varden

 Go to the ocean for the first time at age 1 to 3 years. 

 Color can vary according to maturity, time of year, whether the fish is found in fresh or salt water, and genetic background.